Battery evaluation device and battery evaluation system

Abstract

To provide a storage battery evaluation system capable of relatively easily achieving evaluation of a storage battery.SOLUTION: A storage battery evaluation system includes: a storage battery evaluation device 100 that is configured to acquire storage battery evaluation data during a charging process and includes a current detection unit that detects a charging current, a voltage detection unit that detects a charging voltage, and an arithmetic unit configured to output an instruction to control a value of the charging current; and an information processing element 10 that performs data communication with the storage battery evaluation device 100. The information processing element 10 calculates battery characteristics of a storage battery 30 on the basis of the storage battery evaluation data provided from the storage battery evaluation device 100 to notify an external terminal 40 of an evaluation result according to the battery characteristics.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a battery evaluation device and a battery evaluation system.

Background Art

[0002] High reliability is required for secondary batteries (storage batteries) mounted on electric vehicles (EVs), plug-in hybrid vehicles (PHEVs), etc. The storage batteries mounted on EVs and PHEVs need to maintain their soundness over a long period of time so as not to malfunction. Therefore, in order to confirm whether the functions expected of the storage battery are maintained and the battery is in a sound state, it is necessary to evaluate the deterioration state of the storage battery.

[0003] The deterioration state of a storage battery can be evaluated by a method of measuring alternating current impedance as shown in Patent Document 1. In the method of measuring alternating current impedance, the resistance of each part of the battery is obtained from the data of the alternating current impedance measured by changing the frequency of the state detection current, and the battery deterioration is evaluated.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the battery evaluation method and device disclosed in Patent Document 1, in the evaluation of the deterioration state of a battery by the method of measuring alternating current impedance, a dedicated evaluation device for applying and detecting an alternating current signal of a predetermined frequency is used.

[0006] For example, in the case of a storage battery mounted on an EV, the chargers used in the market usually do not have the function of applying and detecting an AC signal, cannot perform measurements during the normal charging and discharging process, and a dedicated process for performing measurements and evaluations may be required. In particular, in industries such as the transportation industry where the operating time of the vehicle is directly linked to profits, the need for dedicated devices and processes for battery evaluation not only increases costs but also means a decrease in vehicle operating efficiency, which may lead to a decrease in profits and is not desirable.

[0007] One of the objectives of the present invention is to provide a device for evaluating a storage battery and a storage battery evaluation system that can relatively easily evaluate the storage battery during the charging process of the storage battery.

Means for Solving the Problem

[0008] The device for evaluating a storage battery for evaluating the state of the storage battery according to the present invention includes a current detection unit that detects a charging current, a voltage detection unit that detects a charging voltage, and an arithmetic unit connected to the current detection unit and the voltage detection unit. The arithmetic unit is configured to output an instruction for controlling the value of the charging current, and to provide battery evaluation data based on the value of the charging current and the value of the charging voltage to an external information processing element that outputs an evaluation result based on the battery evaluation data.

[0009] The device for evaluating the storage battery may be configured such that the arithmetic unit outputs an instruction for controlling the charging current to a value within a predetermined range. The value within the predetermined range may vary depending on the capacity of the storage battery. The instruction for controlling the charging current to a value within the predetermined range may be defined by a charging rate.

[0010] In the device for evaluating the storage battery, the instruction for controlling the charging current to a value within a predetermined range may be output as an instruction specifying the value of the charging current, the value of the charging power, or the C-rate.

[0011] The battery evaluation device may output an instruction to control the charging current to a value within a predetermined range, for example, an instruction to specify the C rate to 0.3 or less.

[0012] The battery evaluation device may further include a temperature detection unit, and the calculation unit may be configured to output an instruction to change the value within the predetermined range according to the temperature detected by the temperature detection unit.

[0013] The battery evaluation device may have a charger-side connector detachably connected to a connector provided in the charger, and a battery-side connector detachably connected to a connector provided in the battery unit including the battery.

[0014] The charger-side connector and the battery-side connector of the battery evaluation device may conform to the CHAdeMO standard.

[0015] The battery evaluation system for evaluating the state of a battery according to the present invention includes the battery evaluation device configured to acquire battery evaluation data during a charging process, and an information processing element that performs data communication with the battery evaluation device. The information processing element is configured to calculate the battery characteristics of the battery based on the battery evaluation data provided from the battery evaluation device, and notify an external terminal of an evaluation result according to the battery characteristics.

[0016] In the battery evaluation system, the battery characteristics may be calculated using the values of the charging voltage and the charging current as input information.

[0017] In the battery evaluation system, the evaluation result may be the maintenance rate of the charging capacity of the battery.

Advantages of the Invention

[0018] According to an embodiment of the present invention, a battery evaluation device capable of relatively easily acquiring battery evaluation data using a process of charging a battery and providing the data to an information processing element can be provided. Further, a battery evaluation system including the battery evaluation device and capable of relatively easily notifying, for example, an external terminal held by a user of the battery of an evaluation result of the battery can be provided.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0020] Hereinafter, a battery evaluation device and a battery evaluation system according to embodiments of the present invention will be described with reference to the drawings.

[0021] First, referring to FIG. 1, a battery evaluation apparatus according to the present invention and a battery evaluation system including the battery evaluation apparatus will be described. FIG. 1 schematically shows an example of a battery evaluation system including the battery evaluation apparatus of the embodiment. The battery evaluation system 100S includes a battery evaluation apparatus 100 and an information processing element 10. In the battery evaluation system 100S, the battery evaluation apparatus 100 is configured to acquire data related to the charging of the battery 30. The information processing element 10 is configured to output an evaluation result of the battery 30 based on the data related to the charging of the battery 30 acquired by the battery evaluation apparatus 100. The evaluation result of the battery 30 is notified to, for example, a terminal 40 held by a user 41 of the battery 30. In the illustrated example, the battery evaluation apparatus 100 is disposed between a charger 20 and a battery unit 31 including the battery 30, and the information processing element 10 is disposed at a position separated from the charger 20 and the battery unit 31.

[0022] The charger 20 is, for example, known electric vehicle charging equipment. Specifically, the charger 20 can be a charging stand for electric vehicles capable of rapid charging with direct current. The charger 20 includes a charge control unit 22. The battery 30 is, for example, a secondary battery mounted on an electric vehicle EV. In the illustrated example, the battery 30 is included in the battery unit 31. The battery unit 31 is configured to be able to communicate with the control unit 22 of the charger 20 regarding charging conditions and the like in a state where the battery 30 and the charger 20 are connected.

[0023] The battery unit 31 includes, for example, a battery management system (BMS) 32 configured to monitor the voltage, temperature, capacity, state of charge, power consumption, remaining operating time, etc. of the battery and protect the battery 30 from over-discharge and over-voltage caused by extreme rapid charging or extreme high discharge current, and an electronic control unit (ECU) 33 that may have a function of specifying an optimal charging current to the control unit 22 on the charger 20 side according to the state of the battery 30. The battery 30 mounted on the electric vehicle EV may be a lithium-ion battery. The battery 30 may be a lead-acid battery, a nickel-metal hydride battery, or a nickel-cadmium battery other than a lithium-ion battery.

[0024] Note that the battery 30 is not limited to the battery mounted on an electric vehicle, and may be, for example, a stationary battery for a building. The battery 30 may also be a battery in cooperation or system connection with a power generation system. In this case, the charger 20 may be a device such as a power conditioner that supplies power from the power generation system to the battery. Further, the battery 30 may be, for example, a battery of a battery-mounted device such as a drone or a mobile phone other than an electric vehicle.

[0025] The charger 20 and the battery unit 31 are, for example, compliant with the CHAdeMO (registered trademark) standard in which the control unit 22 provided in the charger 20, which is a charging stand for an electric vehicle, and the battery unit 31 of the electric vehicle EV communicate by CAN (Controller Area Network) communication. The charger 20 and the battery unit 31 may be compliant with a standard other than the CHAdeMO (registered trademark) standard, such as the CCS1 standard, the CCS2 standard, or the GB / T standard. There may be a case where the charger 20 and the battery unit 31 have different compliant standards. Hereinafter, the battery evaluation device 100 and the battery evaluation system 100S will be described by taking the case where the charger 20 and the battery unit 31 are compliant with the CHAdeMO (registered trademark) standard as an example.

[0026] The charger 20 is provided with a connector 201. The battery unit 31 is provided with a connector 301. Generally, when charging from the charger 20 to the battery 30 is performed, the connector 201 and the connector 301 are directly connected. In the illustrated example, the battery evaluation device 100 relays between the connector 201 of the charger 20 and the connector 301 of the battery unit 31, and as will be described in detail later, during the charging process from the charger 20 to the battery 30, it is configured to acquire data (battery evaluation data) for evaluating the battery 30.

[0027] Specifically, in the illustrated example, the battery evaluation device 100 includes one connector 102 and the other connector 103 on the side opposite to the one connector 102. The one connector 102 can be detachably connected to the connector 201 provided in the charger 20. The other connector 103 can be detachably connected to the connector 301 provided in the battery unit 31.

[0028] That is, the battery evaluation device 100 can be configured to be portable as a separate unit from the charger 20 and the battery 30. However, the battery evaluation device 100 may be fixedly installed with respect to the charger 20 or the battery 30. Also, the battery evaluation device 100 may be incorporated in the charger 20 or the battery unit 31. Note that the one connector 102 is also referred to as the charger-side connector 102, and the other connector 103 is also referred to as the battery-side connector 103. Here, both the charger-side connector 102 and the battery-side connector 103 conform to the CHAdeMO (registered trademark) standard.

[0029] The battery evaluation device 100 is configured to perform data communication with the information processing element 10. Specifically, battery evaluation data for evaluating the battery 30, which is acquired by the battery evaluation device 100 during the charging process of the battery 30, can be provided to the information processing element 10 by communication. The information processing element 10 can be a computer including a memory device and an arithmetic device that stores and processes the battery evaluation data. Also, the information processing element 10 can be, for example, a server and an arithmetic device on a communication network provided by a cloud service.

[0030] The battery evaluation device 100 includes a communication unit, as will be described later in detail with reference to FIG. 3. The battery evaluation data acquired by the battery evaluation device 100 can be provided to the information processing element 10 by wireless communication via this communication unit. In the communication performed between the battery evaluation device 100 and the information processing element 10, a wireless connection such as Wi-Fi (registered trademark), which connects the battery evaluation device 100 and the public wireless communication network, can be used. For the wireless connection, in addition to Wi-Fi (registered trademark), cellular LPWA (NB-IoT, LTE-M), Bluetooth (registered trademark), etc. can also be used.

[0031] In addition to the battery evaluation device 100, the information processing element 10 can also be connected to an external terminal 40 via, for example, the same communication as the above-described wireless communication. The terminal 40 can be, for example, an information terminal (e.g., a smartphone, a tablet PC, etc.) owned by the user 41 of the electric vehicle EV. In the figure, one terminal 40 is shown, but the information processing element 10 can be connected to a plurality of terminals simultaneously and perform data transmission and reception simultaneously. The information processing element 10 is configured to calculate the evaluation result of the battery 30 based on the battery evaluation data provided from the battery evaluation device 100 and provide it to the terminal 40.

[0032] The storage battery 30 may deteriorate in performance as a result of its use (repeated charge and discharge). Since the deteriorated storage battery 30 has a reduced electrical capacity etc., it may not meet the criteria required by its user. As an evaluation result representing the progress of deterioration of the storage battery 30, for example, the battery capacity retention rate (the ratio of the current electrical capacity to the initial electrical capacity) is provided to the user 41 via the terminal 40, which may make it easier for the user 41 to judge whether the storage battery 30 and the EV vehicle can be used. Also, the battery capacity retention rate of the storage battery 30 can be a reasonable criterion, for example, in setting the price when the storage battery 30 is bought and sold as a used product.

[0033] Subsequently, referring to the flowchart of FIG. 2, an outline of the process of evaluating the storage battery 30, which is performed by the storage battery evaluation system 100S when charging is carried out from the charger 20 to the storage battery 30, will be described. In FIG. 2, an outline of the process in the storage battery evaluation system 100S from the determination of the charging conditions to the output of the evaluation result of the storage battery is shown as steps S01 to S04.

[0034] First, step S01 is executed with the battery evaluation device 100 connected to the charger 20 and the battery unit 31. In step S01, the charger 20 and the battery unit 31 communicate with each other via the battery evaluation device 100, and charging conditions including the value of the charging current are controlled. Regarding the control of the charging conditions, specifically as will be described later with reference to FIG. 4, the battery evaluation device 100 outputs an instruction to control the charging current supplied from the charger 20 to the battery 30 to the battery unit 31. The determination of the charging conditions can be made by the processing in the information processing element 10. Also, the determination of the charging conditions may be made by the processing in the battery evaluation device 100. Specifically, depending on information such as the type, capacity, and rated voltage of the provided battery 30, and the temperature information in the battery evaluation device 100 provided as a reference for the environmental temperature, the information processing element 10 or the battery evaluation device 100 determines the charging conditions according to a predetermined calculation method. In this case, a database that the information processing element 10 may include, or information regarding the type, capacity, etc. of the battery 30 may be provided from the battery unit 31. After the charging conditions are determined, the supply of power (charging process) from the charger 20 to the battery 30 is started.

[0035] Next, in step S02, during the charging process, battery evaluation data including the value of the charging current and the value of the charging voltage supplied from the charger 20 to the battery 30 is acquired by the battery evaluation device 100. Depending on the calculation method of the battery characteristics, battery evaluation data within a desired range in the SOC (STATE OF CHARGE) representing the state of charge may be acquired. For example, desirably, it may be set to acquire data in the range of 30% to 90% of the SOC representing the state of charge. The acquired battery evaluation data is provided to the information processing element 10 via wireless communication through the calculation unit provided in the battery evaluation device 100. Note that the provision of the battery evaluation data to the information processing element 10 may be performed in parallel with the acquisition of the battery evaluation data during the charging process, or may be performed after the charging process is completed. The battery evaluation data may include information regarding the temperature inside the battery evaluation device 100.

[0036] Next, in step S03, battery characteristics are calculated in the information processing element 10. The calculated battery characteristics may include, for example, the remaining battery capacity and the value of the internal resistance. The battery characteristics can be calculated by analyzing the provided battery evaluation data (charging voltage and charging current). For the calculation of the battery characteristics, for example, a method of analyzing a charging curve obtained from the charging voltage (hereinafter, the charging curve analysis method) described in "Tomokazu Morita et al., 'Charging Curve Analysis Method for Visualizing Battery Health by Estimating Internal State', Toshiba Review Vol. 68 No. 10, 2013, p. 54 - 57" can be used.

[0037] Next, in step S04, the evaluation result of the storage battery 30 is output toward the external terminal 40. The evaluation result can be, for example, the maintenance rate of the battery capacity calculated in the information processing element 10 based on the battery characteristics calculated in step S03. Note that the battery characteristics may be output to the terminal 40 as the evaluation result as it is.

[0038] In the storage battery evaluation system of the embodiment, it is possible to acquire data for battery evaluation in parallel with the charging process of the storage battery by the battery evaluation device without requiring a dedicated evaluation process. The data for battery evaluation obtained in parallel with the charging process is processed by the information processing element in parallel with the charging process and converted into an evaluation result indicating the deteriorated state of the battery, such as the battery capacity maintenance rate, which can be notified to an external terminal. Therefore, in the storage battery evaluation system of the embodiment, a configuration including a battery evaluation device capable of acquiring data for battery evaluation during the charging process realizes a configuration in which the evaluation of the storage battery can be relatively easily performed. As a result, it becomes possible to evaluate the storage battery at a relatively high frequency, and thus the possibility of capturing undesirable situations such as abnormal deterioration of the storage battery can be increased.

[0039] The battery evaluation system according to the embodiment has a configuration in which the battery evaluation device outputs an instruction to control the charging current value, so that it is possible to obtain battery evaluation data more suitable for evaluation by keeping the charging current value relatively low. Further, the evaluation result is output to an external terminal through, for example, an information processing element provided by a cloud service, so that it is also possible to notify the evaluation result to a plurality of terminals at the same time, and it is relatively easy to share the evaluation result among a plurality of interested parties (for example, battery users, maintenance personnel, etc.). When the battery evaluation system includes a portable battery evaluation device that relays the charger and the battery detachably, the degree of freedom in selecting the location for performing the battery evaluation is improved, and thus, the simplicity of performing the battery evaluation can be further improved.

[0040] Subsequently, the battery evaluation device 100 included in the battery evaluation system 100S according to the embodiment will be described with reference to FIG. 3. FIG. 3 shows an example of the internal configuration of the battery evaluation device 100 that relays the charger 20 and the battery unit 31 illustrated in FIG. 1 and is detachably installed with respect to the charger 20 and the battery unit 31. The battery evaluation device 100 includes a current detection unit 111 that detects the value of the charging current supplied to the battery 30 during the charging process of the battery, and a voltage detection unit 112 that detects the value of the charging voltage applied to the battery 30 during the charging process of the battery. The battery evaluation device 100 further includes an arithmetic unit 110 connected to the current detection unit 111 and the voltage detection unit 112.

[0041] The current detection unit 111 and the voltage detection unit 112 perform the acquisition of the battery evaluation data in step S02 (see FIG. 2) described above. The current detection unit 111 can detect the value of the charging current (the current supplied from the charger 20 to the battery 30) at a predetermined time interval from the start to the end of charging during the charging process and provide it to the arithmetic unit 110. The voltage detection unit 112 can detect the value of the charging voltage (the voltage supplied from the charger 20 to the battery 30) at a predetermined time interval from the start to the end of charging during the charging process and provide it to the arithmetic unit 110.

[0042] In the illustrated example, the battery evaluation device 100 includes a power supply line 120 that relays between the charger-side connector 102 and the battery-side connector 103. The power supply line 120 conveys the power supplied from the charger 20 to the battery 30. The current detection unit 111 detects the value of the charging current flowing through the power supply line 120 during the charging process. The voltage detection unit 112 detects the value of the charging voltage applied to the power supply line 120 during the charging process. The value of the charging current and the value of the charging voltage provided to the arithmetic unit 110 are output to the communication unit 113, and the communication unit 113 provides the value of the charging current and the value of the charging voltage to the information processing element 10 as battery evaluation data.

[0043] The communication unit 113 that the battery evaluation device 100 may include is configured to transmit and receive data to and from the information processing element 10. For example, when determining the charging conditions in step S01 (see FIG. 2) described above, the communication unit 113 receives reference data (such as the type and capacity of the battery 30) from the information processing element 10. Also, corresponding to step S02 (see FIG. 2) described above, the communication unit 113 performs the transmission of the battery evaluation data provided from the current detection unit 111 and the voltage detection unit 112 to the information processing element 10 via the arithmetic unit 110. The communication unit 113 may be, for example, a wireless router that conforms to a wireless connection standard such as the above-mentioned Wi-Fi (registered trademark). The communication unit 113 may be configured to be able to directly transmit and receive data with an external terminal 40.

[0044] In the arithmetic unit 110, arithmetic processing related to the determination of the charging conditions in step S01 (see FIG. 2) described above may be performed. The arithmetic unit 110 may perform arithmetic processing related to the determination of the charging conditions optimal for the evaluation of the battery 30, for example, based on information such as the type and capacity of the battery 30 that may be provided from the information processing element 10 or the battery unit 31. Regarding the determined charging conditions, the communication between the control unit 22 on the charger 20 side and the battery unit 31 may be performed via the arithmetic unit 110.

[0045] When the connectors (charger-side connector 102 and battery-side connector 103) of the battery unit 31, the charger 20, and the battery evaluation device 100 conform to the CHAdeMO (registered trademark) standard, communication between the control unit 22 on the charger 20 side via the arithmetic unit 110 and the battery unit 31 can be carried out by CAN communication. Therefore, in the example of the battery evaluation device shown in the figure, in order to carry out CAN communication between the battery unit 31 and the charger 20 via the arithmetic unit 110, a battery-side communication line 131, a battery-side CAN transceiver 131t, a charger-side communication line 132, and a charger-side CAN transceiver 132t are provided. The battery-side CAN transceiver 131t is connected to the battery-side communication line 131 and the arithmetic unit 110, and the charger-side CAN transceiver 132t is connected to the charger-side communication line 132 and the arithmetic unit 110.

[0046] The battery evaluation device 100 may include a temperature detection unit 114 that detects the temperature inside the battery evaluation device 100. In the determination of the charging conditions in the above-described step S01 (see FIG. 2), the temperature inside the battery evaluation device 100 may be referred to in the arithmetic processing related to the determination of the charging conditions. Also, in the calculation of the battery characteristics in the above-described step S03 (see FIG. 2), the temperature inside the battery evaluation device 100 is referred to as battery evaluation data. The temperature inside the battery evaluation device 100 detected by the temperature detection unit 114 can be provided to the arithmetic unit 110. The temperature detection unit 114 may include a temperature sensor such as a thermocouple or a thermistor, for example.

[0047] When the battery evaluation device is the battery evaluation device 100 in a mode that relays between the charger 20 conforming to the CHAdeMO (registered trademark) standard and the battery unit 31, as shown in the figure, the battery evaluation device 100 may include five lines (lines La to Le) for signaling the connection state between the charger 20 and the battery unit 31. The line La connecting the terminal 102a and the terminal 103a is a wiring for transmitting a signal related to the start / stop of charging. The line Lb connecting the terminal 102b and the terminal 103b is a wiring for transmitting a signal related to the permission / prohibition of charging. The line Lc connecting the terminal 102c and the terminal 103c is a wiring for transmitting a signal related to the confirmation of the connector connection. The line Ld connecting the terminal 102d and the terminal 103d is a wiring for transmitting a signal related to the start / stop of charging. The line Le connecting the terminal 102e and the terminal 103e is a wiring connected to the ground wire.

[0048] Next, with reference to the flowchart of FIG. 4, an example of a specific process in the determination of the charging conditions in step S01 (see FIG. 2) described above will be explained. In the flowchart of FIG. 4, the specific procedures for implementing the determination of the charging conditions are shown as steps S011 to S014.

[0049] First, in step S011, vehicle data including information on the vehicle type and model year of the electric vehicle EV equipped with the battery 30 is provided to the information processing element 10. The vehicle data is provided to the battery evaluation device 100 from the battery unit 31 by CAN communication, for example, and transmitted to the information processing element 10 via the communication unit 113. Further, the provision of the vehicle data to the information processing element 10 may be performed by the input of the user 41 from the terminal 40 owned by the user 41 of the electric vehicle EV, for example.

[0050] Next, in S012, the type of the storage battery 30 included in the electric vehicle EV is specified. Specifically, in the information processing element 10, the vehicle data provided in step S011 is collated with the vehicle information data (information in which the vehicle type and model year correspond to the type of the storage battery) stored in the database that the information processing element 10 may include, the type of the storage battery 30 included in the electric vehicle EV is specified, and the basic information (such as battery capacity and rated voltage) of the storage battery 30 is acquired. In steps S011 to S012, in some cases, the temperature information in the storage battery evaluation device 100 is also provided to the information processing element 10.

[0051] Next, in S013, in the information processing element 10, based on the basic information of the storage battery 30 obtained in S012, the charging conditions including the charging current value and the charging speed are determined. When determining the charging conditions, the validity as the storage battery evaluation data in the above-described step S02 (see FIG. 2) is considered, and the charging current is determined to be a value within a predetermined range. Note that the determination of the charging conditions may be performed by the processing in the arithmetic unit 110 of the storage battery evaluation device 100. When determining the charging conditions, the charging conditions may be determined according to the temperature in the storage battery evaluation device 100 provided from the storage battery evaluation device 100.

[0052] Next, in S014, an instruction to control the charging current to the determined charging conditions is output from the storage battery evaluation device 100. Specifically, for example, the charging conditions determined in the information processing element 10 in step S013 are provided to the arithmetic unit 110 of the storage battery evaluation device 100 via the communication unit 113. The arithmetic unit 110 outputs an instruction to control the value of the charging current supplied from the charger 20 to the storage battery 30 so as to conform to the provided charging conditions. The instruction to control the charging current to a value within a predetermined range may be output as an instruction specifying the value of the charging current, the value of the charging power, or the C-rate. When the instruction to control the charging current to a value within a predetermined range is provided as the specification of the C-rate, it is preferable to output an instruction to set the C-rate to 0.3 or less. For example, when the storage battery 30 has a capacity of 40 kWh and a rated voltage of 350 V, the C-rate is set to 0.2 or less, that is, the charging current is set to 22.8 A or less.

[0053] For example, the calculation unit 110 of the battery evaluation device 100 converts the information on the maximum value of the charging current that can be supplied from the charger 20, which is notified to the battery unit 31 by CAN communication from the control unit 22 of the charger 20, so as to match the charging current value under the determined charging conditions. The converted information on the maximum value of the available charging current is transmitted to the battery unit 31 by CAN communication. In this case, an instruction is output from the battery unit 31 to the control unit 22 of the charger 20 to request supplying a current value that matches the provided maximum value of the available charging current. In response to this instruction from the battery unit 31, a charging process under the determined charging conditions is started from the charger 20 to the battery 30. In short, the calculation unit 110 of the battery evaluation device 100 outputs an instruction for controlling the value of the charging current toward the battery unit 31 according to the determined charging conditions. As a result, in the charging process, a charging current with a value that conforms to the determined charging conditions is supplied from the charger 20 to the battery 30.

[0054] Subsequently, with reference to the flowchart of FIG. 5, an example of a specific process in the calculation of the battery characteristics in step S03 (see FIG. 2) described above is explained. In the flowchart of FIG. 5, the process of calculating the battery characteristics is shown as steps S031 to S034.

[0055] In the description with reference to FIG. 5, as a method for analyzing the charging voltage value obtained as battery evaluation data, an example in which battery characteristics are calculated by a charging curve analysis method is explained. The charging curve analysis method uses values such as charging current, charge amount, charging voltage, and temperature (battery evaluation data) during a predetermined charging time as input information, and uses a function representing the relationship between the charge amount of the active material contained in the battery and the charging voltage to estimate internal state quantities including positive electrode capacity, positive electrode diffusion resistance, positive electrode electrolyte ion concentration, negative electrode capacity, negative electrode diffusion resistance, negative electrode electrolyte ion concentration, ohmic resistance + reaction resistance, etc., and calculates battery characteristics such as battery capacity and internal resistance based on the estimation results of these internal state quantities.

[0056] First, in step S031, for example, in the information processing element 10, the internal state quantity in the initial state of the storage battery 30 stored in the database that the information processing element 10 may have, or the internal state quantity obtained in the past evaluation, is referred to and set as the initial value. Based on this initial value of the internal state quantity, a model curve representing the charging voltage value with respect to the charging time or the charging amount, which is used in the fitting calculation in step S033, is obtained.

[0057] Next, in step S032, in the information processing element 10, based on the battery evaluation data provided from the battery evaluation device 100 in step S02 (see FIG. 2) described above, a charging curve representing the charging voltage value with respect to the charging time or the charging amount is obtained.

[0058] Next, in step S033, the charging curve obtained based on the battery evaluation data and the model curve obtained based on the initial value of the internal state quantity are subjected to fitting calculation. Specifically, a calculation for estimating the parameter of the internal state quantity that minimizes the residual between the charging curve and the model curve is performed. An estimated value of the internal state quantity of the storage battery 30 is obtained. In the fitting calculation, for example, data on the relationship between the open-circuit potential and the charging amount for each active material that can be used for the electrodes of the storage battery, data on the internal resistance, and information on their temperature dependencies, etc., stored in the database provided in the information processing element 10, can be referred to. The temperature inside the battery evaluation device 100 can also be referred to.

[0059] Next, in step S034, based on the estimated value of the internal state quantity of the storage battery 30 obtained in step S033, the battery characteristics of the storage battery 30, which may include the battery capacity and the internal resistance of the storage battery 30, etc., are calculated. The battery characteristics calculated here are, for example, converted into a battery capacity maintenance rate in step S04 (see FIG. 2) described above, and can be notified to the external terminal 40 as the evaluation result of the storage battery. In some cases, the battery characteristics calculated here may be output as the evaluation result as they are.

[0060] The battery evaluation system of the embodiment is not limited to the battery evaluation system described above with reference to the respective drawings. The method for calculating battery characteristics implemented in the battery evaluation system of the embodiment is not limited to the procedure based on the charge curve analysis method described above. For example, the calculation of the internal state quantity of the storage battery 30 may be performed by the arithmetic unit 110 of the battery evaluation device 100. In this case, the calculated internal state quantity may be provided as battery evaluation data from the battery evaluation device 100 to the information processing element 10. Further, when temperature data in the vicinity of the storage battery 30 is provided from the storage battery unit 31 to the battery evaluation device 100, particularly in determining the charging conditions in step S01, the temperature data provided from the storage battery unit 31 may be referred to in preference to the temperature detected by the temperature detection unit 114. Further, an external terminal 40 may be interposed in the communication between the battery evaluation device 100 and the information processing element 10. For example, the provision of battery evaluation data from the battery evaluation device 100 to the information processing element 10 may be performed via the terminal 40, and the charging conditions determined in the information processing element 10 may also be provided to the battery evaluation device 100 via the terminal 40.

Description of Signs

[0061] 10 Information processing element 20 Charger 22 Control unit 30 Storage battery 31 Storage battery unit 40 Terminal 41 User 100 Battery evaluation device 100S Battery evaluation system 102 Connector (charger side connector) 103 Connector (storage battery side connector) 110 Arithmetic unit 111 Current detection unit 112 Voltage detection unit 113 Communication unit 114 Temperature detection unit 120 Power supply line 131 Storage battery side communication line 132 Charger-side communication line 131t Battery-side CAN transceiver 132t Charger-side CAN transceiver EV Electric vehicle

Claims

1. A battery evaluation device for evaluating the state of a battery, comprising: a current detection unit that detects a charging current; a voltage detection unit that detects a charging voltage; an arithmetic unit connected to the current detection unit and the voltage detection unit; and the arithmetic unit is configured to output an instruction for controlling the value of the charging current based on a determined charging condition, and to provide battery evaluation data based on the value of the charging current and the value of the charging voltage to an external information processing element that outputs an evaluation result based on the battery evaluation data. A battery evaluation device having a charger-side connector that is detachably connected to a connector included in a charger, and a battery-side connector that is detachably connected to a connector included in a battery unit including the battery, and configured to be portable as a single unit.

2. The battery evaluation device according to claim 1, wherein the arithmetic unit is configured to output an instruction for controlling the charging current to a value within a predetermined range.

3. The battery evaluation device according to claim 2, wherein the instruction for controlling the charging current to a value within a predetermined range is output as an instruction for specifying the value of the charging current, the value of the charging power, or the C-rate.

4. The battery evaluation device according to claim 3, wherein the instruction for controlling the charging current to a value within a predetermined range is output as an instruction for specifying a C-rate of 0.3 or less.

5. The battery evaluation device according to claim 2, further comprising a temperature detection unit, and the arithmetic unit is configured to output an instruction for changing the value within the predetermined range according to the temperature detected by the temperature detection unit.

6. The battery evaluation device according to claim 1, wherein the charger-side connector and the battery-side connector conform to the CHAdeMO standard.

7. A battery evaluation system for evaluating the state of a battery, comprising: the battery evaluation device according to claim 1, configured to acquire battery evaluation data during a charging process; an information processing element that performs data communication with the battery evaluation device; and the information processing element is configured to calculate battery characteristics of the battery based on the battery evaluation data provided from the battery evaluation device, and notify an external terminal of an evaluation result according to the battery characteristics.

8. The battery evaluation system according to claim 7, wherein the battery characteristics are calculated using the value of the charging voltage and the value of the charging current as input information.

9. The battery evaluation system according to claim 7, wherein the evaluation result is the maintenance rate of the charging capacity of the storage battery.

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