Monitoring device

Abstract

A monitoring device includes: a monitoring part that monitors the voltage of each battery cell connected in series, each battery cell having an electrode terminal; and a wiring part that connects the monitoring part to the electrode terminal. The wiring part includes a first flexible substrate and a second flexible substrate, the first flexible substrate and the second flexible substrate are flexible and connected to each other integrally. The connection part where the first flexible substrate and the second flexible substrate are connected is bent. The first flexible substrate is connected to the electrode terminal. The second flexible substrate is connected to the monitoring part. One of the first flexible substrate and the second flexible substrate has an arm. The other of the first flexible substrate and the second flexible substrate, except the one having the arm, has a slit. The arm is fixed to the slit so that the connection part is strengthened.

Description

Technical Field

[0001] The present disclosure relates to a battery cell monitoring device. Background Art

[0002] Patent Document 1 discloses a wiring material for connecting a plurality of battery cells to a control substrate.

[0003] Patent Document 2 shows a battery junction module that detects the voltage of a plurality of unit cells. The battery junction module has a bus bar that connects electrodes of different battery cells to each other and a flexible substrate that has a voltage detection line connected to the bus bar.

[0004] Patent Document 1: JP 2015-118731 A

[0005] Patent Document 2: JP 2017-118731 A

[0006] The wiring material described in Patent Document 1 is connected to the electrodes of the plurality of battery cells. Therefore, the wiring material is placed on the surface of the plurality of battery cells. The electrodes of the plurality of battery cells are formed on the surface (also referred to as a formation surface).

[0007] The wiring material is connected not only to the electrodes of the battery cell but also to the control substrate. When the forming surface does not have a space for the control substrate to be arranged, the control substrate is placed on a surface of the battery cell different from the forming surface.

[0008] A portion of the wiring material is also placed on a surface different from the forming surface. As a result, the wiring material is placed on each of the forming surface and the surface different from the forming surface. In order to achieve the above-mentioned structure, for example, a portion of the wiring material is bent. In addition, a structure in which the wiring material and the control substrate overlap on the control substrate can also be considered. In order to achieve this structure, a portion of the wiring material is also bent.

[0009] In a mode in which the wiring material is bent, stress concentration occurs in the bent portion, and thus the life of the wiring material may be deteriorated.

[0010] When current flows in the bus bar, a voltage drop occurs due to the resistance of the bus bar and the current flowing in the bus bar. As described above, the voltage detection line is connected to the bus bar. Therefore, the voltage detected in the voltage detection line has a voltage drop caused by the resistance of the bus bar and the current flowing in the bus bar.

[0011] When the connection positions on the multiple bus bars to which the voltage detection line is connected are the same for each of the multiple bus bars, the voltage drop of the voltage detected in each of the multiple voltage detection lines may be equal. However, when the connection positions on the multiple bus bars to which the voltage detection line is connected are different for the multiple bus bars, the voltage drop of the voltage detected in the multiple voltage detection lines may vary. These changes in the voltage drop may result in changes in the detection accuracy of the voltage detected in the multiple voltage detection lines (wiring patterns). Summary of the invention

[0012] An object of the present disclosure is to provide a monitoring device that prevents the life of a wiring portion from being deteriorated.

[0013] Another object of the present disclosure is to provide a monitoring device that prevents a variation in detection accuracy of voltages detected in a plurality of wiring patterns.

[0014] According to one aspect of the present disclosure, a monitoring device has: a monitoring part that monitors the voltage of each of a plurality of battery cells connected in series, each battery cell having an electrode terminal; and a wiring part that electrically connects the monitoring part and the electrode terminal of the battery cell. The wiring part has a first flexible substrate and a second flexible substrate, the first flexible substrate and the second flexible substrate are flexible and integrally connected to each other. A connection portion where the first flexible substrate and the second flexible substrate are connected is bent. The first flexible substrate is connected to the electrode terminal. The second flexible substrate is connected to the monitoring part. One of the first flexible substrate and the second flexible substrate has an arm. The other of the first flexible substrate and the second flexible substrate, except the one having the arm, has a slit. The arm is fixed to the slit so that the connection portion is reinforced.

[0015] By fixing the arm to the slit, the connection portion of the first flexible substrate and the second flexible substrate in the bent state is reinforced. Thus, even when stress concentration occurs at the connection portion due to expansion caused by heat of the first flexible substrate and the second flexible substrate, for example, the reinforcement can prevent damage at the connection portion. As a result, this can prevent the life of the wiring portion from deteriorating.

[0016] According to another aspect of the present disclosure, a monitoring device includes: a plurality of series terminals, the plurality of series terminals connecting a positive electrode terminal of a first unit with a negative electrode terminal of a second unit, the first unit and the second unit being included in at least three battery cells arranged in a first direction and placed adjacent to each other; a wiring portion, the wiring portion having a wiring pattern connected to the series terminals; and a monitoring portion, the monitoring portion monitoring the voltage of each battery cell input through the wiring pattern. Each series terminal includes: a connecting portion, the connecting portion extending in a first direction to connect to the positive electrode terminal and the negative electrode terminal; and a connecting portion extending from a midpoint between a first connection point and a second connection point, at which the positive electrode terminal is connected to the connecting portion, and at which the negative electrode terminal is connected to the connecting portion. The wiring pattern of the wiring portion is connected to the connecting portion.

[0017] The connection portion extending from the midpoint of the connecting portion is connected to the wiring pattern. Therefore, the voltage drop of the voltage detected in each of the plurality of wiring patterns due to the current and resistance of the series terminals can be equal to each other. As a result, this can prevent the voltage detection accuracy from changing. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description with reference to the accompanying drawings. In the accompanying drawings:

[0019] Figure 1 It is the circuit diagram of the battery pack;

[0020] Figure 2 It is a top view showing a battery stack.

[0021] Figure 3 is a top view showing a state where the monitoring device is placed on a battery stack;

[0022] Figure 4 is a side view showing a state where the monitoring device is placed on a battery stack;

[0023] Figure 5 is a top view showing a monitoring device according to a first embodiment;

[0024] Figure 6 is a top view showing a state where the arm is bent;

[0025] Figure 7 is a top view showing the wiring portion in a bent state;

[0026] Figure 8 is a side view for describing a modified example of the monitoring device;

[0027] Fig. 9is a side view for explaining a modified example of the monitoring device;

[0028] Fig.10 is a top view showing a modified example of the monitoring device;

[0029] Fig.11 is a top view showing a state where the monitoring device is placed on a battery stack;

[0030] Fig.12 is a side view showing a state where the monitoring device is placed on a battery stack;

[0031] Fig.13 is a top view showing a monitoring device according to a second embodiment;

[0032] Fig.14 is a top view showing a state where the arm is bent;

[0033] Fig.15 is a side view showing a state where the wiring portion is bent once;

[0034] Fig.16 is a side view showing a state where the wiring portion is bent twice;

[0035] Fig.17 It is the circuit diagram of the battery pack;

[0036] Fig.18 1 is a top view showing a battery stack;

[0037] Fig.19 is a top view of the monitoring device;

[0038] Fig. 20 is a top view showing a state where the monitoring device is placed on a battery stack;

[0039] Fig.21 is a top view showing the monitoring device in a state where an unnecessary second protrusion is removed;

[0040] Fig. 22 is a top view illustrating the series terminals;

[0041] Fig.23 is a schematic diagram describing voltage detection of a battery cell.

[0042] Fig.24 The diagram is a diagram for describing voltage detection of a battery cell when the connection points are different.

[0043] Fig.25 The diagram is a diagram for describing voltage detection of a battery cell when the connection points are different in a comparison structure.

[0044] Fig.26AIt is a schematic diagram showing a modified example of the series terminal.

[0045] Fig.26B is a schematic diagram showing a modified example of a series terminal;

[0046] Fig. 27 It is a top view showing a modified example of the monitoring device. DETAILED DESCRIPTION

[0047] Hereinafter, embodiments will be described with reference to the accompanying drawings.

[0048] (First embodiment)

[0049] Figures 1 to 7 A battery pack monitoring device according to the present embodiment is described. In the present embodiment, an example in which a battery pack is applied to a hybrid vehicle is described.

[0050] (Battery Pack Overview)

[0051] The battery pack 400 is used as a power supply for the electric load of the hybrid vehicle. The electric load has an electric generator that realizes the functions of a power supply source and a power generation source. For example, when the electric generator performs a power operation, the battery pack 400 discharges to supply power to the electric generator. When the electric generator generates power, the battery pack 400 is charged with the power generated by the power generation.

[0052] The battery pack 400 has a battery ECU 300. The battery ECU 300 is electrically connected to each ECU (also referred to as an on-vehicle ECU) mounted on the hybrid vehicle. The battery ECU 300 and the on-vehicle ECU send or receive signals to each other to perform cooperative control on the hybrid vehicle. Due to the cooperative control, the power generation and electric operation of the motor generator are controlled according to the charge amount of the battery pack 400, and the output of the internal combustion engine, etc. are controlled.

[0053] ECU is an abbreviation for electronic control unit. ECU has at least one computing processing unit (also called CPU) and at least one memory device (also called MMR) as a storage medium for storing programs and data. ECU has a microcontroller, and the microcontroller has a computer-readable storage medium. The storage medium corresponds to a non-transitory tangible storage medium that stores a readable program non-temporarily by a computer. The storage medium may have a semiconductor memory, a magnetic disk, etc.

[0054] The battery pack 400 includes a battery module 200 . Figure 2 The battery module 200 shown has a battery stack 210 in which a plurality of battery cells 220 are electrically and mechanically connected in series.

[0055] The battery pack 400 has a monitoring device 100. The monitoring device 100 detects the voltage of each battery cell 220 constituting the battery stack 210. The monitoring device 100 outputs the monitoring result to the battery ECU 300. The battery ECU 300 determines the equalization of the SOC of each of the plurality of battery cells 220 based on the monitoring result of the monitoring device 100. The battery ECU 300 outputs an instruction for equalization processing to the monitoring device 100 based on the judgment. The monitoring device 100 performs an equalization processing for equalizing the SOC of the plurality of battery cells 220 according to the instruction input from the battery ECU 300. SOC is an abbreviation for state of charge.

[0056] The battery pack 400 has the monitoring device 100, the battery module 200, and the battery ECU 300. In addition to the monitoring device 100, the battery module 200, and the battery ECU 300, the battery pack 400 has a blower fan (not shown) that cools the battery module 200. The battery ECU 300 controls actuation of the blower fan.

[0057] The battery pack 400 is placed in a layout space under a seat of a hybrid vehicle, for example. The layout space under the rear seat may be larger than the layout space under the front seat. Therefore, the battery pack 400 in the present embodiment may be placed in the layout space under the rear seat. However, the placement position of the battery pack 400 is not limited to the layout space under the rear seat. The battery pack 400 may be placed, for example, between the rear seat and the trunk space, between the driver's seat or the front passenger seat, etc. In the following, the battery module 200 and the monitoring device 100 are described.

[0058] (Overview of battery module)

[0059] The three directions orthogonal to each other may be referred to as a lateral direction, a longitudinal direction, and a height direction. In the present embodiment, the lateral direction is along the forward / reverse direction of the hybrid vehicle. The longitudinal direction is along the right / left direction of the hybrid vehicle. The height direction is along the vertical direction of the hybrid vehicle. In addition, the three directions orthogonal to each other may be referred to as a first direction, a second direction, and a third direction.

[0060] The battery module 200 has a battery stack 210. The battery module 200 has a battery case (not shown) that accommodates the battery stack 210. The battery case has an outer shell and a cover. The outer shell is made of aluminum die casting. The outer shell can also be made by stamping of iron or stainless steel. The cover is formed of a resin material or a metal material.

[0061] The housing has a box shape, which is open in the height direction and has a bottom. The opening of the housing is covered by a cover. The housing and the cover form a storage space for accommodating the battery stack 210. The storage space has a flow path for air flow. At least one of the housing and the cover has a communication hole that connects the external atmosphere with the flow path.

[0062] The battery stack 210 has a plurality of battery cells 220. These plurality of battery cells 220 are arranged in a longitudinal direction (also referred to as placed). The plurality of battery cells 220 are electrically and mechanically connected in series. Therefore, the output voltage of the battery module 200 is obtained by summing the output voltages of the plurality of battery cells 220.

[0063] (Overview of monitoring device)

[0064] like Figure 1 As shown, the monitoring device 100 has: a monitoring portion 10 that monitors the voltage of a plurality of battery cells 220 ; and a wiring portion 30 that electrically connects the monitoring portion 10 to each of the plurality of battery cells 220 .

[0065] The monitoring portion 10 is placed with the battery module 200 so that the monitoring portion 10 is aligned with the battery stack 210 in the longitudinal direction or the height direction. The wiring portion 30 is placed with the battery module 200 so that the monitoring portion 10 is aligned with the battery stack 210 in the height direction.

[0066] (Structure of battery stack)

[0067] The battery stack 210 has a plurality of battery cells 220. Figure 2 As shown, the battery cell 220 has a quadrangular prism shape. The battery cell 220 has six surfaces.

[0068] The battery cell 220 has an upper end surface 220a and a lower end surface 220b facing the height direction. The battery cell 220 has a first side surface 220c and a second side surface 220d facing the lateral direction. The battery cell 220 has a first main surface 220e and a second main surface 220f facing the length direction. Among the six surfaces, the first main surface 220e and the second main surface 220f have a larger area than the other four surfaces.

[0069] In the battery cell 220, the length in the longitudinal direction is shorter than the length in the height direction and the length in the lateral direction. Therefore, the battery cell 220 has a flat shape with a short longitudinal length. A plurality of battery cells 220 are arranged in the longitudinal direction.

[0070] The battery cell 220 corresponds to a secondary battery. Specifically, the battery cell 220 corresponds to a lithium-ion secondary battery. The lithium-ion secondary battery generates an electromotive force through a chemical reaction. The generation of the electromotive force causes current to flow in the battery cell 220. As a result, gas is generated in the battery cell 220. The battery cell 220 may expand. The battery cell 220 is not limited to a lithium-ion secondary battery. As the battery cell 220, for example, a nickel-hydrogen secondary battery, an organic-based battery, etc. can be used.

[0071] The first main surface 220e and the second main surface 220f of the battery cell 220 have a larger area than the other four surfaces. Therefore, in the battery cell 220, the first main surface 220e and the second main surface 220f can be easily expanded. Thus, the battery cell 220 can be expanded in the longitudinal direction. That is, the battery cell 220 can be expanded in the direction in which the plurality of battery cells 220 are arranged.

[0072] The battery stack 210 has a restraint (not shown). The restraint mechanically connects the plurality of battery cells 220 in series along the longitudinal direction. The restraint prevents the size of the battery stack 210 from increasing, which is caused by each expansion of the plurality of battery cells 220. A gap is provided between the battery cells 220 adjacent to each other. Air passes through the gap, and heat dissipation of each battery cell 220 is promoted. The longitudinal direction may correspond to a predetermined direction.

[0073] The positive electrode terminal 221 and the negative electrode terminal 222 are formed on the upper end surface 220a of the battery cell 220. The positive electrode terminal 221 and the negative electrode terminal 222 are arranged separately from each other in the lateral direction. The positive electrode terminal 221 is positioned toward the first side 220c. The negative electrode terminal 222 is positioned toward the second side 220d. The upper end surface 220a corresponds to the formation surface.

[0074] like Figure 2 As shown, between two battery cells 220 arranged adjacent to each other, each first main surface 220e faces each other, and each second main surface 220f faces each other. Thus, the upper end surfaces 220a of the two battery cells 220 arranged adjacent to each other are arranged in the longitudinal direction. In the two battery cells 220 arranged adjacent to each other, the positive electrode terminal 221 of one battery cell 220 and the negative electrode terminal 222 of the other battery cell 220 are arranged in the longitudinal direction. As a result, in the battery stack 210, the positive electrode terminal 221 and the negative electrode terminal 222 are arranged alternately in the longitudinal direction.

[0075] The battery stack 210 has: a first electrode terminal group 211 in which negative electrode terminals 222 and positive electrode terminals 221 are alternately arranged in the longitudinal direction; and a second electrode terminal group 212 in which positive electrode terminals 221 and negative electrode terminals 222 are alternately arranged in the longitudinal direction. The positive electrode terminals 221 and negative electrode terminals 222 in the first electrode terminal group 211 are arranged in the opposite order to the second electrode terminal group 212. The first electrode terminal group 211 and the second electrode terminal group 212 are arranged separately from each other in the transverse direction.

[0076] Among the electrode terminals constituting the first electrode terminal group 211 and the second electrode terminal group 212, one positive electrode terminal 221 and one negative electrode terminal 222 adjacent to each other in the longitudinal direction are mechanically and electrically connected by a series terminal 223 extending in the longitudinal direction. Thus, the plurality of battery cells 220 constituting the battery stack 210 are electrically connected in series.

[0077] The battery stack 210 in this embodiment has nine battery cells 220. Therefore, the total number of positive electrode terminals 221 and negative electrode terminals 222 is eighteen. Figures 1 to 4 As shown, these eighteen electrode terminals are given numerical symbols (n-number, n is 0 to 17) that increase from the lowest potential to the highest potential.

[0078] like Figure 2 As shown, the positive electrode terminal 1 of No. 1 and the negative electrode terminal 2 of No. 2 are arranged adjacent to each other in the longitudinal direction. The positive electrode terminal 221 and the negative electrode terminal 222 arranged adjacent to each other in the longitudinal direction are connected by a series terminal 223.

[0079] Similarly, in the first electrode terminal group 211, electrode terminals No. 1 and No. 2, electrode terminals No. 5 and No. 6, electrode terminals No. 9 and No. 10, and electrode terminals No. 13 and No. 14 are connected through the series terminal 223. In the second electrode terminal group 212, electrode terminals No. 3 and No. 4, electrode terminals No. 7 and No. 8, electrode terminals No. 11 and No. 12, and electrode terminals No. 15 and No. 16 are connected through the series terminal 223. Nine battery cells 220 are connected in series through a total of eight series terminals 223.

[0080] In the connection configuration, the negative electrode terminal 222 of No. 0 has the lowest potential. The negative electrode terminal 222 of No. 0 has a ground potential. The positive electrode terminal 221 of No. 17 has the highest potential. The positive electrode terminal 221 of No. 17 has a potential obtained by summing the output of each battery cell 220.

[0081] The negative electrode terminal 222 with the lowest potential and the positive electrode terminal 221 with the highest potential are connected to the output terminal 224. The two output terminals 224 are electrically connected to the electric load. As a result, the potential difference between the lowest potential and the highest potential is output as the output voltage of the battery module 200 to the electric load.

[0082] (Circuit Configuration of Monitoring Device)

[0083] refer to Figure 1 , describing the circuit structure of the monitoring device 100.

[0084] like Figure 1 As shown, the monitoring part 10 has a wiring substrate 11, a first electronic component 12 and a monitoring IC chip 13. The first electronic component 12 and the monitoring IC chip 13 are mounted on the wiring substrate 11. The first electronic component 12 and the monitoring IC chip 13 are electrically connected through a substrate connection 14 of the wiring substrate 11.

[0085] The wiring portion 30 is connected to the wiring substrate 11. The wiring portion 30 is connected to the battery stack 210. Thus, the monitoring portion 10 is electrically connected to the battery stack 210 through the wiring portion 30.

[0086] A connector (not shown) is placed on the wiring substrate 11 . Figure 1 The monitoring portion 10 and the battery ECU 300 are electrically connected via the wire 301.

[0087] The wiring portion 30 has a flexible substrate 31 and a plurality of wiring patterns 32 formed on the flexible substrate 31 .

[0088] The plurality of wiring patterns 32 are connected to the series terminal 223 and the output terminal 224. A plurality of substrate wirings 14 are formed on the wiring substrate 11 in accordance with each of the plurality of wiring patterns 32. These plurality of wiring patterns 32 and the plurality of substrate wirings 14 are electrically connected.

[0089] Hereinafter, in order to simplify the description, the wiring pattern 32 and the substrate wiring 14 which are electrically connected to each other are collectively referred to as a voltage detection line.

[0090] like Figure 1 As shown, the second electronic component 60 is mounted on the flexible substrate 31. The second electronic component 60 has a fuse 61 and an inductor 62. The monitoring portion 10 has a Zener diode 15, a parallel capacitor 16, and a resistor 17 as the first electronic component 12. Each of the Zener diode 15, the parallel capacitor 16, and the resistor 17 is mounted on the wiring substrate 11.

[0091] like Figure 1As shown, the fuse 61, the inductor 62 and the resistor 17 are placed in each of the plurality of voltage detection lines. The fuse 61, the inductor 62 and the resistor 17 are connected in series in sequence from the battery cell 220 to the monitoring IC chip 13.

[0092] Each of the Zener diode 15 and the parallel capacitor 16 is connected in parallel between two voltage detection lines arranged in order of potential. Specifically, the Zener diode 15 and the parallel capacitor 16 are connected between the inductor 62 and the resistor 17 in the voltage detection line. The anode of the Zener diode 15 is connected to the low potential side of the two adjacent voltage detection lines. The cathode of the Zener diode 15 is connected to the high potential side of the two adjacent voltage detection lines.

[0093] In the connection structure, the resistor 17 and the parallel capacitor 16 form an RC circuit. The RC circuit and the inductor 6 are used as a filter to reduce noise during voltage detection.

[0094] The Zener diode 15 has a structure in which a short circuit failure occurs when an overvoltage is applied from the battery module 200. Specifically, the Zener diode 15 has a structure in which a PN junction type IC chip is directly clamped by a pair of leads. Thus, for example, unlike a configuration in which an IC chip and leads are indirectly connected by wires, the Zener diode 15 can avoid an open circuit failure caused by a wire breakage due to an overvoltage.

[0095] Since a large current flows in the voltage detection line when an overvoltage causes a short-circuit failure of the Zener diode 15, the fuse 61 is disconnected. The rated current of the fuse 61 is set to a standard of a large current flowing in the voltage detection line when an overvoltage causes a short-circuit failure of the Zener diode 15. The disconnection of the fuse 61 prevents a large current from flowing into the monitoring IC chip 13.

[0096] like Figure 1 As shown, the monitoring IC chip 13 has: a driver 18 that performs signal processing such as amplification; and a switch 19 according to each of the plurality of battery cells 220. The switch 19 controls the electrical connection between the two voltage detection lines arranged in order of potential. One end of the switch 19 is connected to the wiring of the monitoring IC chip 13 connected to one of the two voltage detection lines arranged in order of potential. The other end of the switch 19 is connected to the wiring of the monitoring IC chip 13 connected to the other of the two voltage detection lines arranged in order of potential. The switching control of the switch 19 controls the charging / discharging of the battery cell 220 electrically connected to the two voltage detection lines connected to the switch 19.

[0097] like Figure 1As shown, the monitoring IC chip 13 is electrically connected to each of the plurality of voltage detection lines. Therefore, the monitoring IC chip 13 receives the output voltage of each of the plurality of battery cells 220. The monitoring IC chip 13 outputs the output voltage (electromotive force) of each of the plurality of battery cells 220 to the battery ECU 300.

[0098] There is a correlation between the state of charge (SOC) and the electromotive force of the battery cell 220. The battery ECU 300 stores the correlation. The battery ECU 300 detects the SOC of each of the plurality of battery cells 220 based on the stored correlation and the output voltage (electromotive force) input from the monitoring IC chip 13.

[0099] The battery ECU 300 determines the equalization process of the SOC of the plurality of battery cells 220 based on the detection result. The battery ECU 300 outputs an instruction of the equalization process to the driver 18 of the monitoring IC chip 13 based on the determination. The driver 18 follows the instruction of the equalization process to perform switching control of the switch 19 according to each of the plurality of battery cells 220. Thus, the plurality of battery cells 220 are charged and discharged. The SOC of the plurality of battery cells 220 is equalized.

[0100] The battery ECU 300 detects the charging state of the battery stack 210 based on the input voltage, etc. The battery ECU 300 outputs the detected charging state of the battery stack 210 to the vehicle-mounted ECU. The vehicle-mounted ECU outputs a command signal to the battery ECU 300 based on the charging state and vehicle information input from various sensors installed on the vehicle, ignition switch, etc., such as the depression amount of the accelerator pedal and the throttle opening. The battery ECU 300 controls the connection between the battery stack 210 and the electric load based on the command signal.

[0101] A system main relay (not shown) is placed between the battery stack 210 and the electric load. The system main relay controls the electrical connection between the battery stack 210 and the electric load by generating a magnetic field. The battery ECU 300 controls the connection between the battery stack 210 and the electric load by controlling the generation of the magnetic field of the system main relay.

[0102] (Structure of the monitoring part)

[0103] refer to Figure 3 and Figure 4 The configuration of the monitoring section 10 is described below. In order to avoid complication of the description, Figure 3 , reference numerals of the constituent elements of the battery stack 210 are omitted. Figure 4 The cross-sectional shape of the monitoring device 100 is shown in order to clearly show the slit 36 ​​and the arm 37. This omission will similarly apply to the other side views.

[0104] The monitoring part 10 has a wiring substrate 11, a first electronic component 12, and a monitoring IC chip 13. The monitoring IC chip 13 is mounted on the front surface 11a of the wiring substrate 11. The first electronic component 12 is mounted on at least one of the front surface 11a and the rear surface 11b of the wiring substrate 11, the rear surface 11b being the rear side of the front surface 11a.

[0105] In addition to these structural elements, the monitoring part 10 has a resin part 20. The resin part 20 covers and protects the wiring substrate 11 and the first electronic component 12 and the monitoring IC chip 13 mounted on the wiring substrate 11. The resin part 20 covers and protects the connection part of the wiring substrate 11 with the wiring part 30.

[0106] like Figure 3 and Figure 4 As shown in FIG. 1 , the resin portion 20 has a rectangular parallelepiped shape. The resin portion 20 has a mounting surface 20a facing the longitudinal direction. Figure 4 As shown, the monitoring portion 10 in this embodiment is placed on the first main surface 220e of the battery cell 220 located at one end of nine battery cells 220 arranged in the longitudinal direction. The mounting surface 20a of the resin portion 20 faces the first main surface 220e in the longitudinal direction.

[0107] The resin portion 20 may be omitted. When the monitoring portion 10 does not have the resin portion 20, the rear surface 11b of the wiring substrate 11 faces the first main surface 220e in the longitudinal direction. The wiring substrate 11 is fixed on the first main surface 220e. The first main surface 220e corresponds to the side surface.

[0108] (Structure of the wiring part)

[0109] refer to Figures 3 to 7 , describing the construction of the wiring portion 30. The wiring portion 30 has a flexible substrate 31 and a wiring pattern 32. The flexible substrate 31 is thinner than the wiring substrate 11 and is made of a flexible resin material. Therefore, the flexible substrate 31 can be bent. That is, the flexible substrate 31 is elastically deformable.

[0110] A portion of the flexible substrate 31 may have a notch or a bellows structure to be greatly deformed in the longitudinal and lateral directions (not shown). The flexible substrate 31 may have a notch or a hole to avoid obstructing wind flow in the accommodation space formed by the battery case.

[0111] The wiring pattern 32 is formed on the front surface 31a of the flexible substrate 31. The coating resin covers the wiring pattern 32. The tip of one end toward the wiring pattern 32 is exposed to the outside of each of the flexible substrate 31 and the coating resin. The tip of one end toward the wiring pattern 32 is mechanically and electrically connected to the series terminal 223 and the output terminal 224 by welding or the like. The tip of the other end toward the wiring pattern 32 is mechanically and electrically connected to the substrate wiring 14 of the wiring substrate 11 by solder or the like.

[0112] The series terminal 223 and the output terminal 224 are connected to at least one of the positive electrode terminal 221 and the negative electrode terminal 222 placed on the upper end surface 220a of the battery cell 220. The monitoring portion 10 is placed on the first main surface 220e of the battery cell 220.

[0113] The wiring portion 30 connects the series terminal 223 and the output terminal 224 placed on the upper end surface 220a with the monitoring portion 10 placed on the first main surface 220e. Therefore, a part of the wiring portion 30 is placed toward the upper end surface 220a. Another part of the wiring portion 30 is placed toward the monitoring portion 10. The wiring portion 30 is bent (also referred to as uneven) at the boundary between the part placed toward the upper end surface 220a and the part placed toward the monitoring portion 10.

[0114] Hereinafter, for the sake of simplicity of description, when the bent portion of the wiring portion 30 is set as a boundary, the portion positioned toward the upper end surface 220a may be referred to as the first wiring portion 33, and the portion positioned toward the monitoring portion 10 may be referred to as the second wiring portion 34. The first wiring portion 33 corresponds to the flexible substrate. The second wiring portion 34 corresponds to the second flexible substrate.

[0115] The boundary of the curved portion in the wiring portion 30 cannot be ideally shown by a straight line. In principle, there is a curved portion that is continuously curved at least between the first wiring portion 33 and the second wiring portion 34. However, in order to simplify the description in the embodiment, the boundary between the first wiring portion 33 and the second wiring portion 34 is simply shown by a dot-dash line, as shown in FIG. Figure 6 shown.

[0116] (First wiring part)

[0117] The first wiring portion 33 has a shape extending in the longitudinal direction. A portion of the first wiring portion 33 is placed between the first electrode terminal group 211 and the second electrode terminal group 212 on the upper end surface 220a of the plurality of battery cells 220. Another portion of the first wiring portion 33 protrudes from the upper end surface 220a and faces the monitoring portion 10 separately in the height direction.

[0118] A plurality of protrusions 35 extending toward the electrode terminal groups are formed between the first electrode terminal group 211 and the second electrode terminal group 212 in the flexible substrate 31 of the first wiring portion 33. These plurality of protrusions 35 are arranged apart from each other in the longitudinal direction.

[0119] One end of the wiring pattern 32 is placed on the plurality of protrusions 35. The tip toward one end of the wiring pattern 32 is exposed to the outside of the flexible substrate 31 coated with resin and constituting the protrusions 35. The tip toward one end of the wiring pattern 32 is connected to the series terminal 223 or the output terminal 224.

[0120] A slit 36 ​​penetrating the front surface 31a of the flexible substrate 31 and the rear surface 31b as the rear side is formed in a portion of the flexible substrate 31 of the first wiring portion 33, the portion facing apart from the monitoring portion 10. The arm 37 is inserted into the slit 36 ​​to be fixed.

[0121] In the present embodiment, two slits 36 are formed in the first wiring portion 33. The two slits 36 are arranged apart from each other in the transverse direction. The opening of the slit 36 ​​has a rectangular shape. The length of the opening in the longitudinal direction is longer than the length in the transverse direction. A configuration in which the transverse length is longer than the longitudinal length can be used for the opening of the slit 36. The number of the slits 36 is not limited to two.

[0122] (Second wiring part)

[0123] The second wiring portion 34 has a shape extending in the height direction. A portion of the second wiring portion 34 is placed in the monitoring portion 10. Another portion of the second wiring portion 34 is arranged apart from the first main surface 220e placed on the monitoring portion 10 in the longitudinal direction.

[0124] The length of the second wiring portion 34 in the extending direction is shorter than the length of the first wiring portion 33 in the extending direction. That is, the length of the second wiring portion 34 in the height direction is shorter than the length of the first wiring portion 33 in the longitudinal direction. In other words, the length of the first wiring portion 33 in the longitudinal direction is longer than the length of the second wiring portion 34 in the height direction.

[0125] The other end of the wiring pattern 32 is placed on a portion of the second wiring portion 34 in the flexible substrate 31, which is placed in the monitoring portion 10. The tip toward the other end of the wiring pattern 32 is exposed to the coating resin and the outside of the flexible substrate 31. The tip toward the other end of the wiring pattern 32 is connected to the substrate wiring 14 formed on the front surface 11a of the wiring substrate 11. The flexible substrate 31 is connected to the front surface 11a of the wiring substrate 11. The tip toward the other end of the wiring pattern 32 and the flexible substrate 31 can be connected to the rear surface 11b of the wiring substrate 11.

[0126] It is also possible to adopt a configuration in which the tip of the other end toward the wiring pattern 32 is not exposed to the outside of the coating resin and the flexible substrate 31. In this case, a through hole for electrically connecting the other end of the wiring pattern 32 with the substrate wiring 14 is formed in a portion of the second wiring portion 34 on the flexible substrate 31, which portion is placed in the monitoring portion 10. The through hole is used to electrically connect the front surface 31a with the rear surface 31b of the flexible substrate 31. Due to the connection between the through hole and the substrate wiring 14, the wiring pattern 32 is electrically connected to the substrate wiring 14 through the through hole.

[0127] The arm 37 inserted into the slit 36 ​​to be fixed is formed in a portion facing apart from the first main surface 220e in the longitudinal direction, and a portion of the second wiring portion 34 on the flexible substrate 31 is placed in the monitoring portion 10. Figure 5 As shown, the length of the second wiring portion 34 in the transverse direction is shorter than that of the first wiring portion 33. The second wiring portion 34 is aligned with two slits 36 in the longitudinal direction on both sides in the longitudinal direction. Arms 37 extend from the both sides of the second wiring portion 34. The number of arms 37 is not limited to two.

[0128] The arm 37 has a supporting portion 38 and an inserting portion 39. The supporting portion 38 integrally extends from one side of the second wiring portion 34. The inserting portion 39 is integrally coupled to the supporting portion 38.

[0129] like Figure 4 As shown, the support portion 38 has a right triangle shape. One of the two side surfaces forming the right angle of the support portion 38 is integrally connected to the flexible substrate 31 of the second wiring portion 34. The other of the two sides forming the right angle of the support portion 38 is integrally connected to the rear surface 31b of the flexible substrate 31 of the first wiring portion 33.

[0130] The insertion portion 39 extends in the height direction from the first wiring portion 33 side of the support portion 38, and the side surface of the first wiring portion 33 contacts the rear surface 31b of the flexible substrate 31. A part of the insertion portion 39 is inserted into the slit 36. The part of the insertion portion 39 inserted into the slit 36 ​​is fixed to the first wiring portion 33 by an adhesive, solder, welding, etc. Not only the insertion portion 39 but also the support portion 38 may be fixed to the first wiring portion 33.

[0131] As described above, both sides of the right angle of the support portion 38 forming the arm 37 are connected to the second wiring portion 34 and the first wiring portion 33. The arm 37 and the slit 36 ​​serve as a rib to reinforce the connection between the first wiring portion 33 and the second wiring portion 34.

[0132] (Assembly)

[0133] The process flow of assembling the monitoring device 100 to the battery stack 210 is described. Figure 5 The monitoring device 100 is shown before being assembled with the battery stack 210 . At this time, the wiring portion 30 is not bent. The wiring portion 30 has a shape extending in the longitudinal direction. The arm 37 extends laterally away from the flexible substrate 31 .

[0134] Each of the two arms 37 has a fold line Figure 5 The dot-dash line shown is bent toward the rear surface 31b of the flexible substrate 31. Thus, the two arms 37 extend away from the rear surface 31b in the height direction. The lateral position of the insertion portion 39 of the arm 37 coincides with the lateral position of the slit 36.

[0135] The second wiring portion 34 extends along the folding line. Figure 6 The dot-dash line shown in FIG. 1 is bent toward the rear surface 31b of the flexible substrate 31 of the first wiring portion 33. As a result, Figure 4 and Figure 7 As shown, the second wiring portion 34 extends in the height direction. Figure 4 As shown, the wiring portion 30 (monitoring device 100) has a shape bent into an L shape. The wiring portion 30 is bent according to the outer shape of the battery stack 210. The wiring portion 30 is not bent in a direction away from the battery stack 210, but is bent in a direction close to the battery stack 210.

[0136] At this time, the insertion portion 39 of the arm 37 is inserted into the slit 36. Then, the insertion portion 39 is mechanically connected to the first wiring portion 33. Thus, the bent state of the first wiring portion 33 and the second wiring portion 34 is maintained. The L-shaped bent state of the monitoring device 100 is maintained.

[0137] like Figure 3 As shown, the first wiring portion 33 is placed on the upper end surface 220a of the plurality of battery cells 220. Figure 4 As shown, the mounting surface 20a of the resin 20 is placed on the first main surface 220e. One end of the wiring pattern 32 is connected to the series terminal 223 and the output terminal 224.

[0138] The monitoring device 100 is assembled to the battery stack 210. The wiring portion 30 may be bent after one end of the wiring pattern 32 is connected to the series terminal 223 and the output terminal 224.

[0139] The operation effect of the monitoring device 100 is described. As described above, the wiring portion 30 is bent. At the bent portion, the wiring portion 30 is divided into the first wiring portion 33 and the second wiring portion 34. The first wiring portion 33 extends in the longitudinal direction. The second wiring portion 34 extends in the height direction.

[0140] The plurality of battery cells 220 are arranged in the longitudinal direction. The first main surface 220e and the second main surface 220f of the battery cell 220 facing the longitudinal direction can be easily expanded. Therefore, the plurality of battery cells 220 can be easily expanded in the longitudinal direction.

[0141] The first wiring portion 33 is placed on the upper end surface 220a of the plurality of battery cells 220. The first wiring portion 33 is coupled to each of the series terminal 223 and the output terminal 224 coupled to the plurality of battery cells 220. The length of the first wiring portion 33 in the longitudinal direction is longer than the length of the second wiring portion 34 in the height direction.

[0142] Due to the above configuration, the first wiring portion 33 can easily expand and contract in the longitudinal direction. Due to the expansion and contraction, stress concentration easily occurs at the connection portion where the first wiring portion 33 and the second wiring portion 34 are connected in a bent state.

[0143] In contrast, in the monitoring device 100, the slit 36 ​​is formed in the first wiring portion 33. The arm 37 is formed in the second wiring portion 34. The arm 37 is mechanically connected to the slit 36. Thus, the strength of the connecting portion where the first wiring portion 33 and the second wiring portion 34 are connected in a bent state is enhanced. Therefore, for example, even when stress concentration occurs at the connecting portion due to the above-mentioned expansion and contraction, damage at the connecting portion can be prevented. Contact failure is prevented from occurring at the wiring pattern 32 passing through the connecting portion. As a result, this can prevent the life of the wiring portion 30 from being deteriorated.

[0144] As described above, reinforcement of the bent portion of the wiring portion 30 is performed by using the arm 37 and the slit 36. That is, reinforcement of the bent portion of the wiring portion 30 is performed by using a part of the constituent material of the wiring portion 30. Therefore, compared with a structure in which reinforcement of the bent portion of the wiring portion 30 is performed by a material completely different from the wiring portion 30, an increase in the number of components can be prevented.

[0145] The slit 36 ​​is formed in the first wiring portion 33 , which can be easily expanded and contracted in the longitudinal direction. Therefore, the fixing portion between the arm 37 and the slit 36 ​​is placed in the first wiring portion 33 .

[0146] Thus, the expansion and contraction of the first wiring portion 33 is divided into two parts by the fixed portion between the arm 37 and the slit 36. The expansion and contraction of the first wiring portion 33 reduces the stress applied to the connecting portion. Thus, the life of the wiring portion 30 can be effectively prevented from being deteriorated.

[0147] (First Modification)

[0148] In this embodiment, if Figure 4 As shown, the length between the mounting surface 20a of the resin portion 20 and the rear surface 11b of the wiring substrate 11 is longer than the length between the front surface 11a of the wiring substrate 11 and the rear surface 11b of the wiring substrate. Figure 8 As shown, a configuration may be adopted in which the length between the mounting surface 20a of the resin portion 20 and the rear surface 11b is shorter than the length between the front surface 11a and the rear surface 11b of the wiring substrate 11. In this case, for both sides forming a right angle of the support portion 38, the length of the side in contact with the rear surface 31b of the flexible substrate 31 of the first wiring portion 33 is shorter than the length of the side integrally connected with the flexible substrate 31 of the second wiring portion 34. An increase in the size of the monitoring device 100 in the longitudinal direction is prevented.

[0149] (Second Modification)

[0150] In the present embodiment, it is exemplified that the slit 36 ​​is formed in the first wiring portion 33 and the arm 37 is formed in the second wiring portion 34. Fig. 9 As shown, a configuration may be adopted in which the arm 37 is formed in the first wiring portion 33 , and the slit 36 ​​is formed in the second wiring portion 34 .

[0151] (Third Modification)

[0152] In the present embodiment, the wiring portion 30 is exemplified as having one flexible substrate 31. Fig.10 As shown, a configuration in which the wiring portion 30 has two flexible substrates 31 may be adopted. In this modification, the two flexible substrates 31 are arranged apart from each other in the lateral direction. The wiring pattern 32 according to the first electrode terminal group 211 is formed on one of the two flexible substrates 31. The wiring pattern 32 according to the second electrode terminal group 212 is formed on the other of the flexible substrates 31.

[0153] (Fourth Modification)

[0154] like Fig.10 As shown, a configuration may be adopted in which a reinforcing material 40 having higher rigidity than the forming material of the flexible substrate 31 is placed in the arm 37. For example, copper or the like may be used for the reinforcing material 40. The same material as the wiring pattern 32 may be used for the reinforcing material 40.

[0155] The reinforcing material 40 described above increases the strength of the arm 37. Thus, the strength of the joint where the first wiring portion 33 and the second wiring portion 34 are joined can be more effectively improved. The reinforcing material 40 may be placed on at least the support portion 38. The reinforcing material 40 may not be inserted into the insertion portion 39.

[0156] (Second embodiment)

[0157] refer to Figures 11 to 16 , a second embodiment is described. The monitoring device according to each embodiment described below has many similarities with the embodiment described above. Therefore, in the following, the description of similar parts is omitted. The different parts are mainly described. In the following, the same reference numerals are applied to the same elements as those described above.

[0158] In the first embodiment, the monitoring portion 10 is exemplified as being placed on the first main surface 220e. Fig.11 and Fig.12 As shown, the monitoring portion 10 is placed on the upper end surface 220a.

[0159] In order to adopt the corresponding structure, not only the boundary between the first wiring portion 33 and the second wiring portion 34, but also the second wiring portion 34 is bent as described below. The support portion 38 of the arm 37 in this embodiment has a rectangular shape extending away from the second wiring portion 34. The insertion portion 39 has a rectangular shape having a length in an orthogonal direction orthogonal to the extending direction of the support portion 38, which is longer than the length of the support portion 38 in the orthogonal direction.

[0160] Fig.13 The monitoring device 100 is shown before it is assembled with the battery stack 210. In this state, the support portion 38 extends in the lateral direction. The insertion portion 39 extends in the longitudinal direction at the tip of the support portion 38.

[0161] like Fig.13 As shown by the arrows in , each of the two arms 37 is bent to face the front surface 31a of the flexible substrate 31. Each of the two arms 37 is bent to be separated from the front surface 31a. Therefore, the insertion portion 39 toward the tip of the support portion 38 in the arm 37 extends away from the front surface 31a in the height direction. The lateral position of the insertion portion 39 coincides with the lateral position of the slit 36.

[0162] The second wiring portion 34 is formed along the bending line. Fig.14 The dot-dash line shown in FIG. 3 is bent toward the front surface 31a of the flexible substrate 31 of the first wiring portion 33. Fig.15 As shown, the second wiring portion 34 and the monitoring portion 10 face the first wiring portion 33 in the height direction.

[0163] At this time, the insertion portion 39 is inserted into the slit 36. The insertion portion 39 is mechanically connected to the first wiring portion 33. Thus, the bent state of the first wiring portion 33 and the second wiring portion 34 is maintained.

[0164] The second wiring portion 34 is bent so that the monitoring portion 10 is bent along the bending line. Fig.14 The long double-dotted line shown in FIG. 1 is directed toward the rear surface 31b of the flexible substrate 31 of the second wiring portion 34. Fig.16 As shown, the monitoring portion 10 faces the second wiring portion 34 in the height direction. Fig.12 As shown, the first wiring portion 33 , the second wiring portion 34 , and the monitoring portion 10 overlap on the upper end surfaces 220 a of the plurality of battery cells 220 .

[0165] The monitoring device 100 in this embodiment has similar constituent elements to the monitoring device 100 described in the first embodiment. Therefore, similar effects can be provided.

[0166] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments and may be implemented in various modified examples without departing from the scope of the present disclosure.

[0167] (Fifth Modification)

[0168] In the present embodiment, it is exemplified that the fuse 61 and the inductor 62 are placed on the flexible substrate 31. Instead, for example, a configuration in which the Zener diode 15, the parallel capacitor 16, and the resistor 17 are placed on the flexible substrate 31 in addition to the fuse 61 and the inductor 62 may also be adopted.

[0169] (Sixth Modification)

[0170] In the present embodiment, it is exemplified that the wiring pattern 32 is placed on the front surface 31a. However, a configuration in which the wiring pattern 32 is placed on the rear surface 31b may be adopted.

[0171] (Seventh Modification)

[0172] In each embodiment, the battery stack 210 is illustrated to have nine battery cells 220 . However, the number of battery cells 220 of the battery stack 210 is not limited to the example described above, and may also be a plural number. The battery stack 210 may have an even number of battery cells 220 .

[0173] In each embodiment, it is illustrated that the battery module 200 has one battery stack 210. However, the battery module 200 may have a plurality of battery stacks 210. In this case, the housing of the battery module 200 has a housing space according to each battery stack 210. These plurality of housing spaces are arranged in the lateral direction.

[0174] For example, when the battery cells 220 of two battery stacks 210 are connected in series, each of the two battery stacks 210 has the same even number of battery cells 220. The multiple battery cells 220 of each of the two battery stacks 210 are arranged in the longitudinal direction. The wire electrically connects the negative electrode terminal 222 of the battery cell 220 located at the right end in the longitudinal direction of one of the two battery stacks 210 with the positive electrode terminal 221 of the battery cell 220 located at the right end of the other of the two battery stacks 210. Thus, the negative electrode terminal 222 of the battery cell 220 located at the left end in the longitudinal direction of one of the two battery stacks 210 has the lowest potential. The positive electrode terminal 221 of the battery cell 220 located at the left end of the other of the two battery stacks 210 has the highest potential. The positive electrode terminal 221 with the highest potential and the negative electrode terminal 222 with the lowest potential are arranged to be arranged in the transverse direction. The wiring portion 30 is placed on each of the two battery stacks 210.

[0175] (Other Modifications)

[0176] In the present embodiment, the battery pack 400 is applied to a hybrid vehicle, but the battery pack 400 may be applied to, for example, a plug-in hybrid vehicle and an electric vehicle.

[0177] Furthermore, the inventors found the following.

[0178] (Third Embodiment)

[0179] Figures 18 to 27 denoted by . In this embodiment, an example in which a battery pack is applied to a hybrid vehicle is described.

[0180] (Battery Pack Overview)

[0181] The battery pack 1400 is used as a power supply for the electric load of the hybrid vehicle. The electric load has an electric generator that serves as a power supply source and a power supply source. For example, when the electric generator performs a power operation, the battery pack 1400 is discharged to supply power to the electric generator. When the electric generator generates power, the battery pack 1400 is charged with the power generated by the power generation.

[0182] The battery pack 1400 has a battery ECU 1300. The battery ECU 1300 is electrically connected to each ECU (on-board ECU) mounted on the hybrid vehicle. The battery ECU 1300 and the on-board ECU send or receive signals to each other to perform cooperative control on the hybrid vehicle. Due to the cooperative control, the power generation and power operation of the motor generator are controlled according to the charge amount of the battery pack 1400, and the output of the internal combustion engine, etc. are controlled.

[0183] ECU is an abbreviation for electronic control unit. ECU has at least one computing processing unit (also called CPU) and at least one memory device (also called MMR) as a storage medium for storing programs and data. ECU has a microcontroller, and the microcontroller has a computer-readable storage medium. The storage medium is a non-transitory tangible storage medium that stores computer-readable programs non-temporarily. The storage medium may have a semiconductor memory, a magnetic disk, etc.

[0184] The battery pack 1400 includes a battery module 1200 . Fig.18 The battery module 1200 shown has a battery stack 1210 in which a plurality of battery cells 1220 are electrically and mechanically connected in series.

[0185] The battery pack 1400 has a monitoring device 1100. The monitoring device 1100 detects the voltage of each battery cell 1220 constituting the battery stack 1210. The monitoring device 1100 outputs the monitoring result to the battery ECU 1300. The battery ECU 1300 determines the balance of the SOC of each of the plurality of battery cells 1220 based on the monitoring result of the monitoring device 1100. The battery ECU 1300 outputs an instruction for a balance process to the monitoring device 1100 based on the judgment. The monitoring device 1100 performs a balance process for equalizing the SOC of the plurality of battery cells 1220 according to the instruction input from the battery ECU 1300. SOC is an abbreviation for state of charge.

[0186] The battery pack 1400 has the monitoring device 1100, the battery module 1200, and the battery ECU 1300. In addition to the monitoring device 1100, the battery module 1200, and the battery ECU 1300, the battery pack 1400 has a blower fan (not shown) that cools the battery module 1200. The battery ECU 1300 controls actuation of the blower fan.

[0187] The battery pack 1400 is placed in a layout space under a seat of a hybrid vehicle, for example. The layout space under the rear seat may be larger than the layout space under the front seat. Therefore, the battery pack 1400 in this embodiment may be placed in the layout space under the rear seat. However, the placement position of the battery pack 1400 is not limited to the layout space under the rear seat. The battery pack 1400 may be placed, for example, between the rear seat and the trunk, between the driver's seat or the front passenger seat, etc.

[0188] The battery module 1200 and the monitoring device 1100 are described. The three directions orthogonal to each other may be referred to as a lateral direction, a longitudinal direction, and a height direction. In the present embodiment, the lateral direction is along the forward / reverse direction of the hybrid vehicle. The longitudinal direction is along the right / left direction of the hybrid vehicle. The height direction is along the vertical direction of the hybrid vehicle. In addition, the three directions orthogonal to each other may be referred to as a first direction, a second direction, and a third direction.

[0189] (Overview of battery module)

[0190] The battery module 1200 has a battery stack 1210. The battery module 1200 has a battery case (not shown) for accommodating the battery stack 1210. The battery case has a shell and a cover. The shell is made of aluminum die casting. The shell can also be made by stamping of iron or stainless steel. The cover is formed of a resin material or a metal material.

[0191] The housing has a box shape, which is open in the height direction and has a bottom. The opening of the housing is covered by a cover. The housing and the cover form a storage space for accommodating the battery stack 1210 and the monitoring device 1100. The storage space has a flow path for air flow. At least one of the housing and the cover has a communication hole for communicating the external atmosphere with the flow channel.

[0192] The battery stack 1210 has a plurality of battery cells 1220. These plurality of battery cells 1220 are arranged in a longitudinal direction. The plurality of battery cells 1220 are electrically and mechanically connected in series. Therefore, the output voltage of the battery module 1200 is obtained by summing the output voltages of the plurality of battery cells 1220. The number of battery cells 1220 held by the battery stack 1210 is three or more. The longitudinal direction corresponds to the first direction.

[0193] (Overview of monitoring device)

[0194] like Fig.17 As shown, the monitoring device 1100 has: a monitoring portion 1010 that monitors the voltage of each of the plurality of battery cells 1220 ; and a wiring portion 1030 that electrically connects the monitoring portion 1010 to each of the plurality of battery cells 1220 .

[0195] The monitoring portion 1010 is placed with the battery module 1200 so that the monitoring portion 1010 is aligned in parallel with the battery stack 1210 in the longitudinal direction or the height direction. The wiring portion 1030 is placed with the battery module 1200 so that the monitoring portion 1010 is aligned with the battery stack 1210 in the height direction.

[0196] (Structure of battery stack)

[0197] The battery stack 1210 has a plurality of battery cells 1220. Fig.18 As shown, the battery cell 1220 has a quadrangular prism shape. The battery cell 1220 has six surfaces.

[0198] The battery cell 1220 has an upper end surface 1220a facing the height direction. The battery cell 1220 has a lower end surface (not shown) that faces the height direction and is arranged separately from the upper end surface 1220a in the height direction. The battery cell 1220 has a first side surface 1220c and a second side surface 1220d facing the lateral direction. The battery cell 1220 has a first main surface 1220e and a second main surface 1220f facing the longitudinal direction. Among the six surfaces, the first main surface 1220e and the second main surface 1220f have a larger area than the other four surfaces.

[0199] In the battery cell 1220, the length in the longitudinal direction is shorter than the length in the height direction and the length in the lateral direction. Therefore, the battery cell 1220 has a flat plate shape with a short longitudinal length. A plurality of battery cells 1220 are arranged in the longitudinal direction.

[0200] The battery cell 1220 corresponds to a secondary battery. Specifically, the battery cell 1220 corresponds to a lithium-ion secondary battery. The lithium-ion secondary battery generates an electromotive force through a chemical reaction. The generation of the electromotive force causes current to flow in the battery cell 1220. As a result, gas is generated in the battery cell 1220. The battery cell 1220 may expand. The battery cell 1220 is not limited to a lithium-ion secondary battery. As the battery cell 1220, for example, a nickel-hydrogen secondary battery, an organic-based battery, etc. can be used.

[0201] The first main surface 1220e and the second main surface 1220f of the battery cell 1220 have a larger area than the other four surfaces. Therefore, in the battery cell 1220, the first main surface 1220e and the second main surface 1220f can be easily expanded. Thus, the battery cell 1220 can be expanded in the longitudinal direction. That is, the battery cell 1220 can be expanded in the direction in which the plurality of battery cells 1220 are arranged.

[0202] The battery stack 1210 has a restraint (not shown). The restraint mechanically connects the plurality of battery cells 1220 in series along the longitudinal direction. The restraint prevents the battery stack 1210 from increasing in size due to each expansion of the plurality of battery cells 1220.

[0203] An insulating spacer is placed between the battery cells 1220 adjacent to each other. Thus, a gap is provided between the battery cells 1220 adjacent to each other. Air passes through the gap, and heat dissipation of each battery cell 1220 is promoted.

[0204] The positive electrode terminal 1221 and the negative electrode terminal 1222 are formed on the upper end surface 1220a of the battery cell 1220. The positive electrode terminal 1221 and the negative electrode terminal 1222 are arranged apart from each other in the lateral direction. The positive electrode terminal 1221 is positioned toward the first side 1220c. The negative electrode terminal 1222 is positioned toward the second side 1220d.

[0205] like Fig.18 As shown, between two battery cells 1220 arranged adjacent to each other, each first main surface 1220e faces each other, and each second main surface 1220f faces each other. The upper end surfaces 1220a of the two battery cells 1220 arranged adjacent to each other are arranged in the longitudinal direction. Thus, in the two battery cells 1220 arranged adjacent to each other, the positive electrode terminal 1221 of one battery cell 1220 and the negative electrode terminal 1222 of the other battery cell 1220 are arranged in the longitudinal direction. As a result, in the battery stack 1210, the positive electrode terminal 1221 and the negative electrode terminal 1222 are arranged alternately in the longitudinal direction.

[0206] The battery stack 1210 has: a first electrode terminal group 1211 in which negative electrode terminals 1222 and positive electrode terminals 1221 are alternately arranged in the longitudinal direction; and a second electrode terminal group 1212 in which positive electrode terminals 1221 and negative electrode terminals 1222 are alternately arranged in the longitudinal direction. The positive electrode terminals 1221 and negative electrode terminals 1222 in the first electrode terminal group 1211 are arranged in the opposite order to the second electrode terminals 1212. The first electrode terminal group 1211 and the second electrode terminal group 1212 are arranged separately from each other in the transverse direction.

[0207] Among the electrode terminals constituting the first electrode terminal group 1211 and the second electrode terminal group 1212, one positive electrode terminal 1221 and one negative electrode terminal 1222 are adjacent to each other in the vertical direction and are mechanically and electrically connected by a series terminal 1223. Thus, a plurality of battery cells 1220 constituting the battery stack 1210 are electrically connected in series. The series terminal 1223 is described below.

[0208] The battery stack 1210 in this embodiment has nine battery cells 1220. These nine battery cells 1220 are connected in series. Therefore, the total number of positive electrode terminals 1221 and negative electrode terminals 1222 is eighteen. Fig.17 and Fig.18 As shown, these eighteen electrode terminals are given numerical symbols (n number) that increase from the lowest potential to the highest potential.

[0209] like Fig.18As shown, the positive electrode terminal 1 of No. 1 and the negative electrode terminal 2 of No. 2 are arranged adjacent to each other in the longitudinal direction. The positive electrode terminal 1221 and the negative electrode terminal 1222 arranged adjacent to each other in the transverse direction are connected by a series terminal 1223.

[0210] Similarly, in the first electrode terminal group 1211, electrode terminals No. 1 and No. 2, electrode terminals No. 5 and No. 6, electrode terminals No. 9 and No. 10, and electrode terminals No. 13 and No. 14 are connected through the series terminal 1223. In the second electrode terminal group 1212, electrode terminals No. 3 and No. 4, electrode terminals No. 7 and No. 8, electrode terminals No. 11 and No. 12, and electrode terminals No. 15 and No. 16 are connected through the series terminal 1223. Nine battery cells 1220 are connected in series through a total of eight series terminals 1223.

[0211] In the connection configuration, the negative electrode terminal 1222 of No. 0 has the lowest potential. The negative electrode terminal 1222 of No. 0 has a ground potential. The positive electrode terminal 1221 of No. 17 has the highest potential. The positive electrode terminal 1221 of No. 17 has a potential obtained by summing the output of each battery cell 1220.

[0212] The negative electrode terminal 1222 with the lowest potential and the positive electrode terminal 1221 with the highest potential are connected to the output terminal 1224. The two output terminals 1224 are electrically connected to the electrical load. As a result, the potential difference between the lowest potential and the highest potential is output to the electrical load as the output voltage of the battery module 1200.

[0213] (Circuit Configuration of Monitoring Device)

[0214] refer to Fig.17 and Fig. 20 , describing the circuit structure of the monitoring device 1100.

[0215] like Fig.17 As shown, the monitoring part 1010 has a wiring substrate 1011, a first electronic component 1012 and a monitoring IC chip 1013. The first electronic component 1012 and the monitoring IC chip 1013 are mounted on the wiring substrate 1011. The first electronic component 1012 and the monitoring IC chip 1013 are electrically connected through a substrate connection 1014 of the wiring substrate 1011.

[0216] The wiring portion 1030 is connected to the wiring substrate 1011. The wiring portion 1030 is connected to the battery stack 1210. Thus, the monitoring portion 1010 is electrically connected to the battery stack 1210 via the wiring portion 1030.

[0217] A connector (not shown) is placed on the wiring substrate 1011 . Fig.17The monitoring portion 1010 and the battery ECU 1300 are electrically connected via the wire 1301.

[0218] The wiring portion 1030 has a front wiring portion 1031 and a rear wiring portion 1032. Each of the front wiring portion 1031 and the rear wiring portion 1032 includes a flexible substrate 1033 having flexibility and a plurality of wiring patterns 1034 formed on the flexible substrate 1033.

[0219] The plurality of wiring patterns 1034 are connected to the series terminal 1223 and the output terminal 1224. A plurality of substrate wirings 14 are formed on the wiring substrate 1011 according to each of the plurality of wiring patterns 1034. These plurality of wiring patterns 1034 and the plurality of substrate wirings 14 are electrically connected.

[0220] Hereinafter, in order to simplify the description, the wiring pattern 1034 and the substrate wiring 1014 electrically connected to each other are collectively referred to as a voltage detection line.

[0221] like Fig.17 As shown, the second electronic component 60 is mounted on the flexible substrate 1033. The second electronic component 60 has a fuse 1061 and an inductor 1062. The monitoring portion 1010 has a Zener diode 1015, a parallel capacitor 16, and a resistor 1017 as the first electronic component 1012. Each of the Zener diode 1015, the parallel capacitor 16, and the resistor 1017 is mounted on the wiring substrate 1011.

[0222] like Fig.17 As shown, a fuse 1061, an inductor 1062 and a resistor 1017 are placed in each of the plurality of voltage detection lines. The fuse 1061, the inductor 1062 and the resistor 1017 are sequentially connected in series from the battery cell 1220 to the monitoring IC chip 1013.

[0223] Each of the Zener diode 1015 and the parallel capacitor 16 is connected in parallel between two voltage detection lines arranged in order of potential. Specifically, the Zener diode 1015 and the parallel capacitor 16 are connected between the inductor 1062 and the resistor 1017 in the voltage detection line. The anode of the Zener diode 1015 is connected to the low potential side of the two adjacent voltage detection lines. The cathode of the Zener diode 1015 is connected to the high potential side of the two adjacent voltage detection lines.

[0224] In the connection configuration, the resistor 1017 and the parallel capacitor 16 form an RC circuit. The RC circuit and the inductor 1062 function as a filter for reducing noise during voltage detection.

[0225] The Zener diode 1015 has a structure in which a short circuit failure occurs when an overvoltage is applied from the battery module 1200. Specifically, the Zener diode 1015 has a structure in which a PN junction type IC chip is directly clamped by a pair of leads. Thus, for example, unlike a configuration in which an IC chip and leads are indirectly connected through a wire, the Zener diode 1015 can avoid an open circuit failure caused by a wire breakage due to an overvoltage.

[0226] The fuse 1061 is disconnected due to a large current flowing in the voltage detection line when an overvoltage causes a short-circuit failure of the Zener diode 1015. The rated current of the fuse 1061 is set to a standard of a large current flowing in the voltage detection line when an overvoltage causes a short-circuit failure of the Zener diode 1015. The disconnection of the fuse 1061 prevents a large current from flowing into the monitoring IC chip 1013.

[0227] like Fig.17 As shown, the monitoring IC chip 1013 has: a driver 1018 that performs signal processing such as amplification; and a switch 1019 according to each of the plurality of battery cells 1220. The switch 1019 controls the electrical connection between the two voltage detection lines arranged in order of potential. One end of the switch 1019 is connected to the wiring of the monitoring IC chip 1013 connected to one of the two voltage detection lines arranged in order of potential. The other end of the switch 1019 is connected to the wiring of the monitoring IC chip 1013 connected to the other of the two voltage detection lines arranged in order of potential. The switching control of the switch 1019 controls the charging / discharging of the battery cell 1220 electrically connected to the two voltage detection lines connected to the switch 1019.

[0228] The monitoring IC chip 1013 has a comparator 1020 that detects each voltage of a plurality of battery cells 1220. Two voltage detection lines arranged in order of potential are connected to the inverting input terminal and the non-inverting input terminal of the comparator 1020. Thus, the positive electrode terminal 1221 and the negative electrode terminal 1222 of one battery cell 1220 are connected to the inverting input terminal and the non-inverting input terminal of the comparator 1020. The output terminal of the comparator 1020 is connected to the wiring of the monitoring IC chip 1013. The battery ECU 1300 receives the output voltage of the comparator 1020 as a differential amplified output voltage (electromotive force) of one battery cell 1220.

[0229] The input impedance of the comparator 1020 is higher than the output impedance of the comparator 1020. Therefore, the amount of current flowing from the battery cell 1220 to the comparator 1020 is small. The current flowing from the battery cell 1220 to the comparator 1020 is smaller than the current flowing to the battery stack 1210 of the plurality of battery cells 1220 connected in series. The comparator 1020 corresponds to a voltage detection circuit.

[0230] There is a correlation between the state of charge (SOC) and the electromotive force of the battery cell 1220. The battery ECU 1300 stores the correlation. The battery ECU 1300 detects the SOC of each of the plurality of battery cells 1220 based on the stored correlation and the output voltage (electromotive force) input from the monitoring IC chip 1013.

[0231] The battery ECU 1300 determines the equalization process of the SOC of the plurality of battery cells 1220 based on the detection result. The battery ECU 1300 outputs an instruction of the equalization process to the driver 1018 of the monitoring IC chip 1013 based on the determination. The driver 1018 follows the instruction of the equalization process to perform switching control of the switch 19 according to each of the plurality of battery cells 1220. Thus, the plurality of battery cells 1220 are charged and discharged. The SOC of the plurality of battery cells 1220 is equalized.

[0232] The battery ECU 1300 detects the charging state of the battery stack 1210 based on the input voltage, etc. The battery ECU 1300 outputs the detected charging state of the battery stack 1210 to the vehicle-mounted ECU. The vehicle-mounted ECU outputs a command signal to the vehicle-mounted ECU based on the charging state and vehicle information input from various sensors installed on the vehicle, ignition switch, etc., such as the depression amount of the accelerator pedal, the throttle opening, etc. The battery ECU 1300 controls the connection between the battery stack 1210 and the electric load based on the command signal.

[0233] A system main relay (not shown) is placed between the battery stack 1210 and the electrical load. The system main relay controls the electrical connection between the battery stack 1210 and the electrical load by generating a magnetic field. The battery ECU 1300 controls the connection between the battery stack 1210 and the electrical load by controlling the generation of the magnetic field of the system main relay.

[0234] (Structure of the wiring part)

[0235] refer to Figures 19 to 21 , describing the configuration of the wiring portion 1030. The wiring portion 1030 has a front wiring portion 1031 and a rear wiring portion 1032. Each of the front wiring portion 1031 and the rear wiring portion 1032 has a flexible substrate 1033 and a plurality of wiring patterns 1034.

[0236] like Fig.19 As shown, the flexible substrate 1033 has a rectangular shape extending in the longitudinal direction. The length of the flexible substrate 1033 in the longitudinal direction is determined according to the length of the battery stack 1210 in the longitudinal direction.

[0237] The flexible substrate 1033 is thinner than the wiring substrate 1011 and is made of a flexible resin material. Therefore, the flexible substrate 1033 can be bent. That is, the flexible substrate 1033 is elastically deformable. The flexible substrate 1033 corresponds to a flexible substrate.

[0238] As shown in the drawings, a portion of the flexible substrate 1033 has a notch or bellows structure to greatly deform in the longitudinal and transverse directions. The flexible substrate 1033 may have a notch or hole that penetrates in the height direction to avoid obstructing wind flow in the accommodation space formed by the battery case.

[0239] The wiring pattern 1034 is formed on the front surface 1033a of the flexible substrate 1033. The coating resin covers the wiring pattern 1034. The tip of one end toward the wiring pattern 1034 protrudes toward the outside of each of the flexible substrate 1033 and the coating resin to be exposed. The tip of one end toward the wiring pattern 1034 is mechanically and electrically connected to the series terminal 1223 and the output terminal 1224 by welding or the like. The tip of the other end toward the wiring pattern 1034 is mechanically and electrically connected to the substrate wiring 1014 of the wiring substrate 1011 by solder or the like. The accompanying drawings show that the tip of one end toward the wiring pattern 1034 is placed on the flexible substrate 1033 to simplify the description.

[0240] The front wiring portion 1031 and the rear wiring portion 1032 have the same configuration. Therefore, the flexible substrate 1033 and the wiring pattern 1034 of the front wiring portion 1031, and the flexible substrate 1033 and the wiring pattern 1034 of the rear wiring portion 1032 have the same shape. The front wiring portion 1031 corresponds to the first wiring portion. The rear wiring portion 1032 corresponds to the second wiring portion.

[0241] (Installation form of front wiring section and rear wiring section)

[0242] The front wiring portion 1031 and the rear wiring portion 1032 have the same structure. However, the installation form of the front wiring portion 1031 and the rear wiring portion 1032 on the battery stack 1210 is different. Fig. 20As shown, the front wiring portion 1031 is mounted on the battery stack 1210 in a form in which the rear surface 1033b of the flexible substrate 1033 faces the upper end surface 1220a of the battery cell 1220. The rear wiring portion 1032 is mounted on the battery stack 1210 in a form in which the front surface 1033a of the flexible substrate 1033 faces the upper end surface 1220a. The front / rear of the front wiring portion 1031 and the rear wiring portion 1032 are reversed to each other and mounted on the battery stack 1210. Therefore, in the front wiring portion 1031 and the rear wiring portion 1032, the front / rear of each arrangement of the wiring pattern 1034 is reversed to each other. For example, when the arrangement of the front wiring pattern 1031 is reversed, the reversed arrangement corresponds to the arrangement of the rear wiring portion 1032.

[0243] The tip of one end toward the wiring pattern 1034 is exposed from each of the flexible substrate 1033 and the coating resin. Therefore, even when the front / rear of the flexible substrate 1033 is reversed, the flexible substrate 1033 or the coating resin is not located between the tip of one end toward the wiring pattern 1034 and the series terminal 1223 or the output terminal 1224. The flexible substrate 1033 or the coating resin is not located between the tip of the other end of the wiring pattern 1034 and the wiring substrate 1011.

[0244] The front wiring portion 1031 and the rear wiring portion 1032 are placed between the first electrode terminal group 1211 and the second electrode terminal group 1212 on the upper end surface 1220a of the plurality of battery cells 1220. The front wiring portion 1031 and the rear wiring portion 1032 are separated from each other in the lateral direction. The front wiring portion 1031 is positioned toward the first electrode terminal group 1211. The rear wiring portion 1032 is positioned toward the second electrode terminal group 1212.

[0245] The wiring pattern 1034 of the front wiring portion 1031 is connected to the series terminal 1223 and the output terminal 1224 that are mechanically and electrically connected to the electrode terminals constituting the first electrode terminal group 1211. The wiring pattern 1034 of the rear wiring portion 1032 is connected to the series terminal 1223 and the output terminal 1224 that are mechanically and electrically connected to the electrode terminals constituting the second electrode terminal group 1212.

[0246] As described above, the wiring portion 1030 and the battery stack 1210 have Fig.17 The wiring portion 1030 can detect the voltages of all the battery cells 1220 constituting the battery stack 1210 .

[0247] (Connection structure)

[0248] refer to Fig.19 and Fig. 20, describing the connection structure of the wiring diagram 1034. The connection structure connects the series terminal 1223 and the output terminal 1224 to the wiring substrate 1011.

[0249] The wiring pattern 1034 has: a plurality of first wirings 1035, the plurality of first wirings 1035 are connected to the series terminal 1223; a plurality of second wirings 36, the plurality of second wirings 36 are connected to the positive electrode terminal 1221 and the negative electrode terminal 1222 of two battery cells 1220, the positive electrode terminal 1221 and the negative electrode terminal 1222 are located at both ends of the plurality of battery cells 1220 arranged in the longitudinal direction. In this embodiment, specifically, the second wiring 1036 is connected to the output terminal 1224. The first wiring 1035 corresponds to the series wiring pattern. The second wiring 1036 corresponds to the two-end wiring pattern.

[0250] like Fig. 20 As shown, the plurality of first wirings 1035 are located between the two second wirings 36. Each of one end of the plurality of first wirings 1035 and the two second wirings 36 extends toward the electrode terminal group. Each of the other ends of the plurality of first wirings 1035 and the two second wirings 36 extends toward the wiring substrate 1011. One end of the first wiring 1035 is connected to the series terminal 1223. One end of the second wiring 1036 is connected to the output terminal 1224. Each of the other ends of the first wiring 1035 and the second wiring 1036 is connected to the wiring substrate 1011.

[0251] The flexible substrate 1033 has a plurality of first protrusions 1037 and two second protrusions 1038, and the plurality of first protrusions 1037 and the two second protrusions 1038 extend toward the electrode terminal group. One end of the first wiring 1035 is placed on the first protrusion 1037. One end of the second wiring 1036 is placed on the second protrusion 1038. The tip of one end toward the first wiring 1035 is exposed from the first protrusion 1037. The tip of one end toward the second wiring 1036 is exposed from the second protrusion 1038.

[0252] The two second protrusions 1038 are arranged to be separated from each other in the longitudinal direction. The plurality of first protrusions 1037 are located between the two second protrusions 1038. The plurality of first protrusions 1037 are also arranged to be separated from each other in the longitudinal direction.

[0253] Due to the longitudinal arrangement of the protrusions, a first protrusion 1037 and a second protrusion 1038 located at the end of a plurality of first protrusions 1037 arranged in the longitudinal direction are arranged adjacent to each other in the longitudinal direction. Two adjacent battery cells 1220 arranged in the longitudinal direction include electrode terminals with different poles. The separation distance in the longitudinal direction between these first protrusions 1037 and these second protrusions 1038 is equal to the separation distance between the electrode terminals with different poles. That is, the separation distance in the longitudinal direction between the first protrusion 1037 and the second protrusion 1038 is equal to the distance between the positive electrode terminal 1221 of one of the two adjacent battery cells 1220 arranged in the longitudinal direction and the negative electrode terminal 1222 of the other of the two adjacent battery cells 1220.

[0254] The two battery cells 1220 sandwiching one battery cell 1220 are arranged in the longitudinal direction and include electrode terminals having the same polarity.

[0255] A separation distance between two first protrusions 1037 arranged adjacent to each other in the longitudinal direction is equal to a separation distance between electrode terminals having the same polarity.

[0256] That is, the separation distance between two adjacent first protrusions 1037 arranged in the longitudinal direction is equal to the separation distance between the positive electrode terminal 1221 of one of two adjacent battery cells 1220 that clamp one battery cell 1220 and are arranged in the longitudinal direction and the positive electrode terminal 1221 of the other of the two adjacent battery cells 1220.

[0257] That is, the separation distance between two adjacent first protrusions 1037 arranged in the longitudinal direction is equal to the separation distance between the negative electrode terminal 1222 of one of the two adjacent battery cells 1220 clamping one battery cell 1222 and the negative electrode terminal 1222 of the other of the two adjacent battery cells 1220 .

[0258] In the following, in order to avoid complication of the description, the separation distance in the longitudinal direction between the first protrusion 1037 and the second protrusion 1038 arranged adjacent to each other in the longitudinal direction may be referred to as the output separation distance. The longitudinal separation distance between two adjacent first protrusions 1037 arranged in the longitudinal direction may be referred to as the serial separation distance. Generally, the output separation distance is about half of the serial separation distance. The output separation distance is about the longitudinal length of one battery cell 1220. The serial separation distance is about the longitudinal length between two adjacent battery cells 1220 arranged in the longitudinal direction.

[0259] like Fig. 20As shown, one of the two second protrusions 1038 of the front wiring portion 1031 is connected to the output terminal 1224 connected to the positive electrode terminal 1221 of No. 17 in the first electrode terminal group 1211. However, the remaining one of the two second protrusions 1038 of the front wiring portion 1031 is not connected. The second protrusion 1038 that has no effect on this connection can be omitted, for example Fig.21 shown.

[0260] Similarly, one of the two second protrusions 1038 of the rear wiring portion 1032 is connected to the output terminal 1224 connected to the negative electrode terminal 1222 of No. 0 in the second electrode terminal group 1212. However, the remaining one of the two second protrusions 1038 of the rear wiring portion 1032 is not connected. The second protrusion 1038 that does not contribute to such a connection can be omitted in a similar manner.

[0261] The front wiring portion 1031 and the rear wiring portion 1032 have an additional second protrusion 1038 that has no effect on the connection. Since one of the front wiring portion 1031 and the rear wiring portion 1032 is connected to one of the two output terminals 1224 separated in the longitudinal direction, each of the front wiring portion 1031 and the rear wiring portion 1032 has such an additional second protrusion 1038. The other of the front wiring portion 1031 and the rear wiring portion 1032 is connected to the other of the two output terminals separated in the longitudinal direction.

[0262] However, since the number of three or more battery cells 1220 of the battery stack 1210 is an odd number, the front wiring portion 1031 and the rear wiring portion 1032 have an additional second protrusion 1038 that has no effect on the connection. When the number of three or more battery cells 1220 of the battery stack 1210 is an even number, the two second protrusions 1038 of the front wiring portion 1031 have no effect on the connection. The two second protrusions 1038 retained by the rear wiring portion 1032 facilitate the connection. Regardless of whether the number of three or more battery cells 1220 of the battery stack 1210 is an odd number or an even number, the front wiring portion 1031 and the rear wiring portion 1032 can be connected to the two output terminals 1224.

[0263] The flexible substrate 1033 has a protruding portion 1039 extending toward the monitoring portion 1010. The other end of the wiring pattern 1034 is placed on the protruding portion 1039. The tip of the other end toward the wiring pattern 1034 is exposed to the outside of the protruding portion 1039. The tip of the other end toward the wiring pattern 1034 is connected to the substrate wiring 1014 formed on the front surface 11a of the wiring substrate 1011. At the same time, the protruding portion 1039 is connected to the front surface 11a of the wiring substrate 1011.

[0264] The tip and the protruding portion 1039 of the other end of the wiring pattern 1034 may be connected to the rear surface which is the rear side of the front surface 11a of the wiring substrate 1011. In addition, the tip and the protruding portion 1039 of the other end of the wiring pattern 1034 toward the front wiring portion 1031 may be connected to one of the front surface 11a and the rear surface of the wiring substrate 1011. In addition, the tip and the protruding portion 1039 of the other end of the wiring pattern 1034 toward the rear wiring portion 1032 may be connected to the other of the front surface 11a and the rear surface of the wiring substrate 1011.

[0265] A configuration may be adopted in which the tip of the other end toward the wiring pattern 1034 is not exposed to the outside of the protruding portion 1039. In this case, a through hole for electrically connecting the other end of the wiring pattern 1034 to the substrate wiring 1014 is formed in the protruding portion 1039. The through hole is used to electrically connect the front surface 1033a and the rear surface 1033b of the flexible substrate 1033 constituting the protruding portion 1039. The through hole is electrically connected to the substrate wiring 1014. Thus, the wiring pattern 1034 is electrically connected to the substrate wiring 1014 through the through hole.

[0266] (Structure of series terminals)

[0267] refer to Fig.18 and Fig. 22 , describing the construction of the series terminal 1223.

[0268] The series terminal 1223 has a thin flat shape in the height direction. The series terminal 1223 has a first connection surface 1223a and a second connection surface 1223b facing the height direction. The series terminal 1223 connected to the electrode terminal constituting the first electrode terminal group 1211 and the series terminal 1223 connected to the electrode terminal constituting the second electrode terminal group 1212 have the same structure. However, the two series terminals 1223 have different connection forms with the battery stack 1210.

[0269] like Fig.18As shown, the series terminal 1223 connected to the electrode terminals constituting the first electrode terminal group 1211 is connected to the battery stack 1210 in a form in which the second connection surface 1223b faces the upper end surface 1220a. The series terminal 1223 connected to the electrode terminals constituting the second electrode terminal group 1212 is connected to the battery stack 1210 in a form in which the first connection surface 1223a faces the upper end surface 1220a. The series terminal 1223 connected to the electrode terminals constituting the first electrode terminal group 1211 and the series terminal 1223 connected to the electrode terminals constituting the second electrode terminal group 1212 have opposite connection surfaces connected to the battery stack 1210. In other words, the connection surface of the first electrode terminal group 1211 on the battery stack 1210 is opposite to the connection surface of the second electrode terminal group 1212 on the battery stack 1210.

[0270] like Fig. 22 As shown, the series terminal 1223 has a connecting portion 1225 and a connecting portion 1226, which are integrally connected. The connecting portion 1225 connects the positive electrode terminal 1221 with the negative electrode terminal 1222. The connecting portion 1226 is connected to a tip protruding from the first protrusion 1037 toward one end of the first wiring 1035. Therefore, the connecting portion 1226 is connected to the input terminal of the comparator 1020 having a high input impedance through the first wiring 1035, the substrate wiring 1014, and the wiring of the monitoring IC chip 1013.

[0271] Due to the connection configuration, the current flows in the connection portion 1225, and the current flowing in the battery stack 1210 is connected in series with the plurality of battery cells 1220. A small amount of current flows in the connection portion 1226 compared to the current flowing in the connection portion 1225. Hereinafter, the current flowing in the connection portion 1225 may be referred to as the main current I in order to simplify the description. The current flowing in the connection portion 1226 may be referred to as the detection current j.

[0272] The connecting portion 1225 has a rectangular shape extending in the longitudinal direction. The longitudinal length of the connecting portion 1225 is the above-mentioned serial separation distance. The positive electrode terminal 1221 is connected to one of the two ends in the longitudinal direction of the connecting portion 1225. The negative electrode terminal 1222 is connected to the other end of the two ends in the longitudinal direction of the connecting portion 1225.

[0273] exist Fig. 22In order to clarify the connection position of each of the positive terminal 1221 and the negative terminal 1222 in the connecting portion 1225, the positive terminal 1221 and the negative terminal 1222 are represented by circles. The center point connected to the positive electrode terminal 1221 and the center point connected to the negative electrode terminal 1222 in the connecting portion 1225 are represented by dots. Hereinafter, the center point connected to the positive electrode terminal 1221 in the connecting portion 1225 is referred to as the first center point CP1. The center point connected to the negative electrode terminal 1222 in the connecting portion 1225 is referred to as the second center point CP2. The first center point CP1 corresponds to the first connecting portion. The second center point CP2 corresponds to the second connecting portion.

[0274] In a state where the connecting portion 1225 is connected to the positive electrode terminal 1221 and the negative electrode terminal 1222, the connecting portion 1226 faces separately from the region between the positive electrode terminal 1221 and the negative electrode terminal 1222 on the upper end surface 1220a of the plurality of battery cells 1220 in the height direction. The connecting portion 1226 has a reference portion 1227 extending laterally from the connecting portion 1225. The length of the reference portion 1227 in the longitudinal direction is longer than the length of the connecting portion 1225. The connecting portion 1226 has a compensation portion 1228 extending in the longitudinal direction from the tip (also referred to as the end) of the reference portion 1227. The upper end surface 1220a corresponds to the forming surface.

[0275] like Fig. 22 As shown, the reference portion 1227 extends in the lateral direction from the midpoint MP between the first center point CP1 and the second center point CP2 of the connecting portion 1225. The separation distance between the end of the reference portion 1227 and the first center point CP1 is equal to the separation distance between the end of the reference portion 1227 and the second center point CP2, the end extending from the connecting portion 1225. Due to this configuration, the resistance value of the first resistor between the first center point CP1 of the connecting portion 1225 and the end of the reference portion 1227 is equal to the resistance value of the second resistor between the second center point CP2 in the connecting portion 1225 and the end of the reference portion 1227.

[0276] As described above, each of the series terminals 1223 connected to the electrode terminals constituting the first electrode terminal group 1211 and the series terminals 1223 connected to the electrode terminals constituting the second electrode terminal group 1212 has opposite connection surfaces connected to the battery stack 1210. Therefore, in the two series terminals 1223, each of the first center point CP1 and the second center point CP2 is reversed and replaced. However, in the two series terminals 1223, the separation distance between the end of the reference portion 1227 and the first center point CP1 in the connecting portion 1225 is equal to the separation distance between the end of the reference portion 1227 and the second center point CP2. Therefore, even if the first center point CP1 and the second center point CP2 are replaced, the resistance values ​​of the first resistor and the second resistor are still equal to each other in the two series terminals.

[0277] Hereinafter, resistance values ​​of the first resistor and the second resistor may be defined as R. To simplify description, a resistance value of the reference portion 1227 extending in the lateral direction may be defined as R. The resistance values ​​of the first resistor and the second resistor may be different from the resistance value of the reference portion 1227 .

[0278] The compensation portion 1228 extends from the tip of the reference portion 1227 in the longitudinal direction in a form in which the compensation portion 1228 is maintained by one side of the reference portion 1227. Therefore, the connection portion 1226 in this embodiment has an L shape on the upper end surface 1220a. The longitudinal length of the compensation portion 1228 is approximately the above-mentioned output separation distance. The compensation portion 1228 is connected to the tip of one end protruding from the first protrusion 1037 toward the first wiring 1035.

[0279] Hereinafter, the resistance value of the compensation portion 1228 may be defined as 2R. In the compensation portion 1228 extending in the longitudinal direction, as shown in FIG. Fig. 22 As shown, two resistors of resistance value R are connected in series in the longitudinal direction. There are three endpoints at both ends of the two resistors connected in series. When the endpoint moves away from the tip of the reference portion 1227, the three endpoints are represented as a first endpoint EP1, a second endpoint EP2, and a third endpoint EP3 in the order of increasing numbers. One of the two resistors is located between the first endpoint EP1 and the second endpoint EP2. The remaining one of the two resistors is located between the second endpoint EP2 and the third endpoint EP3.

[0280] As described above, each of the series terminals 1223 connected to the electrode terminals constituting the first electrode terminal group 1211 and the series terminals 1223 connected to the electrode terminals constituting the second electrode terminal group 1212 has opposite connection surfaces connected to the battery stack 1210. The extension direction of the compensation portion 1228 in the series terminal 1223 connected to the electrode terminals constituting the first electrode terminal group 1211 and the extension direction of the compensation portion 1228 in the series terminal 1223 connected to the electrode terminals constituting the second electrode terminal group 1212 are opposite.

[0281] Specifically, the compensation portion 1228 in the series terminal 1223 connected to the electrode terminals constituting the first electrode terminal group 1211 extends to the high potential side of the battery stack 1210. Specifically, the compensation portion 1228 in the series terminal 1223 connected to the electrode terminals constituting the second electrode terminal group 1212 extends to the low potential side of the battery stack 1210. In other words, the compensation portion 1228 in the series terminal 1223 connected to the electrode terminals constituting the first electrode terminal group 1211 extends to be separated from the monitoring portion 1010. The compensation portion 1228 in the series terminal 1223 connected to the electrode terminals constituting the second electrode terminal group 1212 extends to approach the monitoring portion 1010.

[0282] Therefore, in the compensation part 1228 of the series terminal 1223 connected to the electrode terminal constituting the first electrode terminal group 1211, the first end point EP1, the second end point EP2, and the third end point EP3 are arranged in the order of the direction in which the end points are separated from the monitoring part 1010 in the length direction. In the compensation part 1228 of the series terminal 1223 connected to the electrode terminal constituting the second electrode terminal group 1212, the first end point EP1, the second end point EP2, and the third end point EP3 are arranged in the order of the direction in which the end points are close to the monitoring part 1010 in the longitudinal direction.

[0283] (Voltage drop across series terminals)

[0284] The voltage drop occurring in the series terminal 1223 will be described below.

[0285] In the above connection structure, the voltage of the battery cell 1220 is input to the comparator 1020 through the series terminal 1223, the first wiring 1035, the substrate wiring 1014, and the wiring of the monitoring IC chip 1013. Each of the series terminal 1223, the first wiring 1035, the substrate wiring 1014, and the wiring of the monitoring IC chip 1013 has resistance. Therefore, a voltage drop occurs in the power-on path connecting the battery cell 1220 and the comparator 1020.

[0286] One end of the first wiring 1035 is connected to the series terminal 1223. When the connection position of the series terminal 1223 and the first wiring 1035 is equal to the connection position between the plurality of series terminals 1223 and the plurality of first wirings 1035, the voltage drop occurring due to the current flowing in the resistance of the series terminal 1223 may be comparable. Therefore, it may be difficult to change the detection accuracy of the voltage detected in the plurality of first wirings 1035 of the battery cell 1220.

[0287] However, when the position connected to one end of the first wiring 1035 in the series terminal 1223 is changed, the voltage drop caused by the flowing current and the resistance of the series terminal 1223 changes. As a result, the detection accuracy of the voltage detected in the plurality of first wirings 1035 of the battery cell 1220 may change. The displacement of the connection position is caused by unclear definition of the connection position of the wiring portion 1030 and the battery stack 1210 or layout deviation.

[0288] In contrast, the series terminal 1223 in the present embodiment has not only the linking portion 1225 but also the connecting portion 1226. One end of the first wiring 1035 is connected to the connecting portion 1226 extending from the midpoint MP of the linking portion 1225. The connection point of the first wiring 1035 is defined by the connecting portion 1226. Therefore, each voltage drop occurring due to the resistance and current of the connecting portion 1226 is equal, and the voltage drop is included in the voltage of the battery cell 1220 detected by each of the plurality of first wirings 1035. As a result, it is possible to prevent the occurrence of variations in the detection accuracy of the voltage of the battery cell 1220 detected in the plurality of first wirings 1035.

[0289] The connection portion 1226 includes a reference portion 1227 extending in the lateral direction from the connection portion 1225, and a compensation portion 1228 extending in the longitudinal direction from the tip of the reference portion 1227. The compensation portion 1228 is connected to one end of the first wiring 1035. Therefore, even if one end of the first wiring 1035 deviates in the longitudinal direction from the series terminal 1223 of the connection target due to the arrangement deviation of the wiring portion 1030 relative to the battery stack 1210, the first wiring 1035 can be connected to the series terminal 1223.

[0290] The detection current j flowing in the connection portion 1226 connected to one end of the first wiring 1035 is smaller than the main current I flowing in the connection portion 1225. Therefore, the amount of voltage drop that occurs due to the current and resistance of the connection portion 1226 is small, and the voltage drop is included in the detection voltage of the battery cell 1220 in the first wiring 1035. Therefore, even when the connection position of the first wiring 1035 and the connection portion 1226 deviates, the change in the detection accuracy of the detection voltage of the battery cell 1220 in the plurality of first wirings 1035 is small. Thus, the change in the detection accuracy of the voltage of the battery cell 1220 detected in each of the plurality of first wirings 1035 can be prevented from occurring.

[0291] Hereinafter, with respect to a case where there is a deviation in arrangement of the wiring portion 1030 relative to the battery stack 1210 and a case where there is no deviation in arrangement of the wiring portion 1030 relative to the battery stack 1210, reference will be made to Figure 23 to Figure 25 , specifically describing the voltage drop occurring in the series terminal 1223. Figure 23 to Figure 25 It is shown that the series terminal 1223 connects the positive electrode terminal 1221 of No. 1 and the negative electrode terminal 1222 of No. 2. The positive electrode terminal 1221 of No. 1 and the negative electrode terminal 1222 of No. 2 constitute the first electrode terminal group 1211. Figure 23 to Figure 25 It is shown that the series terminal 1223 connects the positive electrode terminal 1221 of No. 3 and the negative electrode terminal 1222 of No. 4. The positive electrode terminal 1221 of No. 3 and the negative electrode terminal 1222 of No. 4 constitute the second electrode terminal group 1212.

[0292] Hereinafter, to simplify the description, the series terminal 1223 connecting the positive electrode terminal 1221 of No. 1 with the negative electrode terminal 1222 of No. 2 may be referred to as the first series terminal 1223. The series terminal 1223 connecting the positive electrode terminal 1221 of No. 3 with the negative electrode terminal 1222 of No. 4 may be referred to as the second series terminal 1223.

[0293] The first series terminal 1223 and the second series terminal 1223 are connected to the positive electrode terminal 1221 and the negative electrode terminal 1222 of the battery cell 1220 having the second lowest potential among the plurality of battery cells 1220 arranged in order of potential. The first series terminal 1223 is connected to the negative electrode terminal 1222 of the battery cell 1220. The second series terminal 1223 is connected to the positive electrode terminal 1221 of the battery cell 1220. Therefore, the potential difference between the first series terminal 1223 and the second series terminal 1223 corresponds to the output voltage of the battery cell 1220. Hereinafter, the battery cell 1220 having the second lowest potential may be referred to as just the battery cell 1220.

[0294] Fig.23FIG. 1 shows a connection form between the wiring portion 1030 and the series terminal 1223 when there is no arrangement deviation of the wiring portion 1030 relative to the battery stack 1210. Fig.23 In one example shown, the second end point EP2 of the first series terminal 1223 is connected to one end of the first wiring 1035 of the front wiring portion 1031. Similarly, the second end point EP2 of the second series terminal 1223 is connected to one end of the first wiring 1035 of the rear wiring portion 1032. Therefore, the voltage drop included in the voltage detected in the two first wirings 1035, which occurs due to the current and resistance of the series terminals, is equal.

[0295] The potential of the negative electrode terminal 1222 of the battery cell 1220 and the potential of the positive electrode terminal 1221 of the battery cell 1220 have an equal voltage drop and are input to the inverting input terminal and the non-inverting input terminal of the comparator 1020. The comparator 1020 subtracts the potential input of the inverting input terminal and the potential input of the non-inverting input terminal, and outputs an output signal as the output voltage Vo of the battery cell 1220 according to the voltage value obtained by the subtraction. Fig.24 FIG. 1 shows a connection form between the wiring portion 1030 and the series terminal 1223 when there is a deviation in the arrangement of the wiring portion 1030 relative to the battery stack 1210. Fig.24 In the example shown, the connection point between the first series terminal 1223 and one end of the first wiring 1035 of the front wiring portion 1031 is offset. The third end point EP3 of the first series terminal 1223 is connected to one end of the first wiring 1035 of the front wiring portion 1031. The second end point EP2 of the second series terminal 1223 is connected to one end of the first wiring 1035 of the rear wiring portion 1032.

[0296] Compared to the main current I flowing in the connecting portion 1225 as described above, a small amount of detection current j flows in the connecting portion 1226. The resistance value between the second terminal EP2 and the third terminal EP3 is R. Therefore, the voltage drop included in the voltage detected in the two first wirings 1035 due to the current and resistance of the series terminal 1223 is different by -jR. Therefore, when the amplification degree of the comparator 1020 is 1 to simplify the description, as shown in FIG. Fig.24 As shown, comparator 1020 outputs Vo+jR.

[0297] As described above, the detection current j is small. Therefore, the voltage drop jR is small. Therefore, even when a deviation of the connection point occurs, a change in the detection accuracy of the voltage detected in the plurality of first wirings 1035 of the battery cell 1220 can be prevented from occurring.

[0298] As a comparison construct, Fig.25The configuration in which the first series terminal 1223 and the second series terminal 1223 have only the connecting portion 1225 is shown. Even when there is a deviation in the arrangement of the wiring portion 1030 relative to the battery stack 1210, the midpoint MP of the connecting portion 1225 of the first series terminal 1223 is connected to one end of the first wiring 1035 of the front wiring portion 1031. The midpoint MP of the connecting portion 1225 of the second series terminal 1223 is connected to one end of the first wiring 1035 of the rear wiring portion 1032. In this case, the voltage drops of the voltages detected in the two first wirings 1035 are equal.

[0299] However, when there is a deviation in the arrangement of the wiring portion 1030 relative to the battery stack 1210, for example, Fig.25 As shown, one end of the first wiring 1035 of the front wiring part 1031 is connected to the first center point CP1 of the connecting part 1225 of the first series terminal 1223. The midpoint MP of the connecting part 1225 of the second series terminal 1223 is connected to one end of the first wiring 1035 of the rear wiring part 1032.

[0300] Compared with the detection current j flowing in the connection portion 1226 as described above, a large amount of the main current I flows in the connection portion 1225. The resistance value between the first center point CP1 and the midpoint MP is R. Therefore, the voltage drop included in the voltage detected in the two first wirings 1035 due to the current and resistance of the series terminal 1223 differs by -IR. In this case, as Fig.25 As shown, comparator 1020 outputs Vo+IR.

[0301] As described above, the main current is large. The voltage drop IR is large. Therefore, in the comparative configuration, even when a deviation of the connection point occurs, a change in the detection accuracy of the voltage of the battery cell 1220 detected in the plurality of first wirings 1035 becomes large.

[0302] In the case of the series terminal 1223 of the present embodiment, as described above, the voltage drop jR occurring due to the deviation of the connection point is small, and therefore, the variation in the detection accuracy of the voltage detected in the plurality of first wirings 1035 of the battery cell 1220 can be prevented from occurring.

[0303] like Fig.26A and Fig.26B As shown, the detailed form of the series terminal 1223 is not limited to the structure in this embodiment. Fig.26AAs shown, the compensation portion 1228 extends longitudinally from the tip of the reference portion 1227. Thus, it is possible to adopt a configuration in which the connection portion 1226 has a T-shape on the upper end surface 1220a. Thus, even if one end of the first wiring 1035 deviates in the longitudinal direction from the series terminal 1223 as the connection target in the direction toward the monitoring portion 1010 or away from the monitoring portion 1010, the first wiring 1035 can be connected to the series terminal 1223.

[0304] A construction may be adopted in which, for example Fig.26B As shown, the connection portion 1226 of the series terminal 1223 has only the reference portion 1227. In this configuration, the tip of the reference portion 1227 is connected to one end of the first wiring 1035. Thus, the voltage drop included in the voltage detected in each of the plurality of first wirings 1035 of the battery cell 1220 can be made equal. Even when the connection position of one end of the first wiring 1035 deviates from the reference portion 1227, the voltage drop caused by the deviation is small.

[0305] exist Fig.26B In the case of the configuration shown, the length of each of the first protrusion 1037, the second protrusion 1038, the portion toward one end of the first wiring 1035, and the portion toward one end of the second wiring 1036 is long, so that it can be bent in the longitudinal direction and the lateral direction. Thus, even when there is a layout deviation of the wiring portion 1030 relative to the battery stack 1210, the first protrusion 1037 and one end of the first wiring 1035 are bent toward the reference portion 1227 of the series terminal 1223 as the connection target. The second protrusion 1038 and one end of the second wiring 1036 are bent toward the output terminal 1224 as the connection target. Thus, the tip of the reference portion 1227 of the series terminal 1223 can be connected to one end of the first wiring 1035. The tip of the output terminal 1224 can be connected to one end of the second wiring 1036.

[0306] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments and may be implemented in various modified examples without departing from the scope of the present disclosure.

[0307] (Eighth Modification)

[0308] In this embodiment, the monitoring IC chip 1013 is illustrated as having a comparator 1020. For example, the detection current j is smaller than the main current I generated by the connection between the input terminal of the comparator 1020 and the series terminal 1223. In the configuration of this embodiment, the number of comparators 1020 is required to be the same as the number of battery cells 1220.

[0309] On the contrary, in addition to the comparator 1020, a configuration in which the monitoring IC chip 1013 has a sampling and holding circuit and a multiplexer can be adopted. The sampling and holding circuit has: a switch placed in each of a plurality of voltage detection lines arranged in order of potential; and a capacitor located on the rear side relative to these switches and connected in parallel to the voltage detection lines arranged in order of potential. The capacitance of the capacitor is very small. By closing the switch, the detection current j is very small and flows into the capacitor. Afterwards, the switch is opened. Thus, the capacitor stores charge according to the detection current j.

[0310] The multiplexer is located at the rear stage relative to the capacitor. The multiplexer is connected to a plurality of voltage detection lines. The multiplexer selects two of the plurality of voltage detection lines and connects the selected voltage detection lines to the comparator 1020. Thus, the detection current j flows from the capacitor to the comparator 1020. In the case of this variation, the capacitance of the capacitor of the sampling and holding circuit is very small. The detection current j is less than the main current I. The number of comparators 1020 can be less than the number of battery cells 1220.

[0311] (Ninth Modification)

[0312] In this embodiment, the shape of the output terminal 1224 is not described in detail. Fig.18 As shown, the shape of the output terminal 1224 can have, for example, a rectangular shape extending in the transverse direction at a position facing the longitudinal direction. Similarly, in the series terminal 1223 shown in this embodiment, the output terminal 1224 can have a connecting portion connected to one electrode terminal and a connecting portion extending from the connecting portion.

[0313] (Tenth Modification)

[0314] In the present embodiment, the wiring pattern 1034 is placed on the front surface 1033a. However, a configuration in which the wiring pattern 1034 is placed on the rear surface 1033b may be adopted.

[0315] (Eleventh Modification)

[0316] In the present embodiment, the wiring portion 1030 is illustrated as including the front wiring portion 1031 and the rear wiring portion 1032 having the same structure. However, the front wiring portion 1031 and the rear wiring portion 1032 may not have the same structure. Fig. 27 As shown, the front wiring portion 1031 has a configuration of the first protrusion 1037, the second protrusion 1038, and the wiring pattern 1034 according to the first electrode terminal group 1211. The rear wiring portion 1032 may also have a configuration of the first protrusion 1037, the second protrusion 1038, and the wiring pattern 1034 according to the second electrode terminal group 1212. Fig. 27In the embodiment, the rear wiring portion 1032 is mounted on the battery stack 1210 in a manner that the rear surface 1033b of the flexible substrate 1033 faces the upper end surface 1220a of the battery cell 1220. A structure in which the front wiring portion 1031 and the rear wiring portion 1032 are integrally connected may also be adopted (not shown).

[0317] (Twelfth Modification)

[0318] In the present embodiment, the battery stack 1210 is illustrated as having nine battery cells 1220 . However, the number of battery cells 1220 of the battery stack 1210 is not limited to the above example and may be plural. The battery stack 1210 may have an even number of battery cells 1220 .

[0319] In the present embodiment, it is illustrated that the battery module 1200 has one battery stack 1210. However, the battery module 1200 may have a plurality of battery stacks 1210. In this case, the housing of the battery module 1200 includes an accommodation space according to each battery stack 1210. These plurality of accommodation spaces are arranged in the lateral direction.

[0320] For example, when the battery cells 1220 of two battery stacks 1210 are connected in series, each of the two battery stacks 1210 has the same even number of battery cells 1220. The multiple battery cells 1220 of each of the two battery stacks 1210 are arranged in the longitudinal direction. The wiring electrically connects the negative electrode terminal 1222 of the battery cell 1220 located at the longitudinal right end of one of the two battery stacks 1210 with the positive electrode terminal 1221 of the battery cell 1220 located at the right end of the other of the two battery stacks 1210. Therefore, the negative electrode terminal 1222 of the battery cell 1220 located at the longitudinal left end of one of the two battery stacks 1210 has the lowest potential. The positive electrode terminal 1221 of the battery cell 1220 located at the left end of the other of the two battery stacks 1210 has the highest potential. The positive electrode terminal 1221 with the highest potential and the negative electrode terminal 1222 with the lowest potential are arranged to be arranged in the transverse direction. The wiring portion 1030 is placed on each of the two battery stacks 1210 .

[0321] (Other Modifications)

[0322] In the present embodiment, the battery pack 1400 is applied to a hybrid vehicle, but the battery pack 1400 may be applied to, for example, a plug-in hybrid vehicle and an electric vehicle.

Claims

1. A monitoring device, include: A monitoring portion (10) configured to monitor a voltage of each of a plurality of battery cells (220) connected in series, each of the battery cells having electrode terminals (221, 222); as well as a wiring portion (30) for electrically connecting the monitoring portion and the electrode terminals of the battery cell (220), in, The wiring portion has a first flexible substrate (33) and a second flexible substrate (34), the first flexible substrate (33) and the second flexible substrate (34) having flexibility and being integrally connected to each other, The connection portion where the first flexible substrate and the second flexible substrate are connected is bent, The first flexible substrate is connected to the electrode terminal. The second flexible substrate is connected to the monitoring part, One of the first flexible substrate and the second flexible substrate has an arm (37); The other of the first flexible substrate and the second flexible substrate, except the one having the arm, has a slit (36); The arm is fixed to the slit, so that the connection is strengthened.

2. The monitoring device according to claim 1, It is characterized in that The second flexible substrate has the arm; The first flexible substrate has the slit.

3. The monitoring device according to claim 1, It is characterized in that Also includes: A substrate (31), wherein the substrate (31) comprises the first flexible substrate and the second flexible substrate, and the substrate is flexible; as well as a wiring pattern (32), wherein the wiring pattern (32) is arranged on the substrate, in, The arm has a reinforcing material (40) that is harder than the material from which the base plate is formed.

4. The monitoring device according to claim 1, It is characterized in that The battery cells are arranged along a first direction, Each of the battery cells comprises a forming surface (220a), The electrode terminals of each of the battery cells include a positive electrode terminal (221) and a negative electrode terminal (222), the positive electrode terminal and the negative electrode terminal are arranged in a second direction intersecting the first direction, The positive electrode terminals of the first cells of the battery cells and the negative electrode terminals of the second cells of the battery cells are alternately arranged in the first direction, which constitutes: A first electrode terminal group (211), in which the positive electrode terminals and the negative electrode terminals are arranged alternately; as well as a second electrode terminal group (212), in which the positive electrode terminals and the negative electrode terminals are alternately arranged in an order opposite to that of the first electrode terminal group, The electrode terminal is disposed on the formation surface, The first flexible substrate faces the forming surface, The first flexible substrate is placed between the first electrode terminal group and the second electrode terminal group. The monitoring portion and the second flexible substrate are placed on a side surface (220e) of the battery cell located at an end of the battery cells arranged along the first direction.

5. The monitoring device according to claim 1, It is characterized in that The battery cells are arranged along a first direction, Each of the battery cells comprises a forming surface (220a), The electrode terminals of each of the battery cells include a positive electrode terminal (221) and a negative electrode terminal (222), the positive electrode terminal and the negative electrode terminal are arranged in a second direction intersecting the first direction, The positive electrode terminals of the first cells of the battery cells and the negative electrode terminals of the second cells of the battery cells are alternately arranged in the first direction, which constitutes: A first electrode terminal group (211), in which the positive electrode terminals and the negative electrode terminals are arranged alternately; a second electrode terminal group (212), in which the positive electrode terminals and the negative electrode terminals are alternately arranged in an order opposite to that of the first electrode terminal group, The second flexible substrate is bent, The electrode terminal is disposed on the formation surface, The first flexible substrate, the second flexible substrate, and the monitoring portion are disposed between the first electrode terminal group and the second electrode terminal group and overlap each other on the formation surface.

6. The monitoring device according to any one of claims 1 to 5, It is characterized in that The monitoring part includes a wiring substrate (11) connected to the second flexible substrate, The monitoring part also includes a monitoring IC chip (13) placed on the wiring substrate.

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