POWER STORAGE DEVICE AND METHOD FOR SUPPRESSING DECREASE IN CHARGE STATE

Abstract

In the present invention, a battery 50 comprises: a positive electrode external terminal 51 and a negative electrode external terminal 52; secondary batteries 62; a management unit 130 that operates by electric power supplied from the secondary batteries 62; a relay 21 provided to a power line 22 that supplies the electric power from the secondary batteries 62 to the management unit 130; and a USB connector 20 to which an external power supply is connected. When the power supply is connected to the USB connector 20, in a case where the relay 21 is turned OFF, the power is supplied from the power supply to the management unit 130, the management unit 130 is activated, and the relay 21 is turned ON.

Description

[Technical field]

[0001] The technology disclosed in this specification relates to a power storage device and a method for suppressing a decrease in a state of charge. [Background technology]

[0002] Patent Document 1 discloses an energy storage device including a management unit that manages an energy storage element such as a lithium ion battery, etc. The management unit that manages the energy storage element operates using power supplied from the energy storage element. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6155781 Summary of the Invention [Problem to be solved by the invention]

[0004] After being shipped from a factory, an energy storage device may be left unused for a long period of time, for example by being stored as inventory in a storehouse. The management unit continues to operate during this time, so the state of charge (SOC) of the energy storage element gradually decreases due to the power consumed by the management unit. For this reason, even if the energy storage element was fully charged when shipped from the factory, the state of charge may be low when the energy storage device is first used.

[0005] For example, in the case of a power storage device mounted on a four-wheeled automobile or motorcycle, the driver may purchase a new power storage device at a dealer (such as an automobile dealer or an automobile parts store) and exchange it for another one. In this case, if the state of charge of the purchased power storage device is low, the driver cannot immediately use the power storage device, which is inconvenient for the driver.

[0006] The present specification discloses an electricity storage device that can suppress a decrease in the state of charge even if the device is left unused for a long period of time after being shipped from the factory, and that can start up a management unit when the use of the electricity storage device is started. [Means for solving the problem]

[0007] An energy storage device according to one embodiment includes a positive external terminal and a negative external terminal, an energy storage element, a management unit that operates using power supplied from the energy storage element, a circuit breaker provided on a power line that supplies power from the energy storage element to the management unit, and a power supply connection terminal to which a power source is connected. When the circuit breaker is turned off and the power source is connected to the power supply connection terminal, power is supplied from the power source to the management unit, causing the management unit to start up and turn on the circuit breaker. The energy storage device according to one embodiment includes a positive external terminal and a negative external terminal, an energy storage element, a management unit that operates using power supplied from the energy storage element, a circuit breaker provided on a power line that supplies power from the energy storage element to the management unit, and a power supply connection terminal, and when the circuit breaker is turned off (open), when an external device is connected to the power supply connection terminal, the management unit is activated and turns on (closes) the circuit breaker. Effect of the Invention

[0008] According to the present technology, it is possible to suppress deterioration of the state of charge even if the power storage device is left unused for a long period of time after being shipped from the factory, and it is possible to start up the management unit when the use of the power storage device is started. [Brief description of the drawings]

[0009] [Figure 1] Motorcycle side view [Diagram 2] Vehicle System Block Diagram [Diagram 3] Exploded perspective view of the battery [Figure 4] Plan view of secondary battery [Diagram 5] Cross-sectional view of line AA in Figure 4 [Figure 6] Battery Block Diagram [Figure 7] Block diagram of a battery according to another embodiment. [Figure 8] Block diagram of a battery according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] (Outline of this embodiment) The energy storage device includes a positive external terminal and a negative external terminal, an energy storage element, a management unit that operates using power supplied from the energy storage element, a circuit breaker provided on a power line that supplies power from the energy storage element to the management unit, and a power supply connection terminal to which a power source is connected.When the circuit breaker is turned off (open), when the power source is connected to the power supply connection terminal, power is supplied from the power source to the management unit, causing the management unit to start up and turn on (close) the circuit breaker. The energy storage device comprises a positive external terminal and a negative external terminal, an energy storage element, a management unit that operates using power supplied from the energy storage element, a circuit breaker provided on a power line that supplies power from the energy storage element to the management unit, and a power supply connection terminal.When the circuit breaker is turned off (open), the management unit is activated when an external device is connected to the power supply connection terminal, and turns on (closes) the circuit breaker.

[0011] One possible method for preventing the deterioration of the state of charge of a storage element that has been left unused for a long period of time is to switch the management unit into a sleep mode to reduce the power consumed by the management unit. However, the sleep mode does not completely cut off the power supply to the management unit, so a certain amount of power continues to be supplied. In the above-described energy storage device, the circuit breaker provided on the power line that supplies power from the energy storage element to the management unit is turned off, completely cutting off the power supply to the management unit. This prevents the management unit from consuming power, and suppresses the deterioration of the state of charge even if the energy storage device is left unused for a long period of time. If the power supply to the management unit is completely cut off, the management unit will stop operating completely, and the storage device cannot be started in this state. According to the storage device described above, when a power source such as an external power source is connected to the power supply connection terminals provided separately from the positive and negative external terminals, power is supplied from the power source to the management unit, so the management unit can be started. When the management unit is started, the circuit breaker is turned on, and thereafter it operates using power supplied from the storage element. In this way, the above-mentioned power storage device can suppress a decrease in the state of charge even if the device is left unused for a long period of time after being shipped from the factory, and the management unit can be started when the user starts using the power storage device. This increases the likelihood that a driver who purchases a power storage device will be able to use the purchased power storage device immediately, improving convenience for the driver.

[0012] The circuit breaker may be factory switched off.

[0013] For example, if the energy storage device is charged to a state of charge of 95% or more when it is shipped from the factory, and the state of charge drops to 90% while it is left unused for an extended period of time, it may be possible to turn off the circuit breaker to prevent the state of charge from dropping any further. However, in this case, the state of charge is allowed to drop to 90%. According to the above-mentioned energy storage device, the circuit breaker is turned off when the device is shipped from the factory, so that the decrease in the state of charge while the device is left unused for a long period of time can be more effectively prevented than in the case where the circuit breaker is turned off when the state of charge falls below a predetermined threshold (e.g., 90%).

[0014] The management unit may turn off the circuit breaker when a state of charge of the energy storage element falls below a predetermined threshold.

[0015] According to the above-described power storage device, it is possible to suppress a decrease in the state of charge even if the power storage device is left unused for a long period of time after being shipped from the factory, and it is possible to start up the management unit when the power storage device is first used.

[0016] The power connection terminal may be a Universal Serial Bus connector (USB connector).

[0017] If the power connection terminal has a special shape, it is necessary to prepare a dedicated external power source that can be connected to that power connection terminal, which requires high costs to realize the function. Because USB is widely used, there are many external power sources and cables available on the market that can be connected to USB connectors (for example, mobile batteries for charging mobile devices such as cell phones and smartphones). For this reason, using a USB connector as the power connection terminal can reduce the cost of starting up the management unit. Another advantage is that there are many external power supplies on the market that can be connected to a USB connector, making them easy to obtain. Since USB is widely used, using a USB connector as the power connection terminal has the advantage that the driver (or dealer staff) can easily understand that they need to connect an external power source or other power source to the USB connector.

[0018] The management unit may record a log relating to the energy storage element, and transmit the log to an external device via the universal serial bus connector.

[0019] According to the power storage device, the USB connector can be used not only for connecting a power source for starting up the management unit, but also as a communication interface for transmitting logs to an external device.

[0020] Control software of the management unit may be updatable via the universal serial bus connector.

[0021] Updating the control software of the management unit after the power storage device is shipped from the factory has not been considered in the past. For this reason, conventional power storage devices do not have an interface for updating the control software. According to the above-mentioned power storage device, the control software of the management unit can be updated via a universal serial bus connector, so that the functions of the power storage device can be improved even after the power storage device is shipped from the factory.

[0022] The power supply may further include a charging unit that charges the power storage element with power supplied from an external power source connected to the universal serial bus connector.

[0023] For example, a power storage device used to start a vehicle engine is charged by an alternator when the engine is running. However, if the vehicle is parked for a long period of time, the charge state of the power storage element may decrease, making it impossible to start the engine. In this case, the above-mentioned power storage device allows the power storage element to be charged by connecting an external power source to the USB connector. As described above, since many external power sources that can be connected to a USB connector are commercially available, there is no need to prepare a dedicated charger for charging the power storage element. This has the advantage of improving convenience when charging the power storage element.

[0024] The invention disclosed in this specification can be realized in various forms, such as an apparatus, a method, a computer program for implementing the functions of these apparatus or methods, and a recording medium on which the computer program is recorded.

[0025] <Embodiment 1> The first embodiment will be described with reference to FIGS. As shown in FIG. 1, a battery 50 (an example of a power storage device) according to the first embodiment is a battery for a motorcycle mounted on a motorcycle 10.

[0026] 2, a starter 10A, an alternator 10B, and accessories 10C (headlight, air conditioner, audio, etc.) mounted on the motorcycle 10 are connected to the battery 50. The battery 50 is an engine starting battery that supplies power to the starter 10A to start the engine. The battery 50 is charged by the alternator 10B while the engine is running.

[0027] When the engine of the motorcycle 10 is running, power is supplied from the alternator 10B to the accessories 10C. Therefore, the battery 50 does not supply power to the accessories 10C while the engine is running, but supplies power to the accessories 10C when the accessories 10C are used while the engine is stopped. Generally, a battery 50 for a motorcycle does not have a function for communicating with the ECU of the motorcycle 10. The battery 50 for a motorcycle according to the first embodiment also does not have a function for communicating with the ECU.

[0028] (1) Battery configuration As shown in FIG. 3, the battery 50 includes a battery pack 60, a circuit board unit 65, and a container 71. The container 71 includes a main body 73 and a lid 74 made of a synthetic resin material. The main body 73 is cylindrical with a bottom. The main body 73 includes a bottom portion 75 and four side portions 76. An upper opening 77 is formed at the upper end portion by the four side portions 76.

[0029] The container 71 houses the battery pack 60 and the circuit board unit 65. The battery pack 60 has twelve secondary batteries 62 (an example of an energy storage element). The secondary batteries 62 are, for example, lithium ion batteries. The twelve secondary batteries 62 are connected in three parallel and four in series. The circuit board unit 65 includes a circuit board 100 and electronic components mounted on the circuit board 100, and is disposed above the battery pack 60.

[0030] The lid body 74 closes an upper opening 77 of the main body 73. An outer peripheral wall 78 is provided around the lid body 74. The lid body 74 has a protruding portion 79 that is generally T-shaped in plan view. A positive external terminal 51 is fixed to one corner of the front portion of the lid body 74, and a negative external terminal 52 is fixed to the other corner. When the battery 50 is mounted on a vehicle, the positive external terminal 51 and the negative external terminal 52 are electrically connected to a load (e.g., auxiliary machinery 10C). The battery 50 discharges and charges through the positive external terminal 51 and the negative external terminal 52.

[0031] 4 and 5, the secondary battery 62 contains an electrode assembly 83 together with a non-aqueous electrolyte in a rectangular parallelepiped case 82. The case 82 has a case body 84 and a lid 85 that closes the upper opening. Although not shown in detail, the electrode body 83 is configured by disposing a separator made of a porous resin film between a negative electrode element made of a copper foil substrate coated with an active material and a positive electrode element made of an aluminum foil substrate coated with an active material. Both of these are strip-shaped, and are wound flatly so that they can be housed in the case body 84, with the negative electrode element and the positive electrode element offset from each other on opposite sides in the width direction relative to the separator.

[0032] A positive terminal 87 is connected to the positive element via a positive current collector 86, and a negative terminal 89 is connected to the negative element via a negative current collector 88. The positive current collector 86 and the negative current collector 88 each include a flat base 90 and a leg 91 extending from the base 90. A through hole is formed in the base 90. The leg 91 is connected to the positive element or the negative element. The positive terminal 87 and the negative terminal 89 each include a terminal body 92 and a shaft 93 protruding downward from the center of the lower surface of the terminal body 92. Of these, the terminal body 92 and the shaft 93 of the positive terminal 87 are integrally formed from aluminum (a single material). In the negative terminal 89, the terminal body 92 is made of aluminum, and the shaft 93 is made of copper, and these are assembled together. The terminal main bodies 92 of the positive electrode terminal 87 and the negative electrode terminal 89 are disposed on both ends of the lid 85 via gaskets 94 made of an insulating material, and are exposed to the outside from the gaskets 94 .

[0033] The lid 85 has a pressure relief valve 95. As shown in Fig. 2, the pressure relief valve 95 is located between the positive electrode terminal 87 and the negative electrode terminal 89. The pressure relief valve 95 opens to reduce the internal pressure of the case 82 when the internal pressure of the case 82 exceeds a limit value. The secondary battery 62 is not limited to a cell (prismatic cell) having a rectangular parallelepiped case 82. The secondary battery may be a pouch cell or a cylindrical cell.

[0034] (2) Battery electrical configuration As shown in FIG. 6, the battery 50 includes a battery pack 60 and a BMU 101 (Battery Management Unit) that manages the battery pack 60.

[0035] The battery pack 60 is composed of multiple secondary batteries (cells) 62. In this embodiment, there are 12 secondary batteries 62, which are connected in series and three in parallel. In Fig. 6, three secondary batteries 62 connected in parallel are represented by one battery symbol. The battery 50 is rated at 12V. The power line 70P is a power line that connects the positive external terminal 51 and the positive electrode of the battery pack 60. The power line 70N is a power line that connects the negative external terminal 52 and the negative electrode of the battery pack 60. The negative electrode of the battery pack 60 is connected to a signal ground G1. The battery pack 60 has the signal ground G1 as its reference potential. The negative external terminal 52 is connected to a body ground G2. The body ground G2 is the body of the motorcycle 10. The body ground G2 is the reference potential of the motorcycle 10.

[0036] The BMU 101 includes a current sensor 53, a voltage sensor 110, a FET 55, a management unit 130, a relay 21 (an example of a circuit breaker), and a USB connector 20 (an example of a power connection terminal). The battery pack 60, the current sensor 53, and the FET 55 are connected in series via power lines 70P and 70N. The FET 55, the current sensor 53, and the management unit 130 are mounted on a circuit board 100, and a signal ground G1 of the circuit board 100 is used as a reference potential (operation reference).

[0037] The current sensor 53 is located at the negative electrode of the battery pack 60, and is provided on the negative-electrode power line 70N. The current sensor 53 measures the current I of the battery pack 60, and outputs the measured current I to the management unit 130. The voltage sensor 110 detects the voltage V of each secondary battery 62 and the total voltage of the battery pack 60, and outputs the results to the management unit 130. The total voltage of the battery pack 60 is the sum of the voltages of the four secondary batteries 62. The temperature sensor 111 is provided in one or two of the secondary batteries 62 , and detects the temperature of the secondary batteries 62 and outputs the temperature to the management unit 130 .

[0038] The FET 55 is located at the negative electrode of the battery pack 60, and is provided on the negative power line 70N. The FET 55 has a charging FET 55A and a discharging FET 55B. The charging FET 55A and the discharging FET 55B are semiconductor switches for power, and more specifically, are N-channel field effect transistors (FETs). The sources S of the charging FET 55A and the discharging FET 55B are reference terminals. The gates G of the charging FET 55A and the discharging FET 55B are control terminals. The drains D of the charging FET 55A and the discharging FET 55B are connection terminals.

[0039] The source S of the charging FET 55A is connected to the negative electrode of the battery pack 60. The source S of the discharging FET 55B is connected to the negative external terminal 52. The charging FET 55A and the discharging FET 55B are connected back-to-back by connecting their drains D to each other. The charging FET 55A has a parasitic diode 56A. The forward direction of the parasitic diode 56A is the same as the discharging direction. The discharging FET 55B has a parasitic diode 56B. The forward direction of the parasitic diode 56B is the same as the charging direction.

[0040] The discharge FET 55B has a source S connected to the negative external terminal 52, and therefore the body ground G2 is its reference potential. The charge FET 55A has a source S connected to the negative electrode of the battery pack 60. The negative electrode of the battery pack 60 is connected to the signal ground G1 of the circuit board 100, and therefore the signal ground G1 is its reference potential. The charging FET 55A is turned on when an H-level voltage is applied to the gate G, and is turned off when an L-level voltage is applied to the gate G. The same is true for the discharging FET 55B.

[0041] The management unit 130 operates using power supplied from the battery pack 60, and is connected to the power line 70P via the power line 22. The management unit 130 includes a CPU 131, a ROM 132, and a RAM 133. The ROM 132 stores control software, various control data, and the like. The management unit 130 manages the battery 50 by executing the control software stored in the ROM 132. The ROM 132 according to this embodiment is assumed to be rewritable.

[0042] Under normal conditions, the management unit 130 applies an H-level voltage to the gate G of the charging FET 55A and the gate G of the discharging FET 55B to turn on the charging FET 55A and the discharging FET 55B. When both the charging FET 55A and the discharging FET 55B are on, the battery pack 60 is capable of both charging and discharging.

[0043] The relay 21 is provided on a power line 22 (an example of a power line) that supplies power from the battery pack 60 to the management unit 130. The relay 21 is turned on and off by the management unit 130. The battery 50 is shipped from the factory with the relay 21 in the off state. The USB connector 20 is a connector conforming to the USB (Universal Serial Bus) standard. The USB connector 20 is connected to the management unit 130. When an external power source is connected to the USB connector 20, power is supplied from the external power source to the management unit 130. The management unit 130 can also communicate with an external device via the USB connector 20. The USB connector 20 may be a USB port provided in the housing 71. If the USB connector 20 is provided on the lid 74 of the housing 71, the wiring can be simplified.

[0044] (3) Processing performed by the Management Department The relay-on process, the SOC estimation process, the log recording process, and the log transmission process executed by the management unit 130 at the start of use will be described.

[0045] (3-1) Relay ON process when starting use As described above, the battery 50 is shipped from the factory with the relay 21 in the off state. The relay on process at the start of use is a process for turning on the relay 21 when the use of the battery 50 is started. For example, when a rider of motorcycle 10 requests a dealer to replace battery 50, a staff member at the dealer connects an external power supply to USB connector 20 before (or after) installing battery 50 on motorcycle 10. When the external power supply is connected to USB connector 20, power is supplied from the external power supply to management unit 130, and management unit 130 starts up. When management unit 130 starts up, it turns on relay 21. Thereafter, management unit 130 operates using the power supplied from battery 50.

[0046] (3-2) SOC estimation process The SOC estimation process is a process for estimating the state of charge of the secondary battery 62 by a current integration method. The current integration method is a method for estimating the state of charge (SOC) by measuring the amount of power flowing in and out of the secondary battery 62 by measuring the charge / discharge current of the secondary battery 62 at a predetermined time interval with the current sensor 53, and adding or subtracting this from the initial capacity.

[0047] While the current integration method has the advantage that the SOC can be estimated even while the secondary battery 62 is in use, the current is constantly measured and the amount of charge / discharge power is integrated, so that measurement errors of the current sensor 53 accumulate and may gradually become inaccurate. For this reason, the management unit 130 may reset the SOC estimated by the current integration method based on the open circuit voltage (OCV) of the secondary battery 62. Specifically, since there is a relatively accurate correlation between the OCV and the SOC, the SOC may be estimated from the OCV, and the SOC estimated by the current integration method may be reset by the SOC estimated from the OCV.

[0048] The OCV is not limited to the voltage when the circuit is open, but may be, for example, the voltage when the current value flowing through the secondary battery 62 is less than a small reference value.

[0049] (3-3) Logging process The log recording process is a process for storing a log related to the battery 50 in the ROM 132. The log related to the battery 50 includes the current value, voltage value, temperature, SOC, etc. of the secondary battery 62. The log related to the battery 50 is not limited to these, and can be appropriately selected.

[0050] (3-4) Log sending process The log transmission process is a process of transmitting the log stored in ROM 132 to an external device (such as a personal computer or a smartphone) after use of battery 50 has started. Specifically, an operator connects the external device to USB connector 20 and operates the external device to instruct it to receive the log. When instructed to receive the log, the external device requests management unit 130 to transmit the log via USB connector 20. When requested to transmit the log, management unit 130 transmits the log stored in ROM 132 to the external device.

[0051] (4) Effects of the embodiment According to the battery 50, the relay 21 provided on the power line 22 that supplies power from the secondary battery 62 to the management unit 130 is turned off, completely cutting off the power supply to the management unit 130. As a result, power is no longer consumed by the management unit 130, and a decrease in the SOC is suppressed even if the battery 50 is left unused for a long period of time. However, if the power supply to management unit 130 is completely cut off, management unit 130 will stop operating completely, and therefore it is not possible to start using battery 50 in this state. According to battery 50, when an external power source is connected to USB connector 20, power is supplied from the external power source to management unit 130, so management unit 130 can be started. When management unit 130 is started, it turns on relay 21, and thereafter operates using power supplied from secondary battery 62. In this way, according to the battery 50, even if the battery is left unused for a long period of time after being shipped from the factory, the decrease in SOC can be suppressed, and the management unit 130 can be started when starting to use the battery 50. Therefore, a driver who purchases the battery 50 is more likely to be able to immediately use the purchased battery 50, improving convenience for the driver.

[0052] According to the battery 50, the relay 21 is turned off when the battery is shipped from the factory, so that the deterioration of the state of charge during long periods of storage can be more effectively prevented than in the case where the relay 21 is turned off when the SOC falls below a predetermined threshold.

[0053] According to the battery 50, the power connection terminal is the USB connector 20. External power sources (such as mobile batteries for charging portable terminals such as mobile phones and smartphones) that can be connected to the USB connector 20 are widely available on the market and are generally inexpensive. For this reason, using the USB connector 20 as the power connection terminal can reduce the cost of starting up the management unit 130. Another advantage is that there are many commercially available external power sources that can be connected to the USB connector 20, making them easily available. Because USB is widely used, using the USB connector 20 as a power connection terminal also has the advantage that store staff and others can easily understand that they need to connect an external power source to the USB connector 20.

[0054] With the battery 50, the USB connector 20 can be used not only for connecting an external power source for starting the management unit 130, but also as a communication interface for transmitting logs to an external device. According to the battery 50, since the log can be transmitted by connecting an external device to the USB connector 20, it is not necessary to disassemble the battery 50 in order to obtain the log. Therefore, there is an advantage that the log can be obtained more easily than in the case where the battery 50 is disassembled.

[0055] <Other embodiments> The technology disclosed in this specification is not limited to the embodiments described above and in the drawings, and for example, the following embodiments are also included in the technical scope disclosed in this specification.

[0056] (1) In the above embodiment, the USB connector 20 is used as an example of the power supply connection terminal, but the power supply connection terminal is not limited to this. For example, the power supply connection terminal may be a connector of another standard, or may be a connector designed specifically for the battery 50.

[0057] (2) In the above embodiment, the relay 21 is used as a circuit breaker. However, the circuit breaker may be a field effect transistor (FET).

[0058] (3) In the above embodiment, the relay 21 is turned off at the time of shipment from the factory, but the relay 21 may be turned on at the time of shipment from the factory. For example, the battery 50 is charged to an SOC of 95% or more at the time of shipment from the factory, and when the SOC drops to a predetermined threshold value (e.g., 90%) or less while the battery 50 is left unused for a long period of time, the relay 21 may be turned off. In this way, the decrease in SOC can be suppressed even if the battery 50 is left unused for a long period of time after shipment from the factory, and the management unit can be started when the use of the battery 50 is started.

[0059] (4) In the above embodiment, the battery 50 has been described as a battery for starting the engine of the motorcycle 10, but the use of the battery 50 is not limited to this. For example, the battery 50 may be a battery for starting the engine of a four-wheeled vehicle, or an auxiliary battery mounted on an electric vehicle, a plug-in hybrid vehicle, or an electric motorcycle to supply power to auxiliary devices. The battery 50 may be a battery used in an uninterruptible power supply (UPS).

[0060] (5) The battery 50 may be capable of updating the control software of the management unit 130 via the USB connector 20. Specifically, for example, an external computer may be connected to the USB connector 20, and the control software stored in the ROM 132 may be rewritten from the external computer. In this way, the function of the battery 50 can be improved even after it has been shipped from the factory. That is, with the battery 50, the USB connector 20 can be used not only for connecting an external power source for starting up the management unit 130, but also as a communication interface for updating the control software.

[0061] (6) As shown in Fig. 7, the battery 50 may include a charging unit 134 that charges the assembled battery 60 with power supplied from an external power source connected to the USB connector 20. As shown in Fig. 7, the charging unit 134 is connected in parallel with the assembled battery 60. When the external power source is connected to the USB connector 20, the charging unit 134 boosts the voltage applied from the external power source (e.g., from 5 V to 13 V) to charge the assembled battery 60. 7, the battery pack 60 can be charged by connecting an external power source to the USB connector 20. That is, according to the battery 50, the USB connector 20 can be used not only to connect an external power source for starting up the management unit 130, but also to charge the battery pack 60. Since many external power sources that can be connected to the USB connector 20 are commercially available, there is no need to prepare a dedicated charger for charging the battery pack 60. This has the advantage of improving convenience when charging the battery pack 60. (7) As shown in Fig. 8, the battery 50 may include two USB connectors 20. For example, two USB ports may be provided in the housing 71. One end and the other end of a single USB cable (not shown) may be connected to the two USB connectors 20. This battery 50 includes a positive external terminal 51 and a negative external terminal 52, a secondary battery 62, a management unit 130 that operates with power supplied from the secondary battery 62, a circuit breaker 21 provided on a power line 22 that supplies power from the secondary battery 62 to the management unit 130, and power supply connection terminals 20, 20. When the circuit breaker 21 is turned off (open), when one power supply connection terminal 20 is connected to the other power supply connection terminal 20 and the secondary battery 62 (power supply) via a cable, power is supplied from the secondary battery 62 to the management unit 130, the management unit 130 is started, and the circuit breaker 21 is turned on (closed). With this configuration, no external power supply is required to start the management unit 130.

[0062] (8) The battery 50 may include a positive external terminal 51 and a negative external terminal 52, a secondary battery 62, a management unit 130 that operates with power supplied from the secondary battery 62, a circuit breaker 21 provided on a power line 22 that supplies power from the secondary battery 62 to the management unit 130, and a USB connector (USB port) 20 provided in a container 71. When the circuit breaker 21 is turned off (open), the management unit 130 may be activated when an external device is connected via the USB connector 20, and the circuit breaker 21 may be turned on (closed). A configuration in which a power supply connection terminal (USB connector) is provided in a housing 71 for a battery 50 rated at 12 V, in addition to the positive external terminal 51 and the negative external terminal 52, has not existed in the past and is therefore novel. The battery 50 may be rated at 24 V or 48 V. (9) In the above embodiment, the secondary battery 62 is used as an example of the power storage element, but the power storage element is not limited to this. For example, the power storage element may be a capacitor that involves an electrochemical reaction. [Explanation of symbols]

[0063] 20 USB connector (example of power connection terminal) 21 Relay (an example of a circuit breaker) 22 Power line (an example of a power line) 50 Battery (an example of an energy storage device) 62 Secondary battery (an example of a storage element) 130 Management Department 134 Live parts

Claims

1. An in-vehicle power storage device, A positive electrode external terminal and a negative electrode external terminal, an electric storage element that supplies electric power to a starter or auxiliary machinery via the positive electrode external terminal and the negative electrode external terminal after the electric storage device is mounted on a vehicle; A management unit that operates using power supplied from the power storage element; a breaker provided on a power line that supplies power from the storage element to the management unit; a power supply connection terminal to which a power supply is connected; a container provided with the power supply connection terminal, the positive electrode external terminal, and the negative electrode external terminal, and configured to house the energy storage element; Equipped with When the breaker is turned off before or after the storage device is mounted on the vehicle, when the power source is connected to the power source connection terminal, power is supplied from the power source to the management unit, the management unit is started, and the breaker is turned on; The power supply connection terminal is a universal serial bus connector, and the power storage element is not charged even when a power supply is connected to the universal serial bus connector.

2. An in-vehicle power storage device, A positive electrode external terminal and a negative electrode external terminal, an electric storage element that supplies electric power to a starter or auxiliary machinery via the positive electrode external terminal and the negative electrode external terminal after the electric storage device is mounted on a vehicle; A management unit that operates using power supplied from the power storage element; a breaker provided on a power line that supplies power from the storage element to the management unit; A power connection terminal; a container provided with the power supply connection terminal, the positive electrode external terminal, and the negative electrode external terminal, and configured to house the energy storage element; Equipped with When the breaker is turned off before or after the storage device is mounted on the vehicle, when an external device is connected to the power supply connection terminal, the management unit is started and turns on the breaker, The power supply connection terminal is a universal serial bus connector, and the power storage element is not charged even when a power supply is connected to the universal serial bus connector.

3. The power storage device according to claim 1 or 2, The power storage device, wherein the circuit breaker is turned off when shipped from a factory.

4. The power storage device according to any one of claims 1 to 3, The management unit turns off the circuit breaker when the state of charge of the storage element falls below a predetermined threshold.

5. A power storage device according to any one of claims 1 to 4, The management unit records a log relating to the power storage element and transmits the log to an external device via the universal serial bus connector.

6. A power storage device according to any one of claims 1 to 5, The power storage device, wherein control software of the management unit is updatable via the universal serial bus connector.

7. A method for suppressing a decrease in a state of charge of an on-board power storage device comprising: a positive external terminal and a negative external terminal; a power storage element that supplies power to a starter or auxiliary machinery via the positive external terminal and the negative external terminal; a management unit that operates by power supplied from the power storage element; a power source connection terminal; and a housing that is provided with the power source connection terminal, the positive external terminal, and the negative external terminal and that houses the power storage element, a power supply connection terminal that is a universal serial bus connector, and a power supply connection terminal that is a power supply connection terminal that is a universal serial bus connector, and a power supply connection terminal that is a power supply connection terminal that is a power supply connection terminal that is a power supply connection terminal that is a power supply connection terminal that is a power supply connection terminal, and a power supply connection terminal that is a power supply connection terminal that is a power supply connection terminal, and a power supply connection terminal that is a power supply connection terminal, and a power supply connection terminal that is a power supply connection terminal, and a power supply connection terminal that is a power supply connection terminal, and a power supply connection terminal that is a power supply connection terminal, and a power supply connection terminal that is a power supply connection terminal, and a power supply connection terminal that is a power supply connection terminal, and a power supply connection terminal that is a power supply connection terminal, and a power supply connection terminal that is a universal serial bus connector ....

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