Cell holder and battery device

Abstract

To provide a technology capable of miniaturizing a battery device.SOLUTION: A cell holder holds a plurality of cylindrical battery cells such that the plurality of battery cells connected in series are arranged in a line along the direction perpendicular to the longitudinal direction of the plurality of battery cells. The cell holder includes a cover portion that covers surfaces of the plurality of battery cells. The cover portion includes a first opening that exposes at least one outer peripheral surface of the plurality of battery cells in a first plan view from one side in a vertical direction perpendicular to the arrangement direction and the longitudinal direction of the plurality of battery cells.SELECTED DRAWING: Figure 5

Description

Technical Field

[0007] ,

[0001] The present disclosure relates to a cell holder.

Background Art

[0002] Patent Document 1 describes a technology related to a battery pack including a plurality of battery cells and a holder that holds the plurality of battery cells. Patent Document 2 describes a technology related to a holder that holds a battery cell.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

[0008] The battery device can be made smaller. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram showing an example of the appearance of a battery device. [Figure 2] This is a schematic diagram showing an example of the appearance of a battery device. [Figure 3] This is a schematic diagram showing an example of the appearance of garment 1 with a fan. [Figure 4] This is a schematic diagram showing an example of how a battery unit is connected to a clothing fan. [Figure 5] This is a schematic diagram showing an example of a part of the battery device's configuration. [Figure 6] This is a schematic diagram showing an example of a part of the battery device's configuration. [Figure 7] This is a schematic diagram showing an example of the electrical configuration of a battery device. [Figure 8] This is a schematic diagram showing an example of a part of the battery device's configuration. [Figure 9] This is a schematic diagram showing an example of a part of the battery device's configuration. [Figure 10] This is a schematic diagram showing an example of a part of the battery device's configuration. [Figure 11] This is a schematic diagram showing an example of a part of the battery device's configuration. [Figure 12] This is a schematic diagram showing an example of a part of the battery device's configuration. [Figure 13] This is a schematic diagram showing an example of a part of the battery device's configuration. [Figure 14] This is a schematic diagram showing an example of the configuration of a cell holder. [Figure 15] This is a schematic diagram showing an example of the configuration of a cell holder. [Figure 16] This is a schematic diagram showing an example of a cross-sectional structure of a battery device. [Figure 17] It is a schematic diagram showing an example of a partial cross-sectional structure of a battery device. [Figure 18] It is a schematic diagram showing an example of the configuration of a cell holder. [Figure 19] It is a schematic diagram showing an example of the configuration of a cell holder. [Figure 20] It is a schematic diagram showing an example of a partial configuration of a cell holder. [Figure 21] It is a schematic diagram showing an example of a partial configuration of a cell holder. [Figure 22] It is a schematic diagram showing an example of a partial configuration of a battery device. [Figure 23] It is a schematic diagram showing an example of a partial configuration of a battery device. [Figure 24] It is a schematic diagram showing an example of the configuration of a cell holder. [Figure 25] It is a schematic diagram showing an example of the configuration of a cell holder. [Figure 26] It is a schematic diagram showing an example of a partial cross-sectional structure of a battery device.

Embodiments for Carrying Out the Invention

[0010] FIGS. 1 and 2 are schematic perspective views showing an example of the appearance of the battery device 10. In FIG. 2, an example of the appearance of the battery device 10 viewed from an angle different from that in FIG. 1 is shown. As shown in FIGS. 1 and 2, the battery device 10 includes a case 100. In the case 100, for example, a plurality of battery cells and the like are accommodated. The case 100 constitutes the exterior of the battery device 10. The case 100 can also be said to be an exterior case. Also, the case 100 can be said to be a housing. The outer shape of the case 100 is, for example, substantially rectangular parallelepiped. The battery device 10 is also called a battery pack.

[0011] The battery device 10 can, for example, supply power to a target device. The battery device 10 can, for example, supply a DC voltage to the target device. The target device can be, for example, a clothing fan 3 (also simply referred to as the fan 3) attached to the clothing 2.

[0012] Figure 3 is a schematic diagram showing an example of a fan-equipped garment 1. The fan-equipped garment 1 comprises, for example, a garment 2 and at least one fan 3 attached to the garment 2. In the example in Figure 3, two fans 3 are attached to the garment 2, but the number of fans 3 attached to the garment 2 may be one or three or more. The fans 3 are, for example, detachable from the garment 2.

[0013] The battery unit 10 can supply power to each fan 3. The battery unit 10 is connected to each fan 3 by a cable 4, for example, as shown in Figure 4. The battery unit 10 is housed, for example, in a pocket of clothing 2. The power (in other words, DC voltage) output from the battery unit 10 is supplied to each fan 3 through the cable 4.

[0014] Each fan 3 rotates based on power supplied from the battery unit 10. When the fans 3 are rotating, air from outside the garment 2 is drawn into the garment 2 by the fans 3. The air drawn into the garment 2 circulates within the garment 2 due to the rotation of the fans 3 and is exhausted to the outside of the garment 2 through the neckline or other openings. This cools the body of the wearer of the fan-equipped garment 1, i.e., the user.

[0015] Note that the target device may be something other than the clothing fan 3. For example, the target device may be a heater that can be attached to clothing, a fan or heater that cannot be attached to clothing, or any other device.

[0016] <Overview of an example of a battery device configuration> Figure 5 is a schematic diagram showing an example of the battery device 10 with the case 100 removed, as shown in Figure 1. Figure 6 is a schematic diagram showing an example of the battery device 10 with the case 100 removed, as shown in Figure 2.

[0017] As shown in Figures 5 and 6, the battery device 10 includes, for example, a battery pack 20, a power supply circuit board 30, a control circuit board 40, a wiring member 50, a connecting member 60, a plurality of connecting members 70, a thermistor 80 (see Figure 6), and insulating paper 90 (see Figure 6). These components are housed in a case 100.

[0018] The power supply circuit board 30 can generate a voltage to supply to a target device (e.g., fan 3) based on the voltage output from the battery pack 20. The power supply circuit board 30 can also charge the battery pack 20 based on power supplied from outside the battery device 10. The power supply circuit board 30 can control the discharge and charging of the battery pack 20.

[0019] The thermistor 80 is capable of detecting the temperature of the battery cells 21 in the battery pack 20. The thermistor 80 comprises, for example, a main body 81 which is a resistor, and two lead wires 82 which transmit the detection signal output from the main body 81 to the control circuit board 40. The lead wires 82 are electrically connected to the control circuit board 40. The control circuit board 40 can control the operation of the power supply circuit board 30 based on the detection result from the thermistor 80 (specifically the main body 81). The control circuit board 40 and the power supply circuit board 30 are electrically connected to each other by a plurality of connecting members 70. The control circuit board 40 and the power supply circuit board 30 can operate based on the power from the battery pack 20.

[0020] The wiring component 50 is a component for transmitting the voltage output from the battery pack 20 to the power supply circuit board 30, and is electrically connected to the power supply circuit board 30 by the connecting component 60. The insulating paper 90 is a component for ensuring insulation between the battery cells 21 of the battery pack 20 and the surrounding components.

[0021] The battery unit 10 is capable of outputting a voltage generated by the power supply circuit board 30 based on the voltage from the battery pack 20. The voltage output from the battery unit 10 is supplied to the fan 3 via the cable 4. This supplies power from the battery pack 20 to the fan 3. The fan 3 can operate based on the power from the battery pack 20.

[0022] <An example of the electrical configuration of a battery device> Figure 7 is a block diagram showing an example of the electrical configuration of the battery device 10. As shown in Figure 7, the battery pack 20 comprises, for example, a plurality of battery cells 21. The battery pack 20 comprises, for example, five battery cells 21. The number of plurality of battery cells 21 comprising the battery pack 20 may be less than five or six or more.

[0023] The battery cell 21 is, for example, a rechargeable secondary battery cell. The battery cell 21 is, for example, a lithium-ion battery cell. The nominal voltage of the battery cell 21 is, for example, about 3.6V, and the fully charged voltage of the battery cell 21 is, for example, about 4.2V. The battery cell 21 may be a secondary battery cell other than a lithium-ion battery cell. For example, the battery cell 21 may be a lead-acid battery cell or another type of secondary battery cell. Alternatively, the battery cell 21 may be a primary battery cell such as an alkaline dry cell.

[0024] Multiple battery cells 21 are connected in series, for example. The battery pack 20 outputs the total voltage of the multiple battery cells 21 connected in series. Here, the voltage of a single battery cell 21 is called the cell voltage. The battery pack 20 outputs the total voltage of the cell voltages of, for example, five battery cells 21. If each cell voltage is, for example, 3.6V, the total voltage output from the battery pack 20 will be 18V.

[0025] The total voltage output by the battery pack 20 is input to the power supply circuit board 30 (also simply called the circuit board 30). In addition, the circuit board 30 is input, for example, the potential of the negative terminal of the first-stage battery cell 21 and the potential of the positive terminal of each battery cell 21. Specifically, the circuit board 30 is input the potential V0 of the negative terminal of the first-stage battery cell 21 (also called battery cell 21a), the potential V1 of the positive terminal of the first-stage battery cell 21, the potential V2 of the positive terminal of the second-stage battery cell 21 (also called battery cell 21b), the potential V3 of the positive terminal of the third-stage battery cell 21 (also called battery cell 21c), the potential V4 of the positive terminal of the fourth-stage battery cell 21 (also called battery cell 21d), and the potential V5 of the positive terminal of the fifth-stage battery cell 21 (also called battery cell 21e). Potential V1 is the potential of the negative terminal of the second-stage battery cell 21b, potential V2 is the potential of the negative terminal of the third-stage battery cell 21c, potential V3 is the potential of the negative terminal of the fourth-stage battery cell 21d, and potential V4 is the potential of the negative terminal of the fifth-stage (i.e., final-stage) battery cell 21e. If potential V0 is 0V, then when the voltage of each cell is 3.6V, potentials V1, V2, V3, V4, and V5 will be 3.6V, 7.2V, 10.8V, 14.4V, and 18V, respectively. The total voltage output by the battery pack 20 is the potential difference between potential V5 and potential V0. Hereafter, the total voltage output by the battery pack 20 may be referred to as the battery pack voltage.

[0026] The circuit board 30 includes, for example, a wiring board 31, a protection circuit 32 for protecting the battery pack 20, a power supply unit 33 for generating the voltage supplied to the fan 3, and a connector 34 for connecting to an external device of the battery device 10. The protection circuit 32, the power supply unit 33, and the connector 34 are mounted on the wiring board 31. The wiring board 31 has, for example, multiple wires (also called wiring patterns) formed on it. For example, components are mounted on both sides of the wiring board 31.

[0027] For example, cable 4 (see Figure 4) is connected to connector 34. Also connected to connector 34 is a cable that transmits power (also called charging power) for charging the battery pack 20. The cable connection port on connector 34 is exposed from the case 100. Connector 34 outputs the input charging power to the power supply unit 33.

[0028] The protection circuit 32 can, for example, detect overcharging and over-discharging of the battery cells 21. The protection circuit 32 receives potentials V0 to V5 as input. Based on potentials V0 to V5, the protection circuit 32 determines the cell voltage of each battery cell 21. The protection circuit 32 calculates the potential difference between potential V1 and potential V0 and sets this as the cell voltage of the first-stage battery cell 21. The protection circuit 32 also calculates the potential difference between potential V2 and potential V1 and sets this as the cell voltage of the second-stage battery cell 21. The protection circuit 32 also calculates the potential difference between potential V3 and potential V2 and sets this as the cell voltage of the third-stage battery cell 21. The protection circuit 32 also calculates the potential difference between potential V4 and potential V3 and sets this as the cell voltage of the fourth-stage battery cell 21. Finally, the protection circuit 32 calculates the potential difference between potential V5 and potential V4 and sets this as the cell voltage of the final-stage battery cell 21. The protection circuit 32 outputs an overcharge detection signal to the power supply unit 33 when the cell voltage of at least one of the battery cells 21 exceeds the charge termination voltage (e.g., 4.2V). Furthermore, the protection circuit 32 outputs an over-discharge detection signal to the power supply unit 33 when the cell voltage of at least one of the battery cells 21 falls below the discharge termination voltage (e.g., 3.0V).

[0029] The power supply unit 33 is a circuit composed of, for example, one packaged IC (Integrated Circuit) and multiple discrete components including inductors, capacitors, and semiconductor switching elements (e.g., FETs (Field Effect Transistors)). The power supply unit 33 can also be called a power supply circuit. In this example, the power supply unit 33 can use one IC to step down the battery pack voltage, step up the battery pack voltage, control the charging of the battery pack 20, and control the discharging of the battery pack 20.

[0030] The power supply unit 33 generates a voltage (also called an external supply voltage) to supply to the fan 3 based on the battery pack voltage. The power supply unit 33 then outputs the generated external supply voltage to the connector 34. The connector 34 outputs the input external supply voltage to the fan 3 through the cable 4. The external supply voltage is, for example, a DC voltage. The fan 3 operates based on the external supply voltage. The external supply voltage can also be said to be the power supply voltage of the fan 3.

[0031] The power supply unit 33 can generate, for example, multiple types of external supply voltages with different values. For example, the power supply unit 33 can generate four types of external supply voltages. For example, the power supply unit 33 can output a first external supply voltage with the smallest value, a second external supply voltage with the second smallest value, a third external supply voltage with the third smallest value, and a fourth external supply voltage with the largest value. For example, the first external supply voltage is 6V, the second external supply voltage is 9V, the third external supply voltage is 12V, and the fourth external supply voltage is 17V. The larger the value of the external supply voltage, the greater the airflow of the fan 3. The battery device 10 can set the airflow of the fan 3 in, for example, four stages. For example, the power supply unit 33 sets the value of the external supply voltage based on instructions from the control circuit board 40. When an external supply voltage is supplied to the fan 3, each battery cell 21 discharges.

[0032] When the power supply unit 33 receives an over-discharge detection signal from the protection circuit 32 while outputting the external supply voltage, that is, when the protection circuit 32 detects over-discharge, it stops outputting the external supply voltage. The power supply unit 33 generates the external supply voltage by stepping down or stepping up the battery pack voltage. Here, if the discharge termination voltage is, for example, around 3.0V, the minimum battery pack voltage when the protection circuit 32 detects over-discharge will be around 15V. Therefore, when the power supply unit 33 outputs the external supply voltage, the battery pack voltage may drop to around 15V. When the power supply unit 33 generates a fourth external supply voltage (for example, 17V), if the battery pack voltage is less than 17V, it steps up the battery pack voltage to generate the fourth external supply voltage, and if the battery pack voltage is greater than 17V, it steps down the battery pack voltage to generate the fourth external supply voltage. On the other hand, the power supply unit 33 generates the first external supply voltage (e.g., 6V), the second external supply voltage (e.g., 9V), and the third external supply voltage (e.g., 12V) by stepping down the battery pack voltage.

[0033] The power supply unit 33 can charge each battery cell 21 of the battery pack 20 based on the charging power supplied from the connector 34. If the power supply unit 33 receives an overcharge detection signal from the protection circuit 32 while each battery cell 21 is being charged, it stops charging each battery cell 21.

[0034] The control circuit board 40 (also simply called the circuit board 40) comprises, for example, a wiring board 41, a control unit 42, and an operation button 43. The control unit 42 and the operation button 43 are mounted on the wiring board 41. The wiring board 41 has, for example, multiple wirings (also called wiring patterns) formed on it. The operation button 43 is, for example, a push button, also called an operation switch. The area of ​​the operation button 43 that is pressed by the user is exposed from the case 100. For example, components are mounted on both sides of the wiring board 41.

[0035] The control unit 42 can control the power supply circuit board 30. The control unit 42 can control the power supply unit 33 of the circuit board 30. For example, the control unit 42 can instruct the power supply unit 33 to output an external supply voltage or to stop outputting an external supply voltage. The control unit 42 can also instruct the power supply unit 33 to output the type of external supply voltage.

[0036] All or some of the functions of the control unit 42 may be implemented by hardware circuits that do not require software to implement those functions. Furthermore, the control unit 42 may include at least one processor to provide control and processing capabilities for performing various functions, as will be described in more detail below.

[0037] According to various embodiments, at least one processor may be implemented as a single integrated circuit (IC) or as a plurality of communicably connected integrated circuits (ICs) and / or discrete circuits. At least one processor can be implemented according to various known techniques.

[0038] In one embodiment, the processor includes one or more circuits or units configured to perform one or more data computation procedures or processes by, for example, executing instructions stored in associated memory. In other embodiments, the processor may be firmware (e.g., discrete logic components) configured to perform one or more data computation procedures or processes.

[0039] According to various embodiments, the processor may include one or more processors, controllers, microprocessors, microcontrollers, application-specific integrated circuits (ASICs), digital signal processing devices, programmable logic devices, field-programmable gate arrays, or any combination of these devices or configurations, or other known combinations of devices and configurations, and may perform the functions described below.

[0040] In this example, the control unit 42 is composed of a microcomputer, for example, a CPU (Central Processing Unit) and memory. The control unit 42 can also be called a control circuit. Furthermore, the control unit 42 can be considered a type of computer.

[0041] The control unit 42 can identify operations on the operation button 43. The control unit 42 can control the power supply unit 33 in response to operations on the operation button 43. The operation button 43 functions, for example, as a power button that controls the supply of power to the fan 3. When the power supply unit 33 is not outputting an external supply voltage, and the operation button 43 is pressed for, for example, a predetermined time or longer, the control unit 42 instructs the power supply unit 33 to output an external supply voltage. The power supply unit 33 starts outputting an external supply voltage in response to the instruction from the control unit 42. As a result, the external supply voltage is supplied to the fan 3 as power from the battery device 10, and the fan 3 starts rotating. On the other hand, when the power supply unit 33 is outputting an external supply voltage, and the operation button 43 is pressed for, for example, a predetermined time or longer, the control unit 42 instructs the power supply unit 33 to stop outputting the external supply voltage. The power supply unit 33 stops outputting the external supply voltage in response to the instruction from the control unit 42. As a result, the supply of external supply voltage from the battery device 10 to the fan 3 stops, and the fan 3 stops rotating. The predetermined time is set to, for example, about 1 to 2 seconds.

[0042] The operation button 43 also functions as an adjustment button for adjusting the airflow of the fan 3. When the operation button 43 is pressed for less than a predetermined time while the fan 3 is supplied with an external supply voltage, and the pressure on the operation button 43 is released, the control unit 42 instructs the power supply unit 33 to change the type of external supply voltage to be output. The power supply unit 33 changes the type of external supply voltage to be output in response to the instruction from the control unit 42. As a result, the value of the external supply voltage supplied by the battery device 10 to the fan 3 changes, and the airflow of the fan 3 changes. The external supply voltage supplied to the fan 3 changes cyclically between the first external supply voltage, the second external supply voltage, the third external supply voltage, and the fourth supply voltage each time the operation button 43 is operated. The control unit 42 or the control circuit board 40 can control the fan 3 through the power supply circuit board 30.

[0043] The control unit 42 can control the power supply unit 33 based on the detection result from the thermistor 80, which detects the temperature of the battery cell 21. The control unit 42 determines the temperature of the battery cell 21 (also called the cell temperature) based on the detection result from the thermistor 80. When the cell temperature exceeds a predetermined value (e.g., 50°C) while the power supply unit 33 is outputting an external supply voltage (in other words, while the battery cell 21 is discharging), the control unit 42 instructs the power supply unit 33 to stop outputting the external supply voltage. The power supply unit 33 stops outputting the external supply voltage in response to the instruction from the control unit 42. As a result, the discharge of the battery cell 21 stops when the cell temperature becomes high. Also, when the power supply unit 33 is charging the battery cell 21, if the cell temperature exceeds a predetermined value, the control unit 42 instructs the power supply unit 33 to stop charging the battery cell 21. The power supply unit 33 stops charging the battery cell 21 in response to the instruction from the control unit 42. As a result, the charging of the battery cell 21 stops when the cell temperature becomes high.

[0044] The control circuit board 40 is controlled by the control unit 42 and may include a display unit mounted on the wiring board 41. The display unit may display the set value of the fan speed 3 or the remaining battery level of the battery pack 20. The remaining battery level of the battery pack 20 may be determined, for example, by the power supply unit 33 and notified to the control unit 42. The display unit may include a light-emitting element such as an LED (Light Emitting Diode). The display unit may also include a liquid crystal display panel or an organic EL (Electroluminescence) panel.

[0045] Thus, in this example, the power supply unit 33 can step down the total voltage of multiple battery cells 21 (in other words, the battery pack voltage) and output it. However, if the battery pack voltage is small, for example, when multiple battery cells 21 are connected in parallel, the power supply unit 33 must always step up the battery pack voltage to generate the external supply voltage. In this case, the power consumption of the power supply unit 33 may increase. In this example, since the power supply unit 33 can step down the battery pack voltage to generate the external supply voltage, the power consumption of the power supply unit 33 can be reduced.

[0046] Furthermore, since the power supply unit 33 can also boost the battery pack voltage, it can appropriately generate an external supply voltage even if the battery pack voltage drops.

[0047] <Example of battery pack configuration> Figures 8 and 9 are schematic perspective views showing an example of the configuration of the battery pack 20. Figures 10 and 11 are schematic plan views showing an example of the configuration of the battery pack 20. As shown in Figures 5, 6, 8 to 11, the battery pack 20 includes, in addition to the multiple battery cells 21, a cell holder 22 that holds the multiple battery cells 21, and a plurality of connecting conductive plates 28 (see Figures 8 and 9) that electrically connect the terminals of the multiple battery cells 21.

[0048] Each battery cell 21 is, for example, cylindrical. The cell holder 22 holds the multiple battery cells 21 so that they are arranged in a line along a direction perpendicular to their longitudinal direction. The longitudinal directions of the multiple battery cells 21 are parallel to each other.

[0049] In this disclosure, the structure of the battery device 10 will be described using the XYZ Cartesian coordinate system shown in Figures 1, 2, 5, 6, 8-11, etc. The X-axis extends along the longitudinal direction of the battery cell 21, and the Y-axis extends along the direction of arrangement of the multiple battery cells 21 (in other words, the arrangement direction). The Z-axis extends along a direction perpendicular to the direction of arrangement and longitudinal direction of the multiple battery cells 21. Hereafter, "cell longitudinal direction" refers to the longitudinal direction of the battery cell 21. Also, "cell arrangement direction" or "cell arrangement direction" refers to the direction of arrangement or arrangement of the multiple battery cells 21. Furthermore, for convenience of explanation, the +Z side may be called the upper side, the -Z side the lower side, the +X side the left side, the -X side the right side, the +Y side the rear side, and the -Y side the front side. The Z-axis direction, X-axis direction, and Y-axis direction can also be said to be the up-down direction, left-right direction, and front-back direction, respectively.

[0050] In a group of battery cells 21 directly connected to each other, the first-stage battery cell 21a, the second-stage battery cell 21b, the third-stage battery cell 21c, the fourth-stage battery cell 21d, and the fifth-stage (i.e., final-stage) battery cell 21e are arranged in this order from the +Y side to the -Y side. In the first, third, and fifth-stage battery cells 21, the positive and negative terminals are located on the +X side and -X side, respectively, while in the second and fourth-stage battery cells 21, the positive and negative terminals are located on the -X side and +X side, respectively.

[0051] Multiple battery cells 21 are connected in series with multiple connecting conductive plates 28. Figures 12 and 13 are schematic diagrams showing an example of how multiple battery cells 21 are connected in series with multiple connecting conductive plates 28.

[0052] As shown in Figures 8, 9, 12, and 13, the multiple connecting conductive plates 28 include a connecting conductive plate 28a that electrically connects the positive terminal of the first-stage battery cell 21a to the negative terminal of the second-stage battery cell 21b, a connecting conductive plate 28b that electrically connects the positive terminal of the second-stage battery cell 21b to the negative terminal of the third-stage battery cell 21c, a connecting conductive plate 28c that electrically connects the positive terminal of the third-stage battery cell 21c to the negative terminal of the fourth-stage battery cell 21d, and a connecting conductive plate 28d that electrically connects the positive terminal of the fourth-stage battery cell 21d to the negative terminal of the fifth-stage battery cell 21e. Connecting conductive plates 28a and 28c are located on the +X side with respect to the multiple battery cells 21, while connecting conductive plates 28b and 28d are located on the -X side with respect to the multiple battery cells 21. The connecting conductive plate 28 is connected by welding or other means to the positive terminal of one battery cell 21 and the negative terminal of the other battery cell 21 in two battery cells 21 that are connected in series with each other. The connecting conductive plate 28 is made of a metal such as nickel.

[0053] Each connecting conductive plate 28 is electrically connected to the wiring member 50. Each connecting conductive plate 28 has a connecting projection 280 for connecting the connecting conductive plate 28 to the wiring member 50. Since the terminals of the battery cell 21 are electrically connected to the wiring member 50 by the connecting conductive plate 28 fixed to the terminals of the battery cell 21, the connecting conductive plate 28 can be said to be a component for electrically connecting the terminals of the battery cell 21 to the wiring member 50.

[0054] The battery pack 20 includes two connecting conductive plates 29 in addition to the multiple connecting conductive plates 28. The two connecting conductive plates 29 include a connecting conductive plate 29a for electrically connecting the negative terminal of the first-stage battery cell 21a to the wiring member 50, and a connecting conductive plate 29b for electrically connecting the positive terminal of the final-stage battery cell 21e to the wiring member 50. The connecting conductive plates 29 are made of a metal such as nickel. The connecting conductive plate 29a is connected to the negative terminal of the first-stage battery cell 21a by welding or the like. The connecting conductive plate 29b is connected to the positive terminal of the final-stage battery cell 21e by welding or the like. Each connecting conductive plate 29 is electrically connected to the wiring member 50. As a result, the negative terminal of the first-stage battery cell 21a and the positive terminal of the final-stage battery cell 21e are electrically connected to the wiring member 50. Each connecting conductive plate 29 has a connecting projection 290 for connecting the connecting conductive plate 29 to the wiring member 50.

[0055] The positive and negative terminals of each battery cell 21 are electrically connected to the wiring board 31 of the power supply circuit board 30 by a plurality of connecting conductive plates 28, a plurality of connecting conductive plates 29, and wiring members 50.

[0056] <Example of cell holder configuration> Figures 14 and 15 are schematic perspective views showing an example of the configuration of the cell holder 22. The cell holder 22 is made of, for example, resin. The cell holder 22 clamps each battery cell 21 from the longitudinal direction of the cell. The cell holder 22 includes a cover portion 23 that covers the surface of each battery cell 21.

[0057] The cover portion 23 includes, for example, a first end face cover portion 24 that covers the +X side end faces of the multiple battery cells 21, a second end face cover portion 25 that covers the -X side end faces of the multiple battery cells 21, and multiple inter-cell portions 26. The inter-cell portions 26 are sandwiched between two adjacent battery cells 21 and extend along the longitudinal direction of the cells (in other words, the X-axis direction). The multiple inter-cell portions 26 include an inter-cell portion 26a sandwiched between the first-stage battery cell 21a and the second-stage battery cell 21b, an inter-cell portion 26b sandwiched between the second-stage battery cell 21b and the third-stage battery cell 21c, an inter-cell portion 26c sandwiched between the third-stage battery cell 21c and the fourth-stage battery cell 21d, and an inter-cell portion 26d sandwiched between the fourth-stage battery cell 21d and the fifth-stage battery cell 21e. Each inter-cell portion 26 extends from the first end face cover portion 24 toward the -X side and reaches the second end face cover portion 25. The cell holder 22 clamps each battery cell 21 from the longitudinal direction of the cell by the first end face cover portion 24 contacting the +X side end face of each battery cell 21 and the second end face cover portion 25 contacting the -X side end face of each battery cell 21.

[0058] The first end face cover portion 24 is, for example, a roughly plate-shaped structure extending along the Y-axis. The roughly plate-shaped first end face cover portion 24 is, for example, erected along the YZ plane. The first end face cover portion 24 has an opening 245 that exposes the connecting conductive plates 28a, 28c, and 29b connected to the +X-side terminals of the plurality of battery cells 21.

[0059] The opening 245 has an opening 240 that exposes the portion of the connecting conductive plate 28a that is fixed by welding or the like to the +X side end face (i.e., the positive terminal side end face) of the first stage battery cell 21a. The peripheral edge of the opening 240 in the first end face cover portion 24 covers the peripheral end of the +X side end face of the battery cell 21a.

[0060] The opening 245 has an opening 241 that exposes the portion of the connecting conductive plate 28a that is fixed to the +X side end face (i.e., the end face on the negative terminal side) of the second stage battery cell 21b, and the portion of the connecting conductive plate 28c that is fixed to the +X side end face (i.e., the end face on the positive terminal side) of the third stage battery cell 21c. The peripheral edge of the opening 241 in the first end face cover portion 24 covers the peripheral edge of the +X side end face of the battery cell 21b and the peripheral edge of the +X side end face of the battery cell 21c.

[0061] The opening 245 has an opening 242 that exposes the portion of the connecting conductive plate 28c that is fixed to the +X side end face (i.e., the end face on the negative terminal side) of the fourth stage battery cell 21d, and the connecting conductive plate 29b that is fixed to the +X side end face (i.e., the end face on the positive terminal side) of the fifth stage battery cell 21e. The peripheral edge of the opening 242 in the first end face cover portion 24 covers the peripheral edge of the +X side end face of the battery cell 21d and the peripheral edge of the +X side end face of the battery cell 21e.

[0062] The second end face cover portion 25 is, for example, substantially plate-shaped and extends along the Y-axis. The substantially plate-shaped second end face cover portion 25 is, for example, erected along the YZ plane. The second end face cover portion 25 has an opening 255 that exposes the connecting conductive plates 28b, 28d, and 29a connected to the -X-side terminals of the plurality of battery cells 21.

[0063] The opening 255 has an opening 250 that exposes the connecting conductive plate 29a, which is fixed by welding or the like to the -X side end face (i.e., the end face on the negative terminal side) of the first stage battery cell 21a, and the portion of the connecting conductive plate 28b that is fixed to the -X side end face (i.e., the end face on the positive terminal side) of the second stage battery cell 21b. The peripheral edge of the opening 250 in the second end face cover portion 25 covers the peripheral edge of the -X side end face of the battery cell 21a and the peripheral edge of the -X side end face of the battery cell 21b.

[0064] The opening 255 has an opening 251 that exposes the portion of the connecting conductive plate 28b that is fixed to the -X side end face of the third stage battery cell 21c (i.e., the end face on the negative terminal side) and the portion of the connecting conductive plate 28d that is fixed to the -X side end face of the fourth stage battery cell 21d (i.e., the end face on the positive terminal side). The peripheral edge of the opening 251 in the second end face cover portion 25 covers the peripheral edge of the -X side end face of the battery cell 21c and the peripheral edge of the -X side end face of the battery cell 21d.

[0065] The opening 255 has an opening 252 that exposes the portion of the connecting conductive plate 28d that is fixed to the -X side end face (i.e., the end face on the negative terminal side) of the fifth battery cell 21e. The peripheral edge of the opening 252 in the second end face cover portion 25 covers the peripheral end of the -X side end face of the battery cell 21e.

[0066] Each inter-cell portion 26 is, for example, roughly plate-shaped and extends along the X-axis. The roughly plate-shaped inter-cell portion 26 is, for example, erected along the XZ plane. The inter-cell portion 26 can also be described as an inter-cell wall that separates two adjacent battery cells 21.

[0067] Here, when describing the inter-cell portion 26, the +Y-side battery cell 21 refers to the +Y-side (in other words, rear-side) battery cell 21 of the two battery cells 21 that sandwich the inter-cell portion 26. Similarly, when describing the inter-cell portion 26, the -Y-side battery cell 21 refers to the -Y-side (in other words, front-side) battery cell 21 of the two battery cells 21 that sandwich the inter-cell portion 26. The +Y-side surface (in other words, rear-side) of the inter-cell portion 26 has a region that curves concavely in accordance with the outer peripheral surface 210 of the +Y-side battery cell 21 (also called a concave surface or concave curved surface), and covers the -Y-side region (in other words, front region) of the outer peripheral surface 210 of the +Y-side battery cell 21. The -Y side surface (in other words, the front side) of the intercell portion 26 has a region that curves concavely in accordance with the outer peripheral surface 210 of the -Y side battery cell 21, and covers the +Y side region (rear side region) of the outer peripheral surface 210 of the -Y side battery cell 21.

[0068] The intercell portion 26 has an opening 260 (see Figures 14 and 15) that exposes the -Y side region of the outer circumferential surface 210 of the +Y side battery cell 21 and the +Y side region of the outer circumferential surface 210 of the -Y side battery cell 21. The opening 260 is a through hole that penetrates the intercell portion 26 in its thickness direction (in other words, in the Y-axis direction or front-to-back direction) and reaches from the +Y side surface to the -Y side surface of the intercell portion 26. The opening 260 extends, for example, along the X direction. The intercell portion 26a has an opening 260 that exposes the outer circumferential surfaces 210 of the battery cells 21a and 21b, and the intercell portion 26b has an opening 260 that exposes the outer circumferential surfaces 210 of the battery cells 21b and 21c. The inter-cell portion 26c has an opening 260 that exposes the outer circumferential surfaces 210 of the battery cells 21c and 21d, and the inter-cell portion 26d has an opening 260 that exposes the outer circumferential surfaces 210 of the battery cells 21d and 21e.

[0069] The cover portion 23 includes an outer surface cover portion 270 that covers the outer surface 210 of the first battery cell 21a from the outside (specifically, the +Y side) of the arrangement of multiple battery cells 21, and an outer surface cover portion 275 that covers the outer surface 210 of the fifth battery cell 21e from the outside (specifically, the -Y side) of the arrangement of multiple battery cells 21. The outer surface cover portion 270 covers the +Y side region of the outer surface 210 of the battery cell 21a. The outer surface cover portion 275 covers the -Y side region of the outer surface 210 of the battery cell 21e.

[0070] The rear outer peripheral cover portion 270 has upper cover portions 271 and 272 that cover the upper part of the +Y side region of the outer peripheral surface 210 of the battery cell 21a, and lower cover portions 273 and 274 that cover the lower part of the +Y side region of the outer peripheral surface 210 of the battery cell 21a.

[0071] The upper cover portion 271 and the lower cover portion 273 extend from the first end face cover portion 24 in the -X direction. The upper cover portion 272 and the lower cover portion 274 extend from the second end face cover portion 25 in the +X direction. The upper cover portion 271 and the upper cover portion 272 are spaced apart from each other and aligned in the X direction. The lower cover portion 273 and the lower cover portion 274 are spaced apart from each other and aligned in the X direction.

[0072] The inner surfaces of the upper cover portion 271 and the lower cover portion 273 (in other words, the -Y side surfaces) have regions that curve concavely in accordance with the outer circumferential surface 210 of the battery cell 21a, covering the +X side of the +Y side region of the outer circumferential surface 210 of the battery cell 21a. The inner surfaces of the upper cover portion 272 and the lower cover portion 274 have regions that curve concavely in accordance with the outer circumferential surface 210 of the battery cell 21a, covering the -X side of the +Y side region of the outer circumferential surface 210 of the battery cell 21a.

[0073] The front outer peripheral cover portion 275 has upper cover portions 276 and 277 that cover the upper part of the -Y side region of the outer peripheral surface 210 of the battery cell 21e, and lower cover portions 278 and 279 that cover the lower part of the -Y side region of the outer peripheral surface 210 of the battery cell 21e.

[0074] The upper cover portion 276 and the lower cover portion 278 extend from the first end face cover portion 24 in the -X direction. The upper cover portion 277 and the lower cover portion 279 extend from the second end face cover portion 25 in the +X direction. The upper cover portion 276 and the upper cover portion 277 are spaced apart from each other in the X direction. The lower cover portion 278 and the lower cover portion 279 are spaced apart from each other in the X direction.

[0075] The inner surfaces of the upper cover portion 276 and the lower cover portion 278 (in other words, the +Y side surfaces) have regions that curve concavely in accordance with the outer circumferential surface 210 of the battery cell 21e, covering the +X side of the -Y side region of the outer circumferential surface 210 of the battery cell 21e. The inner surfaces of the upper cover portion 277 and the lower cover portion 279 have regions that curve concavely in accordance with the outer circumferential surface 210 of the battery cell 21e, covering the -X side of the -Y side region of the outer circumferential surface 210 of the battery cell 21e.

[0076] In the cell holder 22, the outer peripheral cover portion 270 and the inter-cell portion 26a hold the outer peripheral surface 210 of the first-stage battery cell 21a, and the inter-cell portions 26a and 26b hold the outer peripheral surface 210 of the second-stage battery cell 21b. Furthermore, the inter-cell portions 26b and 26c hold the outer peripheral surface 210 of the third-stage battery cell 21c, and the inter-cell portions 26c and 26d hold the outer peripheral surface 210 of the fourth-stage battery cell 21d. Finally, the inter-cell portion 26d and the outer peripheral cover portion 275 hold the outer peripheral surface 210 of the last-stage battery cell 21e.

[0077] The cover portion 23 has a first opening 230 that exposes at least one outer peripheral surface 210 of the plurality of battery cells 21 in a first plan view from one side in a vertical direction perpendicular to the cell arrangement direction and the cell longitudinal direction. In other words, as shown in Figures 5, 8, 10, 14, etc., the cover portion 23 has a first opening 230 that exposes at least one outer peripheral surface 210 of the plurality of battery cells 21 in a plan view from the +Z side.

[0078] The first opening 230 exposes, for example, the outer circumferential surface 210 of each of the multiple battery cells 21. The first opening 230 has multiple openings 231 that expose the outer circumferential surfaces 210 of each of the multiple battery cells 21. The multiple openings 231 include an opening 231a that exposes the +Z side (in other words, the upper side) of the outer circumferential surface 210 of battery cell 21a, an opening 231b that exposes the +Z side of the outer circumferential surface 210 of battery cell 21b, an opening 231c that exposes the +Z side of the outer circumferential surface 210 of battery cell 21c, an opening 231d that exposes the +Z side of the outer circumferential surface 210 of battery cell 21d, and an opening 231e that exposes the +Z side of the outer circumferential surface 210 of battery cell 21e. Hereafter, the first opening 230 may be referred to as the upper opening 230, and the openings 231 may be referred to as the upper opening 231.

[0079] Furthermore, the cover portion 23 has a second opening 235 that exposes at least one outer peripheral surface 210 of the plurality of battery cells 21 in a second plan view from the other side in a vertical direction perpendicular to the cell arrangement direction and the cell longitudinal direction. In other words, as shown in Figures 6, 9, 11, 15, etc., the cover portion 23 has a second opening 235 that exposes at least one outer peripheral surface 210 of the plurality of battery cells 21 in a plan view from the -Z side.

[0080] The second opening 235 exposes, for example, the outer circumferential surface 210 of each of the multiple battery cells 21. The second opening 235 has multiple openings 236 that expose the outer circumferential surfaces 210 of each of the multiple battery cells 21. The multiple openings 236 include an opening 236a that exposes the -Z side (in other words, the lower side) of the outer circumferential surface 210 of battery cell 21a, an opening 236b that exposes the -Z side of the outer circumferential surface 210 of battery cell 21b, an opening 236c that exposes the -Z side of the outer circumferential surface 210 of battery cell 21c, an opening 236d that exposes the -Z side of the outer circumferential surface 210 of battery cell 21d, and an opening 236e that exposes the -Z side of the outer circumferential surface 210 of battery cell 21e. Hereafter, the second opening 235 may be referred to as the lower opening 235, and the openings 236 may be referred to as the lower opening 236.

[0081] The upper opening 230 and the lower opening 235 are defined by the first end face cover portion 24, the second end face cover portion 25, the multiple inter-cell portions 26, and the outer peripheral cover portions 270 and 275. The upper opening 231a is defined by the first end face cover portion 24, the second end face cover portion 25, the upper cover portions 271 and 272 of the outer peripheral cover portion 270, and the upper end of the inter-cell portion 26a. The upper opening 231b is defined by the first end face cover portion 24, the second end face cover portion 25, the upper end of the inter-cell portion 26a, and the upper end of the inter-cell portion 26b. The upper opening 231c is defined by the first end face cover portion 24, the second end face cover portion 25, the upper end of the inter-cell portion 26b, and the upper end of the inter-cell portion 26c. The upper opening 231d is defined by the first end face cover portion 24, the second end face cover portion 25, the upper end of the inter-cell portion 26c, and the upper end of the inter-cell portion 26d. The upper opening 231e is defined by the first end face cover portion 24, the second end face cover portion 25, the upper end of the inter-cell portion 26d, and the upper cover portions 276 and 277 of the outer peripheral cover portion 275.

[0082] The lower opening 236a is defined by the first end face cover portion 24, the second end face cover portion 25, the lower cover portions 273 and 274 of the outer peripheral cover portion 270, and the lower end of the inter-cell portion 26a. The lower opening 236b is defined by the first end face cover portion 24, the second end face cover portion 25, the lower end of the inter-cell portion 26a, and the lower end of the inter-cell portion 26b. The lower opening 236c is defined by the first end face cover portion 24, the second end face cover portion 25, the lower end of the inter-cell portion 26b, and the lower end of the inter-cell portion 26c. The lower opening 236d is defined by the first end face cover portion 24, the second end face cover portion 25, the lower end of the inter-cell portion 26c, and the lower end of the inter-cell portion 26d. The lower opening 236e is defined by the first end face cover portion 24, the second end face cover portion 25, the lower end of the inter-cell portion 26d, and the lower cover portions 278 and 279 of the outer peripheral cover portion 275.

[0083] Figure 16 is a schematic diagram showing an example of the cross-sectional structure of the case 100, cell holder 22, and multiple battery cells 21. Figure 16 shows an example of the cross-sectional structure of the case 100, cell holder 22, and multiple battery cells 21 in a first cross-sectional view in a plane perpendicular to the longitudinal direction of the cells (in other words, the YZ plane). Since the first cross-sectional view is also a cross-sectional view along the direction of cell arrangement, the first cross-sectional view is sometimes called a cell arrangement direction cross-sectional view. Also, the outer circumferential surface 210 of the battery cell 21 is sometimes called the cell outer circumferential surface 210. In Figure 16, the cross-sectional structure of the case 100, cell holder 22, and multiple battery cells 21 is indicated by diagonal lines.

[0084] As shown in Figure 16, with respect to each upper opening 231, in a cross-sectional view in the direction of cell alignment, the cross-sectional structure of the peripheral edge 238 of the upper opening 231 in the cover portion 23 does not protrude above (in other words, to the +Z side) the vertex 211a of the exposed surface 211 (also called the upper exposed surface 211) that is exposed from the upper opening 231 on the outer circumferential surface 210 of the battery cell 21. For example, with respect to the upper opening 231a, in a cross-sectional view in the direction of cell alignment, the cross-sectional structure of the peripheral edge 238 of the upper opening 231a in the cover portion 23 does not protrude above the vertex 211a of the upper exposed surface 211 that is exposed from the upper opening 231a on the outer circumferential surface 210 of the battery cell 21a. Furthermore, with respect to the upper opening 231e, in a cross-sectional view in the direction of cell alignment, the cross-sectional structure of the peripheral edge 238 of the upper opening 231e in the cover portion 23 does not protrude above the vertex 211a of the upper exposed surface 211 that is exposed from the upper opening 231e on the outer peripheral surface 210 of the battery cell 21e. In the example of Figure 16, in a cross-sectional view in the direction of cell alignment, the cross-sectional structure of the peripheral edge 238 of the upper opening 231 in the cover portion 23 is located below (in other words, on the -Z side) the vertex 211a of the upper exposed surface 211 of the battery cell 21. In a cross-sectional view in the direction of cell alignment, the vertex 211a of the upper exposed surface 211 can be said to be the uppermost part of the upper exposed surface 211.

[0085] In this example, in a cross-sectional view in the direction of cell alignment, all surfaces of the cell holder 22 that are visible in a plan view from the +Z side (in other words, the +Z side surfaces of the cell holder 22) are located below the vertex 211a of the upper exposed surface 211 of each battery cell 21. In other words, in a cross-sectional view in the direction of cell alignment, all surfaces of the cover portion 23 that are visible in a plan view from the +Z side are located below the vertex 211a of the upper exposed surface 211 of each battery cell 21.

[0086] Furthermore, in a cross-sectional view in the direction of cell arrangement, the uppermost part of the cross-sectional structure of the peripheral edge 238 of the upper opening 231 in the cover portion 23 may be located at the same position as the vertex 211a of the upper exposed surface 211 of the battery cell 21 in the Z-axis direction. For example, in a cross-sectional view in the direction of cell arrangement, the uppermost part of the cross-sectional structure of the peripheral edge 238 of the upper opening 231b in the cover portion 23 may be located at the same position as the vertex 211a of the upper exposed surface 211 of the battery cell 21b in the Z-axis direction. Also, in a cross-sectional view in the direction of cell arrangement, the uppermost part of the surface visible in a plan view from the +Z side of the cell holder 22 may be located at the same position as the vertex 211a of the upper exposed surface 211 of each battery cell 21 in the Z-axis direction.

[0087] As shown in Figure 16, with respect to each lower opening 236, in a cross-sectional view in the direction of cell alignment, the cross-sectional structure of the peripheral edge 239 of the lower opening 236 in the cover portion 23 does not protrude below (in other words, to the -Z side) the apex 212a of the exposed surface 212 (also called the lower exposed surface 212) that is exposed from the lower opening 236 on the outer circumferential surface 210 of the cell. For example, with respect to the lower opening 236c, in a cross-sectional view in the direction of cell alignment, the cross-sectional structure of the peripheral edge 239 of the lower opening 236c in the cover portion 23 does not protrude below the apex 212a of the lower exposed surface 212 that is exposed from the lower opening 236c on the outer circumferential surface 210 of the battery cell 21c. Furthermore, with respect to the lower opening 236d, the cross-sectional structure of the peripheral edge 238 of the lower opening 236d in the cover portion 23 does not protrude below the apex 212a of the lower exposed surface 212 that is exposed from the lower opening 236d on the outer peripheral surface 210 of the battery cell 21d, in a cross-sectional view in the direction of cell alignment. In the example of Figure 16, in a cross-sectional view in the direction of cell alignment, the cross-sectional structure of the peripheral edge 238 of the lower opening 236 in the cover portion 23 is located above the apex 212a of the lower exposed surface 212 of the battery cell 21. In a cross-sectional view in the direction of cell alignment, the apex 212a of the lower exposed surface 212 can be said to be the lowest part of the lower exposed surface 212.

[0088] In this example, in a cross-sectional view in the direction of cell alignment, all surfaces of the cell holder 22 that are visible in a plan view from the -Z side (in other words, the -Z side surfaces of the cell holder 22) are located above the vertex 212a of the lower exposed surface 212 of each battery cell 21. In other words, in a cross-sectional view in the direction of cell alignment, all surfaces of the cover portion 23 that are visible in a plan view from the -Z side are located above the vertex 212a of the lower exposed surface 212 of each battery cell 21.

[0089] Furthermore, in a cross-sectional view in the direction of cell alignment, the lowest part of the cross-sectional structure of the peripheral edge 239 of the lower opening 236 in the cover portion 23 may be located at the same position in the Z-axis direction as the vertex 212a of the lower exposed surface 212 of the battery cell 21. For example, in a cross-sectional view in the direction of cell alignment, the lowest part of the cross-sectional structure of the peripheral edge 239 of the lower opening 236b in the cover portion 23 may be located at the same position in the Z-axis direction as the vertex 212a of the lower exposed surface 212 of the battery cell 21b. Also, in a cross-sectional view in the direction of cell alignment, the lowest part of the surface visible in a plan view from the -Z side of the cell holder 22 may be located at the same position in the Z-axis direction as the vertex 212a of the lower exposed surface 212 of each battery cell 21.

[0090] As shown in Figure 10, for each battery cell 21, in a plan view from the +Z side, both ends 215 of the outer circumferential surface 210 of the cell in the longitudinal direction are exposed from the upper opening 231 of the cover portion 23. For example, for battery cell 21c, in a plan view from the +Z side, both ends 215 of the outer circumferential surface 210 of battery cell 21c in the longitudinal direction are exposed from the upper opening 231c. Similarly, for battery cell 21d, in a plan view from the +Z side, both ends 215 of the outer circumferential surface 210 of battery cell 21d in the longitudinal direction are exposed from the upper opening 231d. Hereafter, the left end 215 of the outer circumferential surface 210 in the longitudinal direction of the cell (in other words, the +X side) may be referred to as the left end 215a, and the right end 215 of the outer circumferential surface 210 in the longitudinal direction of the cell (in other words, the -X side) may be referred to as the right end 215b.

[0091] As shown in Figure 11, for each battery cell 21, in a plan view from the -Z side, both ends 215 of the outer circumferential surface 210 in the longitudinal direction of the cell are exposed from the lower opening 236 of the cover portion 23. For example, for battery cell 21a, in a plan view from the -Z side, both ends 215 of the outer circumferential surface 210 of battery cell 21a in the longitudinal direction of the cell are exposed from the lower opening 236a. Similarly, for battery cell 21e, in a plan view from the -Z side, both ends 215 of the outer circumferential surface 210 of battery cell 21e in the longitudinal direction of the cell are exposed from the lower opening 236e.

[0092] Furthermore, in a plan view from the +Z side, one of the left end 215a and the right end 215b of the cell outer periphery 210 does not have to be exposed from the upper opening 231. In other words, in a plan view from the +Z side, the entire area of ​​one of the left end 215a and the right end 215b of the cell outer periphery 210 may be covered by the cover portion 23. Also, in a plan view from the +Z side, the left end 215a and the right end 215b of the cell outer periphery 210 do not have to be exposed from the upper opening 231. Furthermore, in a plan view from the -Z side, one of the left end 215a and the right end 215b of the cell outer periphery 210 does not have to be exposed from the lower opening 236. Also, in a plan view from the -Z side, the left end 215a and the right end 215b of the cell outer periphery 210 do not have to be exposed from the lower opening 236.

[0093] Figure 17 is a schematic diagram showing an example of the cross-sectional structure of a cell holder 22 and a battery cell 21. Figure 17 shows an example of the cross-sectional structure of a cell holder 22 and a battery cell 21 in a second cross-sectional view in a plane perpendicular to the cell alignment direction, passing through the central axis of the battery cell 21. The central axis of the battery cell 21 extends along the X-axis direction. In Figure 17, the cross-sectional structure of the cell holder 22 and the battery cell 21 is indicated by diagonal lines. Since the second cross-sectional view is also a cross-sectional view along the longitudinal direction of the cell, the second cross-sectional view is sometimes called a longitudinal cell cross-sectional view. Figure 17 shows a representative cross-sectional structure of battery cell 21c among multiple battery cells 21. In Figure 17, the cross-sectional structure of the cell holder 22 and the battery cell 21 is indicated by diagonal lines.

[0094] As shown in Figure 17, in a longitudinal cross-sectional view of the cell, the cross-sectional structure of each upper peripheral edge 238 (also called the longitudinal cross-sectional structure of the upper peripheral edge) does not protrude above the outer circumferential surface 210 of the battery cell 21 (in other words, to the +Z side). For example, in a longitudinal cross-sectional view of the cell, the cross-sectional structure of the peripheral edge 238 of the upper opening 231c in the cover portion 23 does not protrude above the outer circumferential surface 210 of the battery cell 21c. Similarly, in a longitudinal cross-sectional view of the cell, the cross-sectional structure of the peripheral edge 238 of the upper opening 231d in the cover portion 23 does not protrude above the outer circumferential surface 210 of the battery cell 21d.

[0095] In this example, in a longitudinal cross-sectional view of the cell, the first portion 238a on the left end 215a side (in other words, the +X side) of the cell outer surface 210 in the longitudinal cross-sectional structure of the upper peripheral edge does not protrude beyond the cell outer surface 210 to the +Z side. Also, in a longitudinal cross-sectional view of the cell, the second portion 238b on the right end 215b side (in other words, the -X side) of the cell outer surface 210 in the longitudinal cross-sectional structure of the upper peripheral edge does not protrude beyond the cell outer surface 210 to the +Z side. In a longitudinal cross-sectional view of the cell, the first portion 238a partially covers the +X side end face of the battery cell 21, and the second portion 238b partially covers the -X side end face of the battery cell 21.

[0096] Furthermore, in a longitudinal cross-sectional view of the cell, the cross-sectional structure of each lower peripheral edge 239 (also referred to as the longitudinal cross-sectional structure of the lower peripheral edge) does not protrude below the outer circumferential surface 210 of the battery cell 21 (in other words, to the -Z side). For example, in a longitudinal cross-sectional view of the cell, the cross-sectional structure of the peripheral edge 239 of the lower opening 236c in the cover portion 23 does not protrude beyond the outer circumferential surface 210 of the battery cell 21c. Similarly, in a longitudinal cross-sectional view of the cell, the cross-sectional structure of the peripheral edge 239 of the lower opening 236b in the cover portion 23 does not protrude beyond the outer circumferential surface 210 of the battery cell 21b.

[0097] In this example, in a longitudinal cross-sectional view of the cell, the first portion 239a on the left end 215a side of the cell outer surface 210 in the longitudinal cross-sectional structure of the lower peripheral edge does not protrude beyond the cell outer surface 210 to the -Z side. Also, in a longitudinal cross-sectional view of the cell, the second portion 239b on the right end 215b side of the cell outer surface 210 in the longitudinal cross-sectional structure of the lower peripheral edge does not protrude beyond the cell outer surface 210 to the -Z side. In a longitudinal cross-sectional view of the cell, the first portion 239a partially covers the +X side end face of the battery cell 21, and the second portion 239b partially covers the -X side end face of the battery cell 21.

[0098] Furthermore, one of the first portion 238a and the second portion 238b of the upper peripheral longitudinal cross-sectional structure may protrude above the cell outer surface 210. Also, each of the first portion 238a and the second portion 238b may protrude above the cell outer surface 210. Furthermore, one of the first portion 238a and the second portion 239b of the lower peripheral longitudinal cross-sectional structure may protrude below the cell outer surface 210. Also, each of the first portion 239a and the second portion 239b may protrude below the cell outer surface 210.

[0099] As shown in Figures 5, 8, 10, 14, and 16, the surface visible in a plan view from the +Z side of the inter-cell portion 26 (in other words, the +Z side surface of the inter-cell portion 26) has a groove-shaped concave surface 265 that extends along the longitudinal direction of the cell and has openings at both ends. The opening on the +X side of the groove-shaped concave surface 265 is visible in a plan view from the +X side of the battery pack 20. The opening on the -X side of the groove-shaped concave surface 265 is visible in a plan view from the -X side of the battery pack 20. The groove-shaped concave surface 265 extends from end to end in the X-axis direction on the surface visible in a plan view from the +Z side of the inter-cell portion 26 (in other words, the +Z side surface of the inter-cell portion 26).

[0100] As shown in Figures 6, 9, 11, 15, and 16, two weight-reducing cutouts 268 are provided in the intercellular portion 26, opening onto the surface visible in a plan view from the -Z side (in other words, the -Z side surface of the intercellular portion 26). The two weight-reducing cutouts 268 are aligned, for example, along the X-axis direction.

[0101] The cell holder 22 includes, for example, a first part holder 2200 and a second part holder 2250 that sandwich a plurality of battery cells 21 from the longitudinal direction. The first part holder 2200 and the second part holder 2250 constitute a cover portion 23. The cell holder 22 can be divided into two parts, for example, a first part holder 2200 and a second part holder 2250. The first part holder 2200 and the second part holder 2250 are attached to each other. The first part holder 2200 and the second part holder 2250 can be separated, for example, along the X-axis direction. The first part holder 2200 is located on the +X side, and the second part holder 2250 is located on the -X side.

[0102] Figures 18 and 19 are schematic perspective views showing an example of how the first part holder 2200 and the second part holder 2250 are separated from each other. The first part holder 2200 comprises a first end face cover portion 24, upper cover portions 271, 276, lower cover portions 273, 278, and a plurality of inter-cell first portions 2210. One inter-cell first portion 2210 constitutes approximately half of the +X side of one inter-cell portion 26. The second part holder 2250 comprises a second end face cover portion 25, upper cover portions 272, 277, lower cover portions 274, 279, and a plurality of inter-cell second portions 2260 having engaging claws. One inter-cell second portion 2260 constitutes approximately half of the -X side of one inter-cell portion 26. The inter-cell portion 26 is composed of a first inter-cell portion 2210 and a second inter-cell portion 2260.

[0103] The first part holder 2200 has the same number of inter-cell first parts 2210 as the number of inter-cell parts 26. The multiple inter-cell first parts 2210 are aligned along the Y-axis. The second part holder 2250 has the same number of inter-cell second parts 2260 as the number of inter-cell parts 26. The multiple inter-cell second parts 2260 are aligned along the Y-axis. In the cell holder 22, for example, the multiple inter-cell first parts 2210 and the multiple inter-cell second parts 2260 are attached to each other, thereby attaching the first part holder 2200 and the second part holder 2250 to each other.

[0104] Figures 20 and 21 are schematic diagrams showing an example configuration of the first inter-cell portion 2210 and the second inter-cell portion 2260. In Figures 20 and 21, a pair of the first inter-cell portion 2210 and the second inter-cell portion 2260, which are attached to each other, are shown separated from each other.

[0105] The first inter-cell portion 2210 includes, for example, an upper portion 2220 located on the +Z side, a lower portion 2230 located on the -Z side, and a connecting portion 2240 that connects the upper portion 2220 and the lower portion 2230. The upper portion 2220 and the lower portion 2230 extend from the first end face cover portion 24 in the -X direction. The connecting portion 2240 extends along the Z axis direction. The +Z end of the connecting portion 2240 is connected to the +X end of the upper portion 2220, and the -Z end of the connecting portion 2240 is connected to the +X end of the lower portion 2230.

[0106] The second inter-cell portion 2260 includes, for example, an upper portion 2270 located on the +Z side, a lower portion 2280 located on the -Z side, and a connecting portion 2290 that connects the upper portion 2270 and the lower portion 2280. The upper portion 2270 and the lower portion 2280 extend from the second end face cover portion 25 in the +X direction. The connecting portion 2290 extends along the Z axis direction. The +Z end of the connecting portion 2290 is connected to the -X end of the upper portion 2270, and the -Z end of the connecting portion 2290 is connected to the -X end of the lower portion 2280.

[0107] The surface of the upper portion 2220 that is visible in a plan view from the +Z side (in other words, the upper surface of the upper portion 2220 on the +Z side) constitutes the +X side portion of the groove-shaped concave surface 265. The surface of the upper portion 2270 that is visible in a plan view from the +Z side (in other words, the surface of the upper portion 2270 on the +Z side) constitutes the -X side portion of the groove-shaped concave surface 265. A weight-reducing portion 268 is formed on the +X side of the lower portion 2230, and a weight-reducing portion 268 is formed on the -X side of the lower portion 2280.

[0108] An engagement hole 2221 is provided at the -X end of the upper portion 2220. The engagement hole 2221 is a through hole that penetrates the -X end of the upper portion 2220 in the Z-axis direction. An engagement claw 2271 that engages with the engagement hole 2221 is provided on the +Z side surface of the +X end of the upper portion 2270. The engagement claw 2271 protrudes in the +Z direction and engages with the engagement hole 2221 from the -Z side. The upper portion 2220 and the upper portion 2270 are attached to each other by the engagement of the engagement hole 2221 and the engagement claw 2271.

[0109] A pair of engagement holes 2221 and engagement claws 2271 are located between two adjacent battery cells 21 in the Y-axis direction. In other words, a pair of engagement holes 2221 and engagement claws 2271 are sandwiched between two adjacent battery cells 21. To put it another way, a pair of engagement holes 2221 and engagement claws 2271 are located in the space between two adjacent battery cells 21. For example, the engagement holes 2221 and engagement claws 2271 of the first inter-cell portion 2210 and the second inter-cell portion 2260 that constitute the inter-cell portion 26a are located between the first-stage battery cell 21a and the second-stage battery cell 21b. The multiple engagement holes 2221 of each of the multiple first inter-cell portion 2210 are aligned along the Y-axis direction. Similarly, the multiple engagement claws 2271 of each of the multiple second inter-cell portion 2260 are aligned along the Y-axis direction.

[0110] An engagement hole 2231 is provided at the -X end of the lower portion 2230. The engagement hole 2231 is a through hole that penetrates the -X end of the lower portion 2230 in the Z-axis direction. An engagement claw 2281 that engages with the engagement hole 2231 is provided on the -Z surface of the lower portion 2280. The engagement claw 2281 protrudes in the -Z direction and engages with the engagement hole 2231 from the +Z side. The lower portion 2230 and the lower portion 2280 are attached to each other by the engagement of the engagement hole 2231 and the engagement claw 2281.

[0111] A pair of engagement holes 2231 and engagement claws 2281 are located between two battery cells 21 that are adjacent to each other in the Y-axis direction. For example, the engagement holes 2231 and engagement claws 2281 of the first inter-cell portion 2210 and the second inter-cell portion 2260 that constitute the inter-cell portion 26b are located in the space between the second-stage battery cell 21b and the third-stage battery cell 21c. The multiple engagement holes 2231 of each of the multiple first inter-cell portions 2210 are aligned along the Y-axis direction. Similarly, the multiple engagement claws 2281 of each of the multiple second inter-cell portions 2260 are aligned along the Y-axis direction.

[0112] The first intercellular portion 2210 having engagement holes 2221 and 2231 can also be called the perforated portion 2210, and the second intercellular portion 2260 having engagement claws 2271 and 2281 can also be called the clawed portion 2260.

[0113] In the inter-cell portion 26, the space enclosed by the upper portions 2220 and 2270 attached to each other, the lower portions 2230 and 2280 attached to each other, the connecting portion 2240 connecting the upper portion 2220 and the lower portion 2230, and the connecting portion 2290 connecting the upper portion 2270 and the lower portion 2280 constitutes the aforementioned opening 260.

[0114] A guide groove 2212 is provided on the -Z side surface of the upper portion 2220 to guide the engagement of the engagement hole 2221 and the engagement claw 2271. The guide groove 2212 is located on the -X side of the engagement hole 2221 and extends from the -X side end of the upper portion 2220 to the engagement hole 2221. The engagement claw 2271 is inserted into the guide groove 2212 from the -X side.

[0115] The lower portions 2230 and 2280 are provided with guide projections 2232 and guide grooves 2282, respectively, to guide the engagement of the engagement hole 2231 and the engagement claw 2281. The guide projection 2232 is provided on the +Z side of the lower portion 2230. The guide projection 2232 is located on the +X side of the engagement hole 2231 and extends along the X-axis toward the engagement hole 2231. The guide groove 2282 is provided on the -Z side of the lower portion 2280. The guide groove 2282 is located on the +X side of the engagement claw 2281 and extends from near the engagement claw 2281 to the +X side end of the lower portion 2280. The guide projection 2232 is inserted into the guide groove 2282 from the +X side. Additionally, the +Z side of the lower portion 2230 is provided with a guide groove 2233, which guides the engagement of the engagement hole 2231 and the engagement claw 2281. The guide groove 2233 is located on the -X side of the engagement hole 2231 and extends from the -X side end of the lower portion 2230 to the engagement hole 2231. The engagement claw 2281 is inserted into the guide groove 2233 from the -X side.

[0116] The first part holder 2200 and the second part holder 2250 are brought closer to each other along the X-axis direction and are mounted to each other so as to sandwich a plurality of battery cells 21 from the longitudinal direction of the cells. When the first part holder 2200 and the second part holder 2250 are brought closer to each other along the X-axis direction, the plurality of engagement holes 2221 and the plurality of engagement claws 2271 aligned along the Y-axis engage with each other, and the plurality of engagement holes 2231 and the plurality of engagement claws 2281 aligned along the Y-axis engage with each other. At this time, the engagement claws 2271 are guided to the engagement holes 2221 by moving relatively within the guide groove 2212 and engage with the engagement holes 2221. Also, the guide projection 2232 moves relatively within the guide groove 2282 and the engagement claws 2281 move relatively within the guide groove 2233, thereby guiding the engagement claws 2281 to the engagement holes 2231 and engaging with the engagement holes 2231. The first part holder 2200 and the second part holder 2250 are attached to each other by the engagement of multiple engagement holes 2221 and multiple engagement claws 2271 with each other, and by the engagement of multiple engagement holes 2231 and multiple engagement claws 2281 with each other. In the cell holder 22, the mounting structure 220 for attaching the first part holder 2200 and the second part holder 2250 to each other is configured with multiple engagement holes 2221, multiple engagement claws 2271 that engage with each of the multiple engagement holes 2221, multiple engagement holes 2231, and multiple engagement claws 2281 that engage with each of the multiple engagement holes 2231.

[0117] With the cell holder 22 having the above configuration, multiple battery cells 21 connected in series are held in place. For example, even if the coating on the outer surface 210 of two adjacent battery cells 21 is damaged, the inter-cell portion 26 makes it difficult for a short circuit to occur between the positive or negative electrodes of the two battery cells 21. Furthermore, when multiple battery cells 21 are connected in series by multiple connecting conductive plates 28 as shown in Figures 12 and 13, the multiple battery cells 21 tend to open up in an accordion-like manner. However, by holding the multiple battery cells 21 with the cell holder 22, it becomes more difficult for the multiple battery cells 21 to open up in an accordion-like manner. Therefore, the assembly workability of the battery device 10 is improved.

[0118] In the example above, groove-shaped concave surfaces 265 are provided on the +Z side surfaces of each of the intercellular portions 26a to 26d, but groove-shaped concave surfaces 265 do not have to be provided on some of the +Z side surfaces of the intercellular portions 26a to 26d. Also, groove-shaped concave surfaces 265 do not have to be provided on all of the +Z side surfaces of the intercellular portions 26a to 26d. Furthermore, groove-shaped concave surfaces similar to those of the groove-shaped concave surfaces 265 may be provided on at least one of the -Z side surfaces of the intercellular portions 26a to 26d.

[0119] Furthermore, in the cell holder 22 described above, the upper first opening 230 provided in the cover portion 23 exposes all of the outer peripheral surfaces 210 of the battery cells 21a to 21e, but it is not necessary to expose some of the outer peripheral surfaces 210 of the battery cells 21a to 21e. In other words, the +Z side region of some of the outer peripheral surfaces 210 of the battery cells 21a to 21e may be covered by the cover portion 23. Similarly, the lower second opening 235 provided in the cover portion 23 does not need to expose some of the outer peripheral surfaces 210 of the battery cells 21a to 21e. In other words, the -Z side region of some of the outer peripheral surfaces 210 of the battery cells 21a to 21e may be covered by the cover portion 23.

[0120] Furthermore, an opening 260 is not required in at least one of the inter-cell portions 26a to 26. Also, in the outer peripheral cover portion 270, the upper cover portion 271 and the upper cover portion 272 may be connected to each other, and the lower cover portion 273 and the lower cover portion 274 may be connected to each other. In addition, the outer peripheral cover portion 270 may be configured to cover most of the +Y side region of the outer peripheral surface of the battery cell 21a. Similarly, in the outer peripheral cover portion 275, the upper cover portion 276 and the upper cover portion 277 may be connected to each other, and the lower cover portion 278 and the lower cover portion 279 may be connected to each other. Furthermore, the outer peripheral cover portion 275 may be configured to cover most of the -Y side region of the outer peripheral surface of the battery cell 21e. Also, the entire area of ​​at least one outer peripheral surface 210 of the battery cells 21a to 21e may be covered by the cover portion 23.

[0121] Furthermore, in the above example, the first part holder 2200 and the second part holder 2250 are attached to each other by the engagement of the engaging claws and the engaging holes, but they may be attached to each other by other means. For example, the first part holder 2200 and the second part holder 2250 may be attached to each other using screws. Alternatively, the first part holder 2200 and the second part holder 2250 may be attached to each other using a combination of an engaging structure consisting of engaging claws and engaging holes and screws.

[0122] <Example of case configuration> As shown in Figures 1, 2, and 16, the roughly rectangular case 100 comprises an upper wall portion 110 and a lower wall portion 120 facing each other, and a side wall portion 130 connecting the peripheral ends of the upper wall portion 110 and the peripheral ends of the lower wall portion 120. The side wall portion 130 surrounds the respective peripheries of the upper wall portion 110 and the lower wall portion 120. The upper wall portion 110 and the lower wall portion 120 extend planarly along the XY plane. The case 100 can be divided into two parts, for example, in the vertical direction (in other words, the Z direction). The case 100 may be divided into two or more parts, or it may not be divided into multiple parts.

[0123] The upper wall portion 110 covers the upper surface of the battery pack 20, and the lower wall portion 120 covers the lower surface of the battery pack 20. As shown in Figures 1, 2, and 16, the upper wall portion 110 has a concave curved portion 111 that is recessed along the groove-shaped concave surface 265 of the inter-cell portion 26 of the cell holder 22. The upper wall portion 110 includes, for example, a concave curved portion 111a that is recessed along the groove-shaped concave surface 265 of the inter-cell portion 26b, a concave curved portion 111b that is recessed along the groove-shaped concave surface 265 of the inter-cell portion 26c, and a concave curved portion 111c that is recessed along the groove-shaped concave surface 265 of the inter-cell portion 26d. In the example shown in Figures 1, 2, and 16, the upper wall portion 110 is not recessed along the groove-shaped concave surface 265 of the intercellular portion 26a, but it may have a concave curved portion 111 that is recessed along the groove-shaped concave surface 265 of the intercellular portion 26a.

[0124] The concave curved portion 111 is recessed on the -Z side and extends along the X-axis direction. The concave curved portion 111 extends from one end of the upper wall portion 110 along the X-axis direction to the other. The concave curved portion 111 has a shape in which an elongated plate portion extending along the X-axis direction is bent concavely in its short-side direction. Multiple concave curved portions 111a, 111b, and 111c are arranged along the Y-axis direction.

[0125] The concave surface 1110 formed by the concave curved portion 111 constitutes a part of the outer surface of the upper wall portion 110 (in other words, the surface on the +Z side). The outer surface of the upper wall portion 110 has three concave surfaces 1110, each formed by the concave curved portions 111a, 111b, and 111c. The concave surface 1110 has a shape corresponding to the groove-shaped concave surface 265 of the intercellular portion 26b. The concave surface 1110 extends along the X-axis direction. The concave surface 1110 extends from one end to the other in the X-axis direction of the outer surface of the upper wall portion 110. The concave surface 1110 can also be described as a shallow groove-shaped surface. The multiple concave surfaces 1110 are arranged along the Y-axis direction.

[0126] The upper wall portion 110 has a convex curved portion 112 that is convex along the outer circumferential surface 210 of the battery cell 21, between two concave curved portions 111 that are adjacent to each other in the Y-axis direction. The upper wall portion 110 includes, for example, a convex curved portion 112a located between the concave curved portion 111a and the concave curved portion 111b, and a convex curved portion 112b located between the concave curved portion 111b and the concave curved portion 111c. The convex curved portion 112a is curved according to the outer circumferential surface 210 of the battery cell 21c, and the convex curved portion 112b is curved according to the outer circumferential surface 210 of the battery cell 21d.

[0127] The convex curved portion 112 is convex towards the +Z side and extends along the X-axis direction. The convex curved portion 112 extends from one end of the upper wall portion 110 along the X-axis direction to the other. The convex curved portion 112 has a shape in which an elongated plate portion extending along the X-axis direction is bent convexly in its shorter direction. The concave curved portion 111a, the convex curved portion 112a, the concave curved portion 111b, the convex curved portion 112b, and the concave curved portion 111c are arranged in this order, continuously from the +Y side to the -Y side.

[0128] The convex surface 1120 formed by the convex curved portion 112 constitutes a part of the outer surface of the upper wall portion 110. The outer surface of the upper wall portion 110 has two convex surfaces 1120, each formed by the convex curved portions 112a and 112b. The convex surface 1120 extends along the X-axis direction. The convex surface 1120 extends from one end to the other in the X-axis direction of the outer surface of the upper wall portion 110. The concave surface 1110 of the concave curved portion 111a, the convex surface 1120 of the convex curved portion 112a, the concave surface 1110 of the concave curved portion 111b, the convex surface 1120 of the convex curved portion 112b, and the concave surface 1110 of the concave curved portion 111c are arranged in this order, continuously from the +Y side to the -Y side. The outer surface of the upper wall portion 110 is uneven whether viewed from the +X side or the -X side.

[0129] In the upper wall portion 110, the parts other than the multiple concave curved portions 111 and the multiple convex curved portions 112 form, for example, flat portions (in other words, flat plate-like portions). Similarly, the lower wall portion 120 forms, for example, an entirely flat plate-like portion.

[0130] In the example above, the upper wall portion 110 of case 100 has three concave curved portions 111, but it may have one concave curved portion 111, or two concave curved portions 111. Also, the upper wall portion 110 may not have any concave curved portions 111 and may be a flat portion. Furthermore, if a groove-shaped concave surface is provided on at least one of the -Z-side surfaces of the inter-cell portions 26a to 26d, the lower wall portion 120 may have at least one concave curved portion, similar to the upper wall portion 110. Also, even if a groove-shaped concave surface is provided on at least one of the -Z-side surfaces of the inter-cell portions 26a to 26d, the lower wall portion 120 may be a flat portion, as shown in Figure 2.

[0131] Furthermore, in the above example, the portion between the two concave curved portions 111 in the upper wall portion 110 is a convex curved portion 112, but it may also be a flat portion. Also, the portion between the two concave curved portions provided in the lower wall portion 120 may be a convex curved portion or a flat portion.

[0132] As described above, the cover portion 23 of the cell holder 22 has a first opening 230 that exposes at least one outer peripheral surface 210 of the plurality of battery cells 21 when viewed from the +Z side. As a result, when viewed from the +Z side, at least one outer peripheral surface 210 of the plurality of battery cells 21 is not covered by the cell holder 22, which reduces the size of the battery device 10 in the Z-axis direction, in other words, the thickness of the battery device 10. Therefore, the battery device 10 can be made smaller.

[0133] Furthermore, the cover portion 23 of the cell holder 22 has not only the first opening 230, but also a second opening 235 that exposes at least one outer peripheral surface 210 of the multiple battery cells 21 in a plan view from the -Z side. As a result, the size of the battery device 10 in the Z-axis direction can be reduced not only in a plan view from the +Z side, but also in a plan view from the -Z side, because at least one outer peripheral surface 210 of the multiple battery cells 21 is not covered by the cell holder 22.

[0134] Furthermore, in the cell holder 22, as shown in Figure 16, in a cross-sectional view in the direction of cell alignment, the cross-sectional structure of the peripheral edge 238 of the upper opening 231 in the cover portion 23 does not protrude beyond the vertex 211a of the exposed surface 211 that is exposed from the opening 231 on the outer circumferential surface 210 of the battery cell 21. As a result, in a cross-sectional view in the direction of alignment, the size of the battery device 10 in the Z-axis direction can be reduced compared to the case where the cross-sectional structure of the peripheral edge 238 protrudes beyond the vertex 211a of the exposed surface 211 of the battery cell 21.

[0135] Furthermore, in a cross-sectional view in the direction of cell alignment, the cross-sectional structure of the peripheral edge 239 of the lower opening 236 in the cover portion 23 does not protrude beyond the vertex 212a of the exposed surface 212 exposed from the opening 236 on the outer peripheral surface 210 of the battery cell 21. As a result, in a cross-sectional view in the direction of alignment, the size of the battery device 10 in the Z-axis direction can be reduced compared to the case where the cross-sectional structure of the peripheral edge 239 protrudes beyond the vertex 212a of the exposed surface 212 of the battery cell 21.

[0136] Furthermore, in the cell holder 22, as shown in Figure 10, etc., in a plan view from the +Z side, one end 215 in the longitudinal direction of the outer peripheral surface 210 of the battery cell 21 is exposed from the upper opening 231. As a result, in a plan view from the +Z side, the size of the battery device 10 in the Z-axis direction can be reduced compared to the case where the cover portion 23 covers one end 215 in the longitudinal direction of the outer peripheral surface 210 of the battery cell 21.

[0137] Furthermore, in the cell holder 22, as shown in Figure 10, etc., in a plan view from the +Z side, both ends 215 in the longitudinal direction of the outer peripheral surface 210 of the battery cell 21 are exposed from the upper opening 231. As a result, in a plan view from the +Z side, the size of the battery device 10 in the Z-axis direction can be reduced compared to the case where the cover portion 23 covers both ends 215 in the longitudinal direction of the outer peripheral surface 210 of the battery cell 21.

[0138] Furthermore, in the cell holder 22, as shown in Figure 11, etc., in a plan view from the -Z side, one end 215 in the longitudinal direction of the outer peripheral surface 210 of the battery cell 21 is exposed from the lower opening 236. As a result, in a plan view from the -Z side, the size of the battery device 10 in the Z-axis direction can be reduced compared to the case where the cover portion 23 covers one end 215 in the longitudinal direction of the outer peripheral surface 210 of the battery cell 21.

[0139] Furthermore, in the cell holder 22, as shown in Figure 11, etc., in a plan view from the -Z side, both ends 215 in the longitudinal direction of the outer peripheral surface 210 of the battery cell 21 are exposed from the lower opening 236. As a result, in a plan view from the -Z side, the size of the battery device 10 in the Z-axis direction can be reduced compared to the case where the cover portion 23 covers both ends 215 in the longitudinal direction of the outer peripheral surface 210 of the battery cell 21.

[0140] Furthermore, in the cell holder 22, as shown in Figure 17, in a cross-sectional view in the longitudinal direction of the cell, the first portion 238a on the left end 215a side of the cell outer surface 210 in the cross-sectional structure of the upper peripheral edge portion 238 does not protrude beyond the cell outer surface 210. As a result, the size of the battery device 10 in the Z-axis direction can be reduced compared to the case where the first portion 238a protrudes beyond the cell outer surface 210.

[0141] Furthermore, in a longitudinal cross-sectional view of the cell, not only the first portion 238a, but also the second portion 238b on the right end 215b side of the cell outer surface 210 in the cross-sectional structure of the upper peripheral edge portion 238, does not protrude beyond the cell outer surface 210, thus allowing the size of the battery device 10 in the Z-axis direction to be reduced.

[0142] Furthermore, as shown in Figure 17, in a longitudinal cross-sectional view of the cell, the first portion 239a on the left end 215a side of the cell outer surface 210 in the cross-sectional structure of the lower peripheral edge portion 239 does not protrude beyond the cell outer surface 210. This makes it possible to reduce the size of the battery device 10 in the Z-axis direction compared to the case where the first portion 239a protrudes beyond the cell outer surface 210.

[0143] Furthermore, in a cross-sectional view along the longitudinal direction of the cell, not only the first portion 239a, but also the second portion 239b on the right end 215b side of the cell outer surface 210 in the cross-sectional structure of the lower peripheral edge portion 239, does not protrude beyond the cell outer surface 210, thus allowing the size of the battery device 10 in the Z-axis direction to be reduced.

[0144] Furthermore, in the cell holder 22, the surface visible in a plan view from the +Z side in the inter-cell portion 26 has a groove-shaped concave surface 265 that extends along the longitudinal direction of the cell and has open ends, thus making the cell holder 22 lighter.

[0145] Furthermore, since the inter-cell portion 26 has an opening 260 that exposes the outer circumferential surfaces 210 of the two battery cells 21 that sandwich the inter-cell portion 26, the cell holder 22 can be made lighter.

[0146] Furthermore, in the cell holder 22, the first part holder 2200 and the second part holder 2250 can be easily attached to each other by engaging the engaging claws and engaging holes included in the mounting structure 220. In addition, the battery device 10 can be made smaller compared to the case where screws or the like are used instead of the pair of engaging claws and engaging holes included in the mounting structure 220.

[0147] Furthermore, since the engaging claws and engaging holes included in the mounting structure 220 are located between two adjacent battery cells 21, the size of the battery device 10 in the Z-axis direction can be reduced compared to the case where the engaging claws and engaging holes are located on the +Z side or -Z side of the battery cell 21.

[0148] Furthermore, as shown in Figures 1 and 16, the case 100 has a concave curved portion 111 that is recessed along a groove-shaped concave surface 265 provided on the +Z side surface of the inter-cell portion 26. This makes the case 100 less likely to slip when a user holds it in their hand. In addition, if the case 100 has a convex curved portion 112 in addition to the concave curved portion 111, the case 100 becomes even less likely to slip.

[0149] <Example of circuit board layout> As shown in Figures 5 and 6, circuit boards 30 and 40 are positioned on the -Y side relative to the battery pack 20. Circuit board 30 is located closer to the battery pack 20 than circuit board 40. The multiple battery cells 21, circuit boards 30 and 40 are aligned along the Y-axis.

[0150] The wiring board 31 of circuit board 30 and the wiring board 41 of circuit board 40 are, for example, rectangular plates that extend along the X-axis. The wiring boards 31 and 41 spread along the XZ plane. Circuit boards 30 and 40 are erected along the Z-axis and X-axis directions. In other words, circuit boards 30 and 40 are erected in directions perpendicular to the cell alignment direction and the cell longitudinal direction, and along the cell longitudinal direction. Circuit boards 30 and 40 are arranged facing each other.

[0151] Circuit boards 30 and 40 are electrically connected to each other by a plurality of connecting members 70. The connecting members 70 are, for example, pin headers having a plurality of pins. The plurality of pins on the connecting members 70 are soldered, for example, to the wiring board 31 of circuit board 30 and the wiring board 41 of circuit board 40. The distance between circuit boards 30 and 40 is maintained by the plurality of connecting members 70. The wiring on wiring board 31 and wiring board 41 are electrically connected to each other by the connecting members 70. By electrically connecting circuit boards 30 and 40 to each other, it becomes possible to exchange signals and the like between circuit boards 30 and 40.

[0152] On circuit board 40, an operation button 43 is mounted on the -Y side of the wiring board 41. The area of ​​the operation button 43 that is pressed by the user is exposed from the -Y side outer surface of the side wall portion 130 of the case 100, as shown in Figure 1, etc. On circuit board 30, a connector 34 is mounted on the -Y side of the wiring board 31. The distance between wiring board 41 and wiring board 31 is approximately the same as the height of the connector 34. Note that in Figures 5 and 6, the illustration of components other than the connector 34 among the multiple components of circuit board 30 is omitted. Also, in Figures 5 and 6, the illustration of components other than the operation button 43 among the multiple components of circuit board 40 is omitted.

[0153] <Example of thermistor placement> As shown in Figures 6 and 16, the body 81 of the thermistor 80 (also called the thermistor body 81) is located, for example, between the cell holder 22 and the final stage battery cell 21e. As shown in Figures 14, 16, and 18, the inner surface (in other words, the +Y side) of the lower cover portion 278 of the cell holder 22 is provided with an arrangement groove 278z in which the thermistor body 81 is positioned. The arrangement groove 278z extends along the X-axis direction.

[0154] As shown in Figure 6, two lead wires 82 extend from the thermistor body 81, which is positioned within the placement groove 278z. The lead wires 82 pass through the placement groove 278z and extend along the battery cell 21e towards the -X side. Then, near the -X end of the battery cell 21e, the lead wires 82 bend towards the -Y side and reach the circuit board 40. The two lead wires 82 are electrically connected to the wiring board 41.

[0155] <Example of wiring component configuration> The wiring member 50 is, for example, a sheet-like member, and is made of, for example, an FPC (Flexible Printed Circuit). An FPC is called a flexible circuit board or flexible wiring board. The wiring member 50 is bent into a U shape (in other words, into the shape of the Japanese katakana character "コ"). The wiring member 50 is U-shaped when viewed from the +Z side or the -Z side. As shown in Figures 5 and 6, the wiring member 50 includes a first wiring section 51 facing the first end face cover section 24 of the cell holder 22, a second wiring section 52 facing the second end face cover section 25 of the cell holder 22, and a third wiring section 53 connecting the first wiring section 51 and the second wiring section 52.

[0156] The sheet-like first wiring section 51 is located on the +X side of the battery pack 20 and extends along the YZ plane. The first wiring section 51 is erected along the Y-axis and Z-axis directions. The connecting projections 280 of the connecting conductive plates 28a and 28c of the battery pack 20 and the connecting projection 290 of the connecting conductive plate 29b are soldered to the first wiring section 51, for example, while penetrating it. The cell holder 22 has a plurality of positioning projections 2800 for positioning the first wiring section 51. In this example, two positioning projections 2800 are provided on the cell holder 22. As shown in Figure 9, the two positioning projections 2800 protrude to the +X side from, for example, the +X side end faces of the inter-cell portions 26b and 26d, respectively. Each positioning projection 2800 protrudes from the cell holder 22 toward the first wiring section 51 and penetrates the first wiring section 51.

[0157] The sheet-like second wiring section 52 is located on the -X side of the battery pack 20 and extends along the YZ plane. The second wiring section 52 faces the first wiring section 51 with the battery pack 20 in between. The connecting projections 280 on the connecting conductive plates 28b and 28d and the connecting projection 290 on the connecting conductive plate 29a of the battery pack 20 are soldered to the second wiring section 52, for example, while penetrating it. The cell holder 22 has a plurality of positioning projections 2810 for positioning the second wiring section 52. In this example, two positioning projections 2810 are provided on the cell holder 22. As shown in Figure 8, the two positioning projections 2810 protrude to the -X side from, for example, the -X side end faces of the inter-cell portions 26a and 26c, respectively. Each positioning projection 2810 protrudes from the cell holder 22 toward the second wiring section 52 and penetrates the second wiring section 52.

[0158] The sheet-like third wiring section 53 is located on the -Y side of the battery pack 20 and extends along the XZ plane. The third wiring section 53 is approximately perpendicular to the first wiring section 51 and the second wiring section 52. The third wiring section 53 is electrically connected to the circuit board 30 by a connecting member 60. The connecting member 60 is, for example, a pin header having multiple pins, and is surface-mounted on the -Y side surface of the third wiring section 53. The multiple pins of the connecting member 60 protrude in the -Y direction and penetrate the wiring board 31 of the circuit board 30. The multiple pins of the connecting member 60 are, for example, soldered to the wiring board 31. As shown in Figure 6, insulating paper 90 is placed between the third wiring section 53 and the final stage battery cell 21e. Even if the coating on the outer surface 210 of the battery cell 21e is damaged, the electrical insulation between the battery cell 21e and the third wiring section 53 is maintained by the insulating paper 90.

[0159] The wiring member 50 comprises, for example, a base material made of resin or the like, a plurality of wires on the base material, and a coverlay made of resin or the like that covers the plurality of wires. Figures 22 and 23 are schematic diagrams showing an example of the arrangement relationship between the plurality of wires of the wiring member 50 and the plurality of battery cells 21. In Figures 22 and 23, for the sake of explanation, only the plurality of wires are shown extracted from the wiring member 50.

[0160] The wiring member 50 comprises, for example, a plurality of wires 511-513, 521-523, and 531-536. Each of the plurality of wires 511-513, 521-523, and 531-536 is made of, for example, a metal such as copper. Wires 511-513 are provided in the first wiring section 51, wires 521-523 are provided in the second wiring section 52, and wires 531-536 are provided in the third wiring section 53.

[0161] The connecting protrusions 280 of connecting conductive plates 28a and 28c and the connecting protrusion 290 of connecting conductive plate 29a are soldered to the first wiring section 51, thereby electrically connecting the wires 511 to 513 to the connecting conductive plates 28a, 28c, and 29b, respectively. Wire 511 is electrically connected to the +X side terminal (i.e., positive terminal) of battery cell 21a and the +X side terminal (i.e., negative terminal) of battery cell 21b through connecting conductive plate 28a. Wire 512 is electrically connected to the +X side terminal (i.e., positive terminal) of battery cell 21c and the +X side terminal (i.e., negative terminal) of battery cell 21d through connecting conductive plate 28c. Wire 513 is electrically connected to the +X side terminal (i.e., positive terminal) of battery cell 21e through connecting conductive plate 29b. The width of wire 513, which carries a relatively large current, is set to be larger than the width of wires 511 and 512.

[0162] Wires 511-513 are located on one side of the cell longitudinal direction relative to the multiple battery cells 21. More specifically, wires 511-513 are located on the +X side relative to the multiple battery cells 21. Wires 511-513 extend generally along the Y axis. Wire 511 faces the +X side end faces of battery cells 21a-21e. Wire 512 faces the +X side end faces of battery cells 21d and 21e. Wire 513 faces the +X side end face of battery cell 21e.

[0163] The connecting projections 290 of the connecting conductive plate 29a and the connecting projections 280 of the connecting conductive plates 28b and 28d are soldered to the second wiring section 52, thereby electrically connecting the wires 521 to 523 to the connecting conductive plates 29a, 28b, and 28d, respectively. Wire 521 is electrically connected to the -X side terminal (i.e., the negative terminal) of the battery cell 21a via the connecting conductive plate 29a. Wire 522 is electrically connected to the -X side terminal (i.e., the positive terminal) of the battery cell 21b and the -X side terminal (i.e., the negative terminal) of the battery cell 21c via the connecting conductive plate 28b. Wire 523 is electrically connected to the -X side terminal (i.e., the positive terminal) of the battery cell 21d and the -X side terminal (i.e., the negative terminal) of the battery cell 21e via the connecting conductive plate 28d. The width of wire 521, which carries a relatively large current, is set to be larger than the widths of wires 522 and 523.

[0164] Wirings 521 to 523 are located on the other side of the cell longitudinal direction relative to the multiple battery cells 21. More specifically, wirings 521 to 523 are located on the -X side relative to the multiple battery cells 21. Wirings 521 to 523 extend generally along the Y axis. Wiring 521 faces the -X side end faces of battery cells 21a to 21e. Wiring 522 faces the -X side end faces of battery cells 21c to 21e. Wiring 523 faces the -X side end face of battery cell 21e.

[0165] Wires 531-536 are located on one side of the cell arrangement direction relative to the multiple battery cells 21. Specifically, wires 531-536 are located on the -Y side relative to the multiple battery cells 21. Wires 531-533 are connected to wires 521-523, respectively, and wires 534-536 are connected to wires 511-513, respectively.

[0166] Wire 531 extends in the +X direction from the -Y end of wire 521 and reaches near the +X end of the battery cell 21e. Wire 532 extends in the +X direction from the -Y end of wire 522 and reaches near the +X end of the battery cell 21e. Wire 533 extends in the +X direction from the -Y end of wire 523 and reaches near the +X end of the battery cell 21e. Wires 534-535 are connected to the -Y ends of wires 511-513 and are located near the +X end of the battery cell 21e. The connecting member 60 is provided at the +X end of the third wiring section 53. Multiple pins on the connecting member 60 are electrically connected to the +X ends of wires 531-533 and to wires 534-535, respectively. Wires 531-536 are electrically connected to the wiring board 31 of the circuit board 30 through the connecting member 60.

[0167] The potential V0 of the negative terminal of battery cell 21a is input to the circuit board 30 through the connecting conductive plate 29a, the wiring 521 and 531, and the connecting member 60. The potential V1 of the positive terminal of battery cell 21a is input to the circuit board 30 through the connecting conductive plate 28a, the wiring 511 and 534, and the connecting member 60. The potential V2 of the positive terminal of battery cell 21b is input to the circuit board 30 through the connecting conductive plate 28b, the wiring 522 and 532, and the connecting member 60. The potential V3 of the positive terminal of battery cell 21c is input to the circuit board 30 through the connecting conductive plate 28c, the wiring 512 and 535, and the connecting member 60. The potential V4 of the positive terminal of battery cell 21d is input to the circuit board 30 through the connecting conductive plate 28d, the wiring 523 and 533, and the connecting member 60. The potential V5 of the positive terminal of the battery cell 21e is input to the circuit board 30 through the connecting conductive plate 29b, the wiring 513 and 536, and the connecting member 60.

[0168] Note that the wiring 511-513, 521-523, and 531-536 were wiring provided by the FPC, but they may also be composed of busbars. In this case, the wiring member 50 consists only of the busbar wiring 511-513, 521-523, and 531-536. Even in this case, the wiring member 50 as a whole is U-shaped when viewed from the +Z or -Z side in plan view. A busbar is a plate-shaped member, made of a metal such as copper or aluminum. Hereafter, the wiring 511-513, 521-523, and 531-536 composed of busbars will be referred to as busbar wiring 511-513, 521-523, and 531-536.

[0169] One end of each busbar wire 511, 512, and 513 is soldered to, for example, the connecting projection 280 of the connecting conductive plate 28a, the connecting projection 280 of the connecting conductive plate 28c, and the connecting projection 290 of the connecting conductive plate 29a. One end of each busbar wire 521, 522, and 523 is soldered to, for example, the connecting projection 290 of the connecting conductive plate 29a, the connecting projection 280 of the connecting conductive plate 28b, and the connecting projection 280 of the connecting conductive plate 28d. The multiple pins provided on the connecting member 60 are soldered to the busbar wires 531 to 536, respectively.

[0170] Thus, in the battery device 10, the wirings 511 to 513 are located on one side in the longitudinal direction of the multiple battery cells 21. This makes it possible to reduce the size of the battery device 10 in the Z-axis direction, or in other words, the thickness of the battery device 10, compared to the case where the wirings 511 to 513 are located on the +Z side or the -Z side of the multiple battery cells 21.

[0171] Furthermore, in the battery device 10, since the wiring 521 to 523 is located on the other side in the longitudinal direction of the cell relative to the multiple battery cells 21, the size of the battery device 10 in the Z-axis direction can be reduced.

[0172] Furthermore, since the wirings 531 to 536 are located on one side of the cell alignment direction relative to the multiple battery cells 21, the size of the battery device 10 in the Z-axis direction can be reduced compared to the case where the wirings 531 to 536 are located on the +Z side or -Z side relative to the multiple battery cells 21.

[0173] Furthermore, since the circuit board 30 to which the wires 531-536 are electrically connected is located on the same side as the wires 531-536 with respect to the multiple battery cells 21, it becomes easier to electrically connect the circuit board 30 to the wires 531-536.

[0174] Furthermore, the circuit board 30 is erected vertically and along the longitudinal direction of the cells, perpendicular to the cell arrangement direction and the longitudinal direction of the cells. In other words, the circuit board 30 is erected along the XZ plane. This makes it possible to reduce the size of the battery device 10 in the Y-axis direction (in other words, the size in the front-to-back direction) compared to the case where the circuit board 30 is arranged parallel to, for example, the XY plane.

[0175] Furthermore, since the circuit board 40 is erected vertically and along the longitudinal direction of the cells, perpendicular to the cell arrangement direction and the longitudinal direction of the cells, the size of the battery device 10 in the Y-axis direction can be reduced.

[0176] Furthermore, since circuit board 30 is located closer to wiring 531-536 than circuit board 40, it becomes easier to electrically connect circuit board 30 and wiring 531-536.

[0177] The placement of the wiring member 50, circuit board 30, circuit board 40, and thermistor 80 is not limited to the above example. For example, the wiring member 50 may have a portion located above the battery pack 20, a portion located below the battery pack 20, or a portion located on the +Y side of the battery pack 20. Also, at least one of the circuit boards 30 and 40 may be located above the battery pack 20, below the battery pack 20, or on the +Y side of the battery pack 20. Furthermore, at least one of the circuit boards 30 and 40 may be arranged parallel to the XY plane, parallel to the YZ plane, or in any other orientation. In addition, the body 81 of the thermistor 80 may be located near one of the battery cells 21a to 21d, rather than near the battery cell 21e.

[0178] <Other configuration examples for cell holders> In the above example, all of the multiple engagement holes in the mounting structure 220 that attaches the first part holder 2200 and the second part holder 2250 to each other are provided on the first part holder 2200, and all of the multiple engagement claws provided on the mounting structure 220 are provided on the second part holder 2250. However, the first part holder 2200 and the second part holder 2250 may each have engagement holes and engagement claws. Figures 24 and 25 are schematic perspective views showing an example of the configuration of the cell holder 22 (also called cell holder 22A) in this case. Below, the configuration of the cell holder 22A will be explained, focusing on the differences from the cell holder 22 shown in Figures 14, 15, 18, 19, etc.

[0179] The first part holder 2200 (also referred to as the first part holder 2200A) of the cell holder 22A comprises, for example, two perforated portions 2210A having engagement holes and two clawed portions 2260A having engagement claws. Similarly, the second part holder 2250 (also referred to as the second part holder 2250A) of the cell holder 22A comprises, for example, two perforated portions 2210A and two clawed portions 2260A. The perforated portion 2210A has the same structure as the first inter-cell portion 2210 described above. The clawed portion 2260A has the same structure as the second inter-cell portion 2260 described above.

[0180] The perforated portion 2210A has an upper portion 2220A, a lower portion 2230A, and a connecting portion 2240A that connects the upper portion 2220A and the lower portion 2230A to each other. The upper portion 2220A has the same structure as the upper portion 2220 described above. The lower portion 2230A has the same structure as the lower portion 2230 described above, except that it does not have a guide projection 2232. The connecting portion 2240A is the same as the connecting portion 2240 described above. The lower portion 2230A may be provided with a guide projection 2232.

[0181] The clawed portion 2260A has an upper portion 2270A, a lower portion 2280A, and a connecting portion 2290A that connects the upper portion 2270A and the lower portion 2280A to each other. The upper portion 2270A has the same structure as the upper portion 2270 described above. The lower portion 2280A has the same structure as the lower portion 2280 described above, except that it does not have a guide groove 2282. The connecting portion 2290A is the same as the connecting portion 2290 described above. The lower portion 2280A may be provided with a guide groove 2282.

[0182] In the first part holder 2200A, one perforated portion 2210A, one clawed portion 2260A, the other perforated portion 2210A, and the other clawed portion 2260A are arranged in this order from the +Y side to the -Y side. As a result, in the first part holder 2200A, the engagement hole 2221 (also called the upper left first engagement hole 2221) of the upper part 2220A of one of the perforated parts 2210A, the engagement claw 2271 (also called the upper left first engagement claw 2271) of the upper part 2270A of one of the clawed parts 2260A, the engagement hole 2221 (also called the upper left second engagement hole 2221) of the upper part 2220A of the other perforated part 2210A, and the engagement claw 2271 (also called the upper left second engagement claw 2271) of the upper part 2270A of the other clawed part 2260A are arranged in this order from the +Y side to the -Y side. Furthermore, in the first part holder 2200A, the engagement hole 2231 (also called the lower left first engagement hole 2231) of the lower part 2230A of one of the perforated parts 2210A, the engagement claw 2281 (also called the lower left first engagement claw 2281) of the lower part 2280A of one of the clawed parts 2260A, the engagement hole 2231 (also called the lower left second engagement hole 2231) of the lower part 2230A of the other perforated part 2210A, and the engagement claw 2281 (also called the lower left second engagement claw 2281) of the lower part 2280A of the other clawed part 2260A are arranged in this order from the +Y side to the -Y side.

[0183] In the second part holder 2250A, one clawed portion 2260A, one perforated portion 2210A, the other clawed portion 2260A, and the other perforated portion 2210A are arranged in this order from the +Y side to the -Y side. As a result, in the second part holder 2250A, the engaging claw 2271 (also called the upper right first engaging claw 2271) of the upper part 2270A of one of the clawed parts 2260A, the engaging hole 2221 (also called the upper right first engaging hole 2221) of the upper part 2220A of one of the perforated parts 2210A, the engaging claw 2271 (also called the upper right second engaging claw 2271) of the upper part 2270A of the other clawed part 2260A, and the engaging hole 2221 (also called the upper right second engaging hole 2221) of the upper part 2220A of the other perforated part 2210A are arranged in this order from the +Y side to the -Y side. Furthermore, in the second part holder 2250A, the engaging claw 2281 (also called the lower right first engaging claw 2281) of the lower part 2280A of one of the clawed parts 2260A, the engaging hole 2231 (also called the lower right first engaging hole 2231) of the lower part 2230A of one of the perforated parts 2210A, the engaging claw 2281 (also called the lower right second engaging claw 2281) of the lower part 2280A of the other clawed part 2260A, and the engaging hole 2231 (also called the lower right second engaging hole 2231) of the lower part 2230A of the other perforated part 2210A are arranged in this order from the +Y side to the -Y side.

[0184] In cell holder 22A, on the +Z side, the upper left first engagement hole 2221, upper left first engagement claw 2271, upper left second engagement hole 2221 and upper left second engagement claw 2271 engage with the upper right first engagement claw 2271, upper right first engagement hole 2221, upper right second engagement claw 2271 and upper right second engagement hole 2221, respectively. In both the first partial holder 2200A and the second partial holder 2250A, engagement holes 2221 and engagement claws 2271 are alternately provided along the Y axis.

[0185] Furthermore, in the cell holder 22A, on the -Z side, the lower left first engagement hole 2231, lower left first engagement claw 2281, lower left second engagement hole 2231 and lower left second engagement claw 2281 engage with the lower right first engagement claw 2281, lower right first engagement hole 2231, lower right second engagement claw 2281 and lower right second engagement hole 2231, respectively. In the first partial holder 2200A and the second partial holder 2250A, engagement holes 2231 and engagement claws 2281 are alternately provided along the Y axis.

[0186] A single inter-cell portion 26 is formed by connecting the upper portion 2220A and lower portion 2230A of the perforated portion 2210A of the first part holder 2200A with the upper portion 2270A and lower portion 2280A of the clawed portion 2260A of the second part holder 2250A. Additionally, a single inter-cell portion 26 is formed by connecting the upper portion 2270A and lower portion 2280A of the clawed portion 2260A of the first part holder 2200A with the upper portion 2220A and lower portion 2230A of the perforated portion 2210A of the second part holder 2250A.

[0187] The opening 245 (also called opening 245A) provided in the first end face cover portion 24 of the cell holder 22A has openings 246 to 248 instead of openings 240 to 242. Opening 246 exposes the connecting conductive plate 28a. Opening 247 exposes the connecting conductive plate 28c. Opening 248 exposes the connecting conductive plate 29b.

[0188] The opening 255 (also called opening 255A) provided in the second end face cover portion 25 of the cell holder 22A has openings 256 to 258 instead of openings 250 to 252. Opening 256 exposes the connecting conductive plate 29a. Opening 257 exposes the connecting conductive plate 28b. Opening 258 exposes the connecting conductive plate 28d.

[0189] The cell holder 22A has one positioning projection 2800 and one positioning projection 2810. In the cell holder 22A, the positioning projection 2800 protrudes from the +X side end face of the inter-cell portion 26c toward the +X side, for example, and the positioning projection 2810 protrudes from the -X side end face of the inter-cell portion 26b toward the -X side.

[0190] The structure of the cell holder 22 is not limited to the example described above. For example, in each of the first part holder 2200 and the second part holder 2250, multiple engagement holes and multiple engagement claws may be arranged in a continuous line along the Y-axis.

[0191] In the example above, the lower cover portion 278 near the thermistor body 81 is curved along the outer surface 210 of the battery cell 21e, but it does not have to be curved. Figure 26 is a schematic diagram showing an example of the cross-sectional structure of the case 100, cell holder 22, and multiple battery cells 21 in this case. Figure 26 corresponds to Figure 16 described above.

[0192] In the example shown in Figure 26, the lower cover portion 278 is bent at a right angle from the Y-axis direction to the Z-axis direction, for example, and consists of a flat portion 278a parallel to the XY plane and a flat portion 278b parallel to the XZ plane. The -Y side end of the flat portion 278a and the -Z side end of the flat portion 278b are connected. The angle between the flat portion 278a and the flat portion 278b is, for example, 90 degrees.

[0193] The inner surface of the lower cover portion 278 (in other words, the surface facing the battery cell 21e) is not curved along the outer surface 210 of the battery cell 21e. The inner surface of the lower cover portion 278 is composed of a flat surface parallel to the XY plane (the inner surface of the flat portion 278a) and a flat surface parallel to the XZ plane (the inner surface of the flat portion 278b). The inner flat surface of the flat portion 278a and the inner flat surface of the flat portion 278b form, for example, a 90-degree angle. That is, the angle formed by the inner flat surface of the flat portion 278a and the inner flat surface of the flat portion 278b is, for example, 90°. The thermistor body 81 is positioned in the space formed by the inner flat surface of the flat portion 278a, the inner flat surface of the flat portion 278b, and the outer surface 210 of the battery cell 21e.

[0194] In this way, by making the inner surface of the lower cover portion 278 a flat surface, it becomes easier to secure space for the thermistor body 81. As a result, it becomes easier to position the thermistor body 81.

[0195] Furthermore, the angle between the flat portion 278a and the flat portion 278b may be greater than 90 degrees or less than 90 degrees. In other words, the angle between the inner flat surface of the flat portion 278a and the inner flat surface of the flat portion 278b may be greater than 90 degrees or less than 90 degrees.

[0196] As described above, the cell holder and battery device have been described in detail, but the above description is illustrative in all respects, and this disclosure is not limited thereto. Furthermore, the various modifications described above can be applied in combination as long as they do not contradict each other. And it is understood that countless modifications not illustrated can be conceivable without falling outside the scope of this disclosure. [Explanation of symbols]

[0197] 10 Battery device 21, 21a, 21b, 21c, 21d, 21e battery cells 22 Cell holder 23 Cover section 26,26a,26b,26c,26d Part between cells 30 Power supply circuit board 33 Power supply section 40 Control circuit board 100 cases 111,111a,111b,111c Concave curved part 210 Outer surface 211,212 Exposed surface Vertices 211a, 212a 215 edge 215a Left edge 215b Right end 220 Mounting structure 230, 235, 260 openings 231,231a,231b,231c,231d,231e,236,236a,236b,236c,236d,236e opening 238,239 Peripheral area 238a,239a Part 1 238b,239b 2nd part 265 Groove-like concave surface Wiring for 511-513, 521-523, 531-536 2200, 2200A First Part Holder 2250, 2250A Second part holder 2221,2231 Engagement holes 2271,2281 Engaging claws

Claims

1. A cell holder that holds a plurality of cylindrical battery cells connected in series such that the plurality of battery cells are arranged in a line along a direction perpendicular to the longitudinal direction of the plurality of battery cells, A cover portion is formed to cover the surface of the plurality of battery cells, and has a first partial holder and a second partial holder that sandwich the plurality of battery cells from the longitudinal direction, The cover portion has a first opening that exposes at least one outer surface of the plurality of battery cells in a first plan view from one side in a vertical direction perpendicular to the direction in which the plurality of battery cells are arranged and the longitudinal direction, The cover portion has an intercell portion that is sandwiched between two adjacent battery cells within the plurality of battery cells, The portion between the aforementioned cells is, Sandwiched between the two battery cells, the inter-cell first portion included in the first portion holder, The inter-cell first portion is connected to the inter-cell second portion which is sandwiched between the two battery cells and included in the second portion holder. It has, The first portion between the cells is, A first portion located between the two battery cells and extending from the first location toward the second portion between the cells, The first portion has an engagement hole that penetrates vertically and It has, The second portion between the cells has an engaging claw that engages with the engaging hole from the inside of the cell holder, The engagement hole and the engagement claw are located between the two battery cells in the cell holder.

2. A cell holder according to claim 1, The first part is a cell holder having a concave surface through which the engagement hole opens.

3. A cell holder according to claim 1, The second inter-cell portion is located between the two battery cells and has a second portion provided with the engaging claws that extends from the second location toward the first inter-cell portion. The second portion in the intercellular second portion has a second front end surface that faces the first portion in the intercellular first portion in the longitudinal direction. The first portion in the inter-cell first portion is a cell holder having a first opposing surface that faces the second tip surface.

4. A cell holder according to any one of claims 1 to 3, The second inter-cell portion is located between the two battery cells and has a second portion that extends from the second location toward the first inter-cell portion. The first portion in the intercellular first portion has a first tip surface that faces the second portion in the intercellular second portion in the longitudinal direction, The second portion in the second portion between cells is A second opposing surface facing the first tip surface, A first surface extending from the second opposing surface toward the first portion in the first portion between cells in the longitudinal direction, It has, The aforementioned engaging claw is provided on the first surface of the cell holder.

5. A cell holder according to any one of Claims 1 to 4, The first portion of the first inter-cell portion has a first recess that is located on the first side of the engagement hole and opens toward the outside of the cell holder, The cell holder has an inner wall surface of the first recess that faces the first location.

6. A cell holder according to claim 5, The cell holder wherein the inner wall surface of the first recess has a second wall surface facing the first wall surface.

7. A cell holder according to any one of claims 1 to 6, The second inter-cell portion is located between the two battery cells and has a second portion provided with the engaging claws that extends from the second location toward the first inter-cell portion. The second portion of the inter-cell second portion has a second recess that is located on the second side of the engaging claw and opens toward the outside of the cell holder, The cell holder has an inner wall surface of the second recess having a third wall surface facing the second location.

8. A cell holder according to claim 7, The cell holder wherein the inner wall surface of the second recess has a fourth wall surface that faces the third wall surface.

9. A cell holder according to any one of claims 1 to 8, The cover portion is a cell holder having a second opening that exposes at least one of the outer circumferential surfaces of the plurality of battery cells in a second plan view from the other side in the vertical direction.

10. A cell holder according to any one of claims 1 to 9, The first opening includes an opening that, in the first plan view, exposes the outer circumferential surface of a battery cell included in the plurality of battery cells, In a first cross-sectional view in a plane perpendicular to the longitudinal direction, the cross-sectional structure of the peripheral edge of the opening in the cover portion does not protrude beyond the vertex of the exposed surface exposed from the opening on the outer surface of a certain battery cell, in the cell holder.

11. A cell holder according to any one of claims 1 to 9, The first opening includes an opening that, in the first plan view, exposes the outer circumferential surface of a battery cell included in the plurality of battery cells, In the first plan view, one end of the outer surface of a certain battery cell in the longitudinal direction is exposed through the opening, a cell holder.

12. A cell holder according to claim 11, In the first plan view, one end and the other end of the outer surface of a certain battery cell in the longitudinal direction are exposed through the opening, a cell holder.

13. A cell holder according to claim 11 or claim 12, A cell holder in which, in a second cross-sectional view in a plane perpendicular to the direction of alignment and passing through the central axis of a certain battery cell, the first portion on one end of the cross-sectional structure of the peripheral edge of the opening in the cover portion does not protrude beyond the outer surface of the certain battery cell.

14. A cell holder according to claim 12, A cell holder in which, in a second cross-sectional view in a plane perpendicular to the direction of alignment and passing through the central axis of a certain battery cell, the first portion on one end and the second portion on the other end of the cross-sectional structure of the peripheral edge of the opening in the cover portion do not protrude beyond the outer surface of the certain battery cell.

15. A cell holder according to any one of claims 1 to 14, The cell holder has a groove-shaped concave surface extending along the longitudinal direction and open at both ends, which is visible in the first plan view of the inter-cell portion.

16. A cell holder according to claim 15, The cell holder has a third opening that exposes the outer surfaces of the two battery cells in the inter-cell portion.

17. A cell holder according to any one of claims 1 to 16, The first part holder and the second part holder are provided with a mounting structure for attaching them to each other. The mounting structure has a plurality of engaging claws, including the engaging claws, that are located in the second inter-cell portion, and a plurality of engaging holes, including the engaging holes, that engage with each of the plurality of engaging claws, that are located in the first inter-cell portion. A cell holder in which, in each of the first and second portion holders, the engaging claws and engaging holes of the mounting structure are alternately provided along the direction of alignment.

18. A cell holder according to any one of claims 1 to 17, The plurality of battery cells held by the cell holder and A battery device equipped with the following features.

19. A battery device according to claim 18, The cell holder according to claim 15, The cell holder and the case for housing the plurality of battery cells Equipped with, The case has a concave curved portion that is recessed along the groove-shaped concave surface of the inter-cell portion of the cell holder, which is a battery device.

20. A battery device according to claim 19, The battery device has a case having a concave curved portion that is recessed along the groove-shaped concave surface of the inter-cell portion, and a convex curved portion that is convex along the outer circumferential surface of one of the two battery cells that sandwich the inter-cell portion.

21. A battery device according to any one of claims 18 to 20, A battery device further comprising a first wiring that is electrically connected to the terminals of a first battery cell included in the plurality of battery cells and is located on one side in the longitudinal direction relative to the plurality of battery cells.

22. A battery device according to claim 21, A battery device further comprising a second wiring that is electrically connected to the terminals of a second battery cell included in the plurality of battery cells and is located on the other side in the longitudinal direction relative to the plurality of battery cells.

23. A battery device according to claim 22, A battery device further comprising a third wiring connected to the first wiring and located on one side of the arrangement direction relative to the plurality of battery cells.

24. A battery device according to claim 23, A wiring member comprising the first wiring, the second wiring, and the third wiring, A battery device in which the wiring member is U-shaped in the first plan view.

25. A battery device according to claim 23 or claim 24, A battery device further comprising a first circuit board located on one side of the arrangement direction relative to the plurality of battery cells, to which the third wiring is electrically connected.

26. A battery device according to claim 25, The first circuit board is erected along the vertical and longitudinal directions, and is a battery device.

27. A battery device according to claim 26, The system further comprises a second circuit board facing the first circuit board, The first circuit board is located on the third wiring side of the second circuit board, and is a battery device.

28. A battery device according to claim 27, The first circuit board is a power supply circuit board that generates a voltage based on the total voltage of the plurality of battery cells connected in series, The second circuit board is a control circuit board that controls the first circuit board, and is a battery device.

29. A battery device according to any one of claims 18 to 28, A battery device comprising a power supply unit that steps down the total voltage of the multiple battery cells connected in series and outputs it.

30. A battery device according to claim 29, The power supply unit is a battery device that boosts the total voltage and outputs it.

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