Power storage system and power storage device

Abstract

To facilitate carrying of a power storage device 10.SOLUTION: The power storage system 1 includes a power storage device 10 and a charger 20 that are attachable to and detachable from a vehicle. The power storage device 10 includes a battery cell 151, a power terminal 141,2, a memory 120 that stores information of the battery cell 151, and signal terminals 143 to 106 that transmit and receive a voltage signal and a temperature signal of the battery cell 151 and input / output data of the memory 120. The charging device 20 includes signal terminals 243 to 6 that transmit and receive a voltage signal, a temperature signal, and input-output data, a power output-terminal 2412 to the power storage device 10, AC power input-terminals 261 to 3, a DC power input-terminal 2512, a power conversion unit 250 that converts input-power into output-power, a current conversion unit 234, a voltage conversion unit 232, and a temperature conversion unit 233 that convert a current signal, a voltage signal, and a temperature signal of the battery cell 151 into a current datum, a voltage datum, and a temperature datum, respectively, and a ECU210 that processes the current datum, the voltage datum, and the temperature datum.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a power storage system and a power storage device, and particularly to a power storage system including a power storage device detachable from a vehicle and a charger connectable to the power storage device, and a power storage device detachable from a vehicle. [Background technology]

[0002] Conventionally, there has been an in-vehicle power storage system that can control charging of a vehicle's storage battery so as to reduce power consumption, even when using a storage battery module that is detachable from the vehicle (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-57998 Summary of the Invention [Problem to be solved by the invention]

[0004] The in-vehicle power storage system of Patent Document 1 is configured to include a storage battery controller in addition to a storage battery module. The storage battery for driving power installed in a vehicle is large and has a large capacity compared to storage batteries used for other electrical devices. Therefore, the storage battery module is heavy and large, making it difficult to transport.

[0005] Fig. 6 is a diagram showing an outline of the configuration of a conventional power storage system 9. Referring to Fig. 6, the power storage system 9 includes a power storage device 80 that is detachable from a vehicle, and a charger 90 that is connectable to the power storage device 80. The power storage device 80 includes an electronic control unit (ECU) 810, a battery 850, a switch 830, a switch drive unit 831, a voltage conversion unit 832, a temperature conversion unit 833, a current conversion unit 834, a current sensor 835, power terminals 841 and 842, and a signal terminal 843. The ECU 810 includes a CPU (Central Processing Unit) 811, a memory 812, and a communication unit 813. The battery 850 includes a plurality of battery cells 851, a voltage sensor 852, and a temperature sensor 853.

[0006] The battery cells 851 are, for example, lithium-ion batteries. The battery cells 851 may also be nickel-metal hydride batteries or all-solid-state batteries. The battery cells 851 included in the battery 850 are connected in series. The voltage sensor 852 detects the voltage of each battery cell 851 and outputs a voltage signal indicating the detected voltage to the voltage conversion unit 832. The voltage conversion unit 832 converts the analog voltage signal from the voltage sensor 852 into digital voltage data and outputs the converted voltage data to the ECU 810. The temperature sensor 853 detects the temperature of each battery cell 851 and outputs a temperature signal indicating the detected temperature to the temperature conversion unit 833. The temperature conversion unit 833 converts the analog temperature signal from the temperature sensor 853 into digital temperature data and outputs the converted temperature data to the ECU 810. Current sensor 835 is provided in the wire between battery 850 and power terminal 842, detects the current flowing through this wire, and outputs a current signal indicating the detected current to current converter 834. Current converter 834 converts the analog current signal from current sensor 835 into digital current data and outputs the converted current data to ECU 810. Switch driver 831 controls the connection and disconnection of switch 830 in accordance with a control signal from ECU 810. Switch 830 is provided in the wire between battery 850 and power terminal 841, and is driven by switch driver 831 to establish a connection state in which current flows between battery 850 and power terminal 841, or to establish a disconnection state in which current does not flow between battery 850 and power terminal 841.

[0007] The charger 90 includes an ECU 910, a power conversion unit 950, power output terminals 941 and 942, DC power input terminals 951 and 952, AC power input terminals 961 to 963, and a signal terminal 943. The ECU 910 includes a CPU 911, a memory 912, and a communication unit 913. The DC power input terminals 951 and 952 receive DC power input from output terminals 31 and 32 of the DC power supply 30 or output terminals 71 and 72 of the solar panel 70, and output the received DC power to the power conversion unit 950. The AC power input terminals 961 to 963 receive AC power input from output terminals 51 to 53 of the AC power supply 50, and output the received AC power to the power conversion unit 950. Power conversion unit 950 is controlled by ECU 910 to convert input DC power or AC power into DC power of the charging voltage of battery 850 and output it to power output terminals 941 and 942 .

[0008] Power output terminals 941, 942 and a signal terminal 943 of the charger 90 are connected to power terminals 841, 842 and a signal terminal 843 of the power storage device 80, respectively. Power from the power conversion unit 950 is supplied to the battery 850 via the power output terminals 941, 942 and the power terminals 841, 842. The supplied power charges the battery cells 851 of the battery 850. A communication unit 913 of the ECU 910 of the charger 90 and a communication unit 813 of the ECU 810 of the power storage device 80 communicate with each other via the signal terminals 943, 843. A CPU 911 of the ECU 910 of the charger 90 processes data stored in the memory 912 or received from the communication unit 913 in accordance with a program stored in the memory 912, and controls the charger 90 by storing the processed data in the memory 912 or outputting the processed data from the communication unit 913. The CPU 811 of the ECU 810 of the power storage device 80 processes data stored in the memory 812 or received from the communication unit 813 in accordance with a program stored in the memory 812, and controls the power storage device 80 by storing the processed data in the memory 812 or outputting the processed data from the communication unit 813.

[0009] As described above, in conventional power storage system 9, components other than battery 850, such as ECU 810, voltage conversion unit 832, switch drive unit 831, voltage conversion unit 832, temperature conversion unit 833, and current conversion unit 834, are provided on the side of power storage device 80. For this reason, when power storage system 9 is mounted on a vehicle, if power storage device 80 is configured to be detachable from the vehicle, the volume and weight of the components other than battery 850 are included in power storage device 80, making power storage device 80 large and heavy and making it difficult to transport.

[0010] Furthermore, in order to make it easier to attach and detach power storage device 80 to and from the vehicle, it is conceivable to mount a plurality of power storage devices 80 on the vehicle and reduce the amount of stored electricity per power storage device 80, thereby reducing the volume and weight of power storage device 80. In this way, the ratio of the volume and weight of the parts other than battery 850 to the volume and weight of the plurality of power storage devices 80 mounted on the vehicle becomes even greater.

[0011] This disclosure has been made to solve the above-mentioned problems, and its purpose is to provide a power storage system and a power storage device that is easy to carry. [Means for solving the problem]

[0012] The power storage system according to this disclosure includes a power storage device detachable from a vehicle and a charger connectable to the power storage device. The power storage device includes at least one battery cell, a first power terminal for inputting and outputting power from the battery cell, a memory for storing information about the battery cell, and a first signal terminal for transmitting and receiving an analog voltage signal indicating the voltage of the battery cell, an analog temperature signal indicating the temperature of the battery cell, and input / output data from and to the charger. The charger includes a second signal terminal for transmitting and receiving the voltage signal, the temperature signal, and the input / output data to and from the power storage device, a second power terminal for outputting power to the power storage device, a third power terminal for inputting power from a power source, a power converter for converting the power input from the third power terminal into power output from the second power terminal, a current converter for converting an analog current signal indicating the current flowing through the battery cell into digital current data, a voltage converter for converting a voltage signal into digital voltage data, a temperature converter for converting a temperature signal into digital temperature data, and an electronic control unit for processing the current data, voltage data, and temperature data.

[0013] According to this configuration, the charger includes an electronic control unit for controlling the power storage device. This makes the power storage device lighter and smaller than when the power storage device includes an electronic control unit. As a result, it is possible to provide a power storage system in which the power storage device is easy to carry.

[0014] The charger may be configured to be connectable to a plurality of power storage devices. With this configuration, the ratio of the volume and weight of the parts other than the battery cells to the combined volume and weight of the plurality of power storage devices can be made even lighter and smaller than when each of the plurality of power storage devices includes an electronic control unit.

[0015] The electronic control unit may control the power conversion unit to charge the power storage device using the information about the battery cells indicated by the input / output data. With this configuration, even if the electronic control unit that controls the power storage device is provided in a charger, it is possible to appropriately control charging of the power storage device using the information about each battery cell of the power storage device.

[0016] According to another aspect of the present disclosure, a power storage device is detachable from a vehicle and includes at least one battery cell, a power terminal for inputting and outputting power from the battery cell, a memory for storing information about the battery cell, an analog voltage signal indicating the voltage of the battery cell, an analog temperature signal indicating the temperature of the battery cell, and a signal terminal for transmitting and receiving input and output data of the memory to and from a charger. With this configuration, it is possible to provide a power storage device that is easy to carry. [Effects of the Invention]

[0017] According to this disclosure, it is possible to provide a power storage system and a power storage device that is easy to carry. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a diagram showing an outline of the configuration of a power storage system according to a first embodiment; [Figure 2] FIG. 6 is a diagram showing an outline of the configuration of a power storage system according to a second embodiment. [Figure 3] FIG. 10 is a diagram illustrating an outline of the configuration of a power storage system according to a third embodiment. [Figure 4] FIG. 10 is a diagram showing an outline of the configuration of a power storage system according to a fourth embodiment. [Figure 5] FIG. 10 is a diagram showing an outline of the configuration of a power storage system according to a fifth embodiment. [Figure 6] FIG. 1 is a diagram illustrating a schematic configuration of a conventional power storage system. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0020] [First embodiment] Fig. 1 is a diagram showing an outline of the configuration of a power storage system 1 of the first embodiment. Referring to Fig. 1, the power storage system 1 includes a power storage device 10 that is detachable from a vehicle, and a charger 20 that is connectable to the power storage device 10. The charger 20 includes an ECU 210, a power conversion unit 250, a switch drive unit 231, a voltage conversion unit 232, a temperature conversion unit 233, a current conversion unit 234, a current sensor 235, power output terminals 241 and 242, DC power input terminals 251 and 252, AC power input terminals 261 to 263, and signal terminals 243 to 246. The ECU 210 includes a CPU 211, a memory 212, and a communication unit 213.

[0021] The power storage device 10 includes a battery 150, a switch 130, a memory 120, power terminals 141 and 142, and signal terminals 143 to 146. The battery 150 includes a plurality of battery cells 151, a voltage sensor 152, and a temperature sensor 153. The battery cells 151 are, for example, lithium ion batteries. The battery cells 151 may also be nickel-metal hydride batteries or all-solid-state batteries. The battery cells 151 included in the battery 150 are connected in series.

[0022] Power output terminals 241, 242 and signal terminals 243 to 246 of charger 20 are respectively connected to power terminals 141, 142 and signal terminals 143 to 146 of power storage device 10. In this embodiment, one power output terminal 241, power terminal 141, and DC power input terminal 251 are positive terminals, and the other power output terminal 242, power terminal 142, and DC power input terminal 252 are negative terminals, but the positive and negative terminals may be reversed.

[0023] DC power input terminals 251, 252 receive DC power input from output terminals 31, 32 of DC power supply 30 or output terminals 71, 72 of solar panel 70, and output the received DC power to power conversion unit 250. AC power input terminals 261-263 receive AC power input from output terminals 51-53 of AC power supply 50, and output the received AC power to power conversion unit 250. AC power input terminals 261-263 are terminals for U-phase, V-phase, and W-phase of three-phase AC, respectively. Output terminals 51-53 are terminals for U-phase, V-phase, and W-phase of three-phase AC, respectively. Note that single-phase AC may be used instead of three-phase AC. Power conversion unit 250 is controlled by ECU 210, converts the input DC power or AC power into DC power of a charging voltage for battery 150, and outputs the converted power to power output terminals 241, 242. The power from the power conversion unit 250 is supplied to the battery 150 via the power output terminals 241 and 242 and the power terminals 141 and 142. The battery cells 151 of the battery 150 are charged by the supplied power.

[0024] The voltage sensor 152 detects the voltage of each battery cell 151 and outputs a voltage signal indicating the detected voltage to the voltage conversion unit 232 via signal terminals 144 and 244. The voltage conversion unit 232 converts the analog voltage signal from the voltage sensor 152 into digital voltage data and outputs the converted voltage data to the ECU 210. The temperature sensor 153 detects the temperature of each battery cell 151 and outputs a temperature signal indicating the detected temperature to the temperature conversion unit 233 via signal terminals 145 and 245. The temperature conversion unit 233 converts the analog temperature signal from the temperature sensor 153 into digital temperature data and outputs the converted temperature data to the ECU 210. The current sensor 235 is provided in the electric wire between the power output terminal 242 and the power conversion unit 250, detects the current flowing through this electric wire, and outputs a current signal indicating the detected current to the current conversion unit 234. Current conversion unit 234 converts the analog current signal from current sensor 235 into digital current data and outputs the converted current data to ECU 210. Switch drive unit 231 controls the connection and disconnection of switch 130 in accordance with a control signal from ECU 210. Switch 130 is provided on an electric wire between battery 150 and power terminal 141. Driven by switch drive unit 231, switch 130 is brought into a connection state in which current flows between battery 150 and power terminal 141, or into a disconnection state in which current does not flow between battery 150 and power terminal 141.

[0025] Communication unit 213 of ECU 210 of charger 20 and memory 120 of power storage device 10 communicate with each other via signal terminals 246, 146. CPU 211 of ECU 210 of charger 20 processes data stored in memory 212, received from communication unit 913, and received from memory 120 in accordance with a program stored in memory 212, and controls charger 20 and power storage device 10 by storing the processed data in memory 912, outputting the processed data from communication unit 913, and transmitting the processed data to memory 120.

[0026] The memory 120 may store the OCV (Open Circuit Voltage) of each battery cell 151 before charging or discharging, and may also record, for each battery cell 151, ΔV, which is the difference between the OCV and CCV (Closed Circuit Voltage) during current flow. The memory 120 may also store the measured internal resistance of each battery cell 151. The memory 120 may also store the number of charges, the number of full charges, the full charge capacity of each battery cell 151, the amount of drop in internal resistance of each battery cell 151, or a history of past abnormality detection. This allows the ECU 210 of the charger 20 to detect potential abnormalities in the battery cells 151 and appropriately control charging, using the data stored in the memory 120.

[0027] The CPU 211 of the ECU 210 may integrate the charging current using the current from the current conversion unit 234, or may integrate the charging power using the voltage from the current and voltage conversion unit 232. The CPU 211 of the ECU 210 may successively estimate the amount of charge stored in each battery cell 151 from the integrated value of the current flowing through the battery cell 151 and the range of change in OCV, and successively store the estimated amount of charge in the memory 120. This makes it possible to estimate the current SOC (State Of Charge) of the battery 150.

[0028] The CPU 211 of the ECU 210 of the charger 20 may measure and record the OCV of each battery cell 151 before starting charging of the power storage device 10, and determine the full charge capacity of each battery cell 151 and the variation in full charge capacity from the change in the amount of charging energy from the start of charging until charging is stopped and the OCV at the time charging is stopped, and store the determined values ​​in the memory 120 of the power storage device 10.

[0029] Furthermore, the memory 120 may store a history of temperature changes in each battery cell 151. This allows the CPU 211 of the ECU 210 to grasp the history of temperature distribution for each battery cell 151 using the data in the memory 120. When the charger 20 and the power storage device 10 are used in an environment other than a vehicle, the temperature distribution of the battery cells 151 may become uneven depending on the environment. For example, when the power storage device 10 is charged using the charger 20 next to a bonfire, only one side of the power storage device 10 is heated by the fanned fire. In this way, even when the temperatures of the battery cells 151 vary partially, the history of temperature distribution for each battery cell 151 can be grasped.

[0030] Furthermore, memory 120 may be configured to store information that prohibits charging of battery 150. When information that prohibits charging of battery 150 is stored in memory 120, ECU 210 controls switch drive unit 231 to turn switch 130 to an OFF state, thereby disabling charging.

[0031] In this way, by providing the power storage device 10 with the memory 120, the charger 20 can execute charging control according to the state of the battery cells 151. Furthermore, a device other than the charger 20 to which the power storage device 10 is connected (for example, a device that uses the power of the power storage device 10, or a device that charges and discharges power such as an inverter that controls a motor) may use the information stored in the memory 120 of the power storage device 10 to control charging and discharging of power.

[0032] The energy storage device 10 may have a function of equalizing the cell voltages of the multiple battery cells 151, or may have a function of equalizing and discharging the multiple battery cells 151 in consideration of variations in the cell voltages OCV and full charge capacities of the individual cells. The energy storage system 1 may have a function of including an energy storage device inside the charger 20 and transferring the equalizing discharge power of a certain battery cell 151 to another battery cell 151 with a lower voltage via the energy storage device. This allows the variations in the charge power of the battery cells 151 to be equalized, thereby maximizing the output power of the energy storage device 10. When the equalizing discharge power is transferred to the low-voltage battery cells 151, there are concerns that the energy storage device 10 will become larger due to the energy storage device used for equalization and that the equalization time will be longer. However, by installing the energy storage device next to the charger 20, it becomes easier to increase the size of the circuit including the energy storage device used for equalization, and the increase in the size of the equalization circuit also makes it possible to shorten the time required for equalization.

[0033] The CPU 211 of the ECU 210 may perform the following operations using information such as whether or not a home solar battery such as solar panel 70 is installed, whether or not the current period is one in which solar power generation is subject to preferential purchase under the Feed-in Tariff (FIT) system, the purchase rate for solar power generation, the electricity price rate from the electric power company, information from a Home Energy Management System (HEMS) (e.g., the surplus power status of solar power generation and past power generation history), information acquired through an Internet connection using an Internet of Things (IoT) function (e.g., weather forecast), and changes in power consumption over time and seasons at the location where the power storage system 1 is installed (e.g., a home, a vehicle, etc.). For example, the CPU 211 may compare the surplus solar power generation with the solar power generation buying and selling price to determine the timing of charging so that the electricity rate until the battery 150 is fully charged is the optimal economical electricity rate. The CPU 211 may also determine the timing of charging by taking into account an estimate of the surplus power generation from a weather forecast until the charging completion time. The CPU 211 may be configured to perform charge completion time management for unspecified power storage devices 10, along with management of charging power that is expected to be highly economical. If the specifications and structure of the household power source allow, the CPU 211 may control charging so as to realize an optimal economical household electricity rate by supplying the stored power of the power storage device 10 to the household power source. When the timer time management setting for the power storage device 10 is set to a setting such as "no next use planned" or a relatively long charging time setting such as "use planned in one week," the power storage device 10 may be configured to function as a household power storage device. The power storage device 10 may be used as a backup power source for household power, or as a power storage device for using surplus generated power from household power at night after the FIT period has ended.

[0034] [Second embodiment] The first embodiment shows a case where the power storage system 1A is provided with one power storage device 10. The second embodiment shows a case where the power storage system 1A is provided with a plurality of power storage devices 10.

[0035] Fig. 2 is a diagram showing an outline of the configuration of a power storage system 1A of the second embodiment. With reference to Fig. 2, in the second embodiment, differences from the first embodiment will be described, and overlapping description will not be repeated.

[0036] Charger 21 has a plurality of power output terminals 241A, 242A and power output terminals 241B, 242B instead of power output terminals 241, 242 of charger 20 of the first embodiment. Signal terminals 240A, 240B each include terminals similar to signal terminals 243 to 246. Signal terminals 140A, 140B each include terminals similar to signal terminals 143 to 146. Power storage devices 10A, 10B have the same configuration as power storage device 10 of the first embodiment. The batteries 150A, 150B, memories 120A, 120B, switches 130A, 130B, positive power terminals 141A, 141B, and negative power terminals 142A, 142B are similar to the battery 150, memory 120, switch 130, positive power terminal 141, and negative power terminal 142 of the storage device 10 of the first embodiment, respectively.

[0037] Power output terminal 242A and power output terminal 241B are directly connected by an electric wire. This connects batteries 150A and 150B in series to charger 21. As a result, when the number of power storage devices 10A and 10B connected to charger 21 is N (N=2 in this embodiment), the voltage between power terminals 141A and 142A and the voltage between power terminals 141B and 142B can be set to 1 / N of the voltage required in the vehicle and output from power conversion unit 250. In this way, the voltage between power terminals 141A and 142A and the voltage between power terminals 141B and 142B of portable power storage devices 10A and 10B can be set to 1 / N of the voltage required in the vehicle. As a result, power storage devices 10A and 10B can be transported at a relatively low voltage.

[0038] Furthermore, by setting the voltage between power terminals 141A and 142A of power storage devices 10A and 10B and the voltage between power terminals 141B and 142B to a common divisor of the voltage used in the vehicle and the voltage used outside the vehicle, power storage devices 10A and 10B can be flexibly used not only in the vehicle but also in places other than the vehicle. For example, if the voltage used in the vehicle is 360 V and the voltage used outside the vehicle is 24 V, by setting the voltage between power terminals 141A and 142A of power storage devices 10A and 10B and the voltage between power terminals 141B and 142B of power storage devices 10A and 10B to a common divisor of 12 V, power storage devices 10A and 10B can be used in series at a rate of 24 / 12 (=2 units) outside the vehicle, and power storage devices 10A and 10B can be used in series at a rate of 360 / 12 (=30 units) inside the vehicle. Furthermore, the number of battery cells 151 connected in series inside the batteries 150A and 150B can be easily and flexibly changed.

[0039] Furthermore, when operating more than the required number of power storage devices 10A, 10B such that spare power storage devices 10A, 10B are prepared in advance, the power storage devices 10A, 10B do not further include an ECU, a switch driving unit 231, a voltage conversion unit 232, a temperature conversion unit 233, and a current conversion unit 234, thereby contributing to VE (Value Engineering).

[0040] Furthermore, since a plurality of power storage devices 10A, 10B are used in combination, it is expected that the deterioration states of batteries 150A, 150B will vary. For this reason, memories 120A, 120B may be assigned identification information (e.g., an ID number) for identifying power storage devices 10A, 10B. The battery states for each piece of identification information for power storage devices 10A, 10B may be stored in memory 212 of ECU 210 of charger 21, or may be transmitted from communication unit 213 of ECU 210 of charger 21 to an external server and managed by the server. This makes it possible to manage the battery states of a plurality of power storage devices 10A, 10B.

[0041] [Third embodiment] In the second embodiment, the plurality of power storage devices 10A, 10B are connected in series when connected to the charger 21. In the third embodiment, the plurality of power storage devices 10A, 10B are connected in parallel when connected to the charger 22.

[0042] Fig. 3 is a diagram showing an outline of the configuration of a power storage system 1B of the third embodiment. With reference to Fig. 3, in the third embodiment, differences from the second embodiment will be described, and overlapping description will not be repeated.

[0043] Power output terminals 241A, 241B are directly connected by an electric wire. Power output terminals 242A, 242B are directly connected by an electric wire. This connects power storage devices 10A, 10B in parallel to charger 22. As a result, a plurality of power storage devices 10A, 10B can be charged in parallel with the output voltage of power conversion unit 250.

[0044] [Fourth embodiment] In the second embodiment, the switches 130A and 130B are provided in the power storage devices 10A and 10B. In the fourth embodiment, the switch 230 is provided in the charger 23.

[0045] Fig. 4 is a diagram showing an outline of the configuration of a power storage system 1C of the fourth embodiment. With reference to Fig. 4, in the fourth embodiment, differences from the second embodiment will be described, and overlapping description will not be repeated.

[0046] In the second embodiment, the power storage devices 10A and 10B are provided with switches 130A and 130B, respectively. In the fourth embodiment, as shown in Fig. 4, the power storage devices 11A and 11B are not provided with switches.

[0047] On the other hand, in the second embodiment, the charger 21 does not include a configuration such as the switch 130. In the fourth embodiment, as shown in Fig. 4, the charger 22 further includes a switch 230. The switch 230 is provided on an electric wire between the power conversion unit 250 and the power output terminal 241A. The switch 230 is driven by a switch drive unit 231 to switch between a connection state in which a current flows between the power conversion unit 250 and the power output terminal 241A, and a cut-off state in which a current does not flow between the power conversion unit 250 and the power output terminal 241A.

[0048] As a result, in the second embodiment, the power storage system 1A requires a plurality of switches 130A and 130B, whereas in the fourth embodiment, the power storage system 1C only requires one switch 230. As a result, it is possible to reduce the cost of providing switches in the power storage system 1C.

[0049] [Fifth embodiment] In the third embodiment, the switches 130A and 130B are provided in the power storage devices 10A and 10B. In the fifth embodiment, the switch 230 is provided in the charger 24.

[0050] Fig. 5 is a diagram showing an outline of the configuration of a power storage system 1D of the fifth embodiment. With reference to Fig. 5, in the fifth embodiment, differences from the third embodiment will be described, and overlapping description will not be repeated.

[0051] In the third embodiment, the power storage devices 10A and 10B are provided with switches 130A and 130B, respectively. In the fifth embodiment, as shown in Fig. 5, the power storage devices 11A and 11B are not provided with switches.

[0052] On the other hand, in the third embodiment, the charger 22 does not include a configuration such as the switch 130. In the fifth embodiment, as shown in Fig. 5, the charger 24 further includes a switch 230. The switch 230 is provided on an electric wire between the power conversion unit 250 and the power output terminal 241A. The switch 230 is driven by a switch drive unit 231 to switch between a connection state in which a current flows between the power conversion unit 250 and the power output terminal 241A, and a cut-off state in which a current does not flow between the power conversion unit 250 and the power output terminal 241A.

[0053] As a result, in the third embodiment, the power storage system 1B requires a plurality of switches 130A and 130B, whereas in the fifth embodiment, the power storage system 1D only requires one switch 230. As a result, it is possible to reduce the cost of providing switches in the power storage system 1D.

[0054] [Other variations] (1) As shown in Figures 1 to 5, the power storage devices 10, 10A, 10B, 11A, and 11B are detachable from the vehicle, while the chargers 20 to 24 are not mounted on the vehicle. However, the present invention is not limited to this, and the chargers 20 to 24 may be mounted on the vehicle.

[0055] (2) In the above-described embodiment, the battery cells 151 of the battery 150 are connected in series. However, this is not limiting, and the battery cells 151 may be connected in parallel, or may be connected in both series and parallel.

[0056] (3) In the above-described embodiment, the power conversion unit 250 is capable of receiving input of DC power and AC power as shown in Figures 1 to 5. However, this is not limiting, and the power conversion unit 250 may be configured to be capable of receiving input of either DC power or AC power.

[0057] (4) The above disclosure can be understood as a disclosure of the power storage system 1, 1A to 1D, the power storage device 10, 10A, 10B, 11A, 11B, or the charger 20 to 24, or as a disclosure of a power storage method using the power storage system 1, 1A to 1D, the power storage device 10, 10A, 10B, 11A, 11B, or the charger 20 to 24.

[0058] [summary] (1) As shown in FIGS. 1 to 5, power storage systems 1, 1A to 1D are systems including power storage devices 10, 10A, 10B, 11A, and 11B that are detachable from vehicles and chargers 20 to 24 that are connectable to power storage devices 10, 10A, 10B, 11A, and 11B. As shown in Figures 1 to 5, power storage devices 10, 10A, 10B, 11A, and 11B include at least one battery cell 151, a first power terminal (e.g., power terminals 141, 142, 141A, 142A, 141B, and 142B) that inputs and outputs power (e.g., DC power of a predetermined voltage) from battery cell 151, memories 120, 120A, and 120B that store information about battery cell 151, and first signal terminals (e.g., signal terminals 143-146, 140A, and 140B) that transmit and receive an analog voltage signal indicating the voltage of battery cell 151, an analog temperature signal indicating the temperature of battery cell 151, and input / output data of memories 120, 120A, and 120B between chargers 20-24.

[0059] As shown in FIGS. 1 to 5 , chargers 20 to 24 include second signal terminals (e.g., signal terminals 243 to 246, 240A, 240B) for transmitting and receiving voltage signals, temperature signals, and input / output data to and from power storage devices 10, 10A, 10B, 11A, and 11B, second power terminals (e.g., power output terminals 241, 242, 241A, 242A, 241B, 242B) for outputting power to power storage devices 10, 10A, 10B, 11A, and 11B, and third power terminals (e.g., AC power input terminals 261 to 263) for inputting power from a power source (e.g., AC power source 50, DC power source 30, solar panel 70). , DC power input terminals 251, 252), a power conversion unit 250 that converts power input from the third power terminal (for example, AC power or DC voltage of a predetermined input voltage) into power output from the second power terminal (for example, DC power of the charging voltage of the battery 150), a current conversion unit 234 that converts an analog current signal indicating the current flowing through the battery cell 151 into digital current data, a voltage conversion unit 232 that converts a voltage signal into digital voltage data, a temperature conversion unit 233 that converts a temperature signal into digital temperature data, and an ECU 210 that processes the current data, voltage data, and temperature data.

[0060] As a result, ECU 210 for controlling power storage devices 10, 10A, 10B, 11A, and 11B is included in chargers 20-24. Power storage devices 10, 10A, 10B, 11A, and 11B can be made lighter and smaller than when power storage devices 10, 10A, 10B, 11A, and 11B include ECU 210. As a result, power storage devices 10, 10A, 10B, 11A, and 11B can be made easier to carry.

[0061] Furthermore, memories 120, 120A, and 120B enable management of the status of each power storage device with a minimum configuration and manufacturing cost. Furthermore, compared to providing relatively expensive components such as switch driver 231, voltage converter 232, temperature converter 233, and current converter 234 on the power storage device 10, 10A, 10B, and 11A and 11B side, providing these components on the charger 20-24 side reduces costs and eliminates wasteful usage of these components even when multiple power storage devices 10, 10A, 10B, and 11A and 11B are owned. Furthermore, while power storage device 10 can be used for multiple purposes, such as in a vehicle or other electrical equipment, reducing costs makes it easier to purchase additional power storage devices 10, 10A, 10B, 11A, and 11B and to replace deteriorated power storage devices 10, 10A, 10B, 11A, and 11B.

[0062] Furthermore, when the configuration of switch driving unit 231, voltage conversion unit 232, temperature conversion unit 233, or current conversion unit 234 is provided on the side of chargers 20-24, if memory 120 is not provided on the side of power storage devices 10, 10A, 10B, 11A, and 11B, the information stored in memory 120 must be stored on the side of chargers 20-24. For this reason, it is necessary to have a one-to-one relationship between chargers 20-24 and power storage devices 10, 10A, 10B, 11A, and 11B. However, since memory 120 is provided on the side of power storage devices 10, 10A, 10B, 11A, 11B, even if the configuration of switch drive unit 231, voltage conversion unit 232, temperature conversion unit 233, or current conversion unit 234 is provided on the side of chargers 20 to 24, power storage devices 10, 10A, 10B, 11A, 11B can also be charged by other chargers 20 to 24.

[0063] (2) As shown in Figures 2 to 5, chargers 20 to 24 may be configured to be connectable to a plurality of power storage devices. This allows the ratio of the volume and weight of the portions other than battery cells 151 to the combined volume and weight of multiple power storage devices 10A, 10B, 11A, and 11B to be even lighter and smaller than when ECU 210 is included in each of multiple power storage devices 10A, 10B, 11A, and 11B.

[0064] 1 to 5, ECU 210 may control power conversion unit 250 to charge power storage devices 10, 10A, 10B, 11A, and 11B using information about battery cells 151 indicated by input / output data. As a result, even when ECU 210 controlling power storage devices 10, 10A, 10B, 11A, and 11B is provided in chargers 20 to 24, it is possible to appropriately control charging power storage devices 10, 10A, 10B, 11A, and 11B using information about each battery cell 151 of power storage devices 10, 10A, 10B, 11A, and 11B.

[0065] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the description of the above embodiments, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0066] 1, 1A, 1B, 1C, 1D, 9 Energy storage system, 10, 10A, 10B, 11A, 11B, 80 Energy storage device, 20-24, 90 Charger, 30 DC power supply, 31, 32, 51, 53, 71, 72 Output terminal, 50 AC power supply, 70 Solar panel, 120, 120A, 120B, 212, 812, 912 Memory, 130, 130A, 130B, 230, 830 Switch, 140A, 140B, 143-146, 240A, 240B, 243-246, 843, 943 Signal terminal, 141, 141A, 141B, 142, 142A, 142B, 841, 842 Power terminal, 150, 150A, 150B, 850 Battery, 151, 851 Battery cell, 152, 852 Voltage sensor, 153, 853 Temperature sensor, 210, 810, 910 ECU, 211, 811, 911 CPU, 213, 813, 913 Communication unit, 231, 831 Switch drive unit, 232, 832 Voltage conversion unit, 233, 833 Temperature conversion unit, 234, 834 Current conversion unit, 235, 835 Current sensor, 241, 241A, 241B, 242, 242A, 242B, 941, 942 Power output terminal, 250, 950 Power conversion unit, 251, 252, 951, 952 DC power input terminal, 261,263,961,963 AC power input terminal.

Claims

1. A power storage system including a power storage device detachable from a vehicle and a charger connectable to the power storage device, The power storage device is at least one battery cell; a first power terminal for inputting and outputting power from the battery cell; a memory that stores information about the battery cell; a first signal terminal for transmitting and receiving an analog voltage signal indicating a voltage of the battery cell, an analog temperature signal indicating a temperature of the battery cell, and input / output data of the memory to and from the charger; The charger includes: a second signal terminal for transmitting and receiving the voltage signal, the temperature signal, and the input / output data to and from the power storage device; a second power terminal for outputting power to the power storage device; a third power terminal for receiving power from a power source; a power conversion unit that converts power input from the third power terminal into power output from the second power terminal; a current conversion unit that converts an analog current signal indicating a current flowing through the battery cell into digital current data; a voltage conversion unit that converts the voltage signal into digital voltage data; a temperature conversion unit that converts the temperature signal into digital temperature data; an electronic control unit that processes the current data, the voltage data, and the temperature data.

2. The power storage system according to claim 1 , wherein the charger is connectable to a plurality of the power storage devices.

3. The power storage system according to claim 1 , wherein the electronic control unit controls the power conversion unit to charge the power storage device using information about the battery cell indicated by the input / output data.

4. A power storage device that is detachable from a vehicle, at least one battery cell; a power terminal for inputting and outputting power from the battery cell; a memory that stores information about the battery cell; an analog voltage signal indicating the voltage of the battery cell, an analog temperature signal indicating the temperature of the battery cell, and a signal terminal for transmitting and receiving input / output data of the memory to and from a charger;

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