Battery analysis system, battery analysis method, and battery analysis program

Abstract

A map generation unit (113) generates a battery characteristic map including the deterioration index value on a condition axis on the basis of battery data of secondary batteries (E1 to En) of the same type acquired from a plurality of battery packs. A map evaluation value calculation unit (114) calculates an evaluation value indicating the degree of completeness of the battery characteristic map. A map transmission unit (115) skips transmission of the latest version of the battery characteristic map to the battery packs if the difference between the evaluation value of the battery characteristic map of the version currently used in the battery packs to which the battery characteristic map is to be transmitted and the evaluation value of the latest version of the battery characteristic map is less than or equal to a threshold value.

Description

Battery analysis system, battery analysis method, and battery analysis program

[0001] The present disclosure relates to a battery analysis system, a battery analysis method, and a battery analysis program that collect battery data and generate a common battery characteristic map.

[0002] One possible operation is to upload data measured by each BMU (Battery Management Unit) of multiple battery packs installed in mobility devices such as electric bicycles, electric motorcycles, and electric kick scooters to a cloud server to generate common control data. For example, the cloud server may generate internal resistance maps for each temperature and SOC (State Of Charge), and the BMU of each battery pack may download the internal resistance map from the cloud server and use it for highly accurate SOC estimation.

[0003] Considering the amount of communication, it is desirable to reduce the frequency of downloading the internal resistance map created on the cloud server as much as possible. When the internal resistance map in the BMU is updated periodically, a new map is downloaded each time, regardless of the impact on the control in the BMU. If an update has a large impact on the control in the BMU, it is desirable to download the latest map and use the latest map, but if only updates have been made that have a small impact on the control, there is little need to download the latest map and use the latest map.

[0004] Patent Literature 1 discloses a method in which a server updates a table based on data associated with battery types collected from multiple BMUs and periodically transmits the updated table to the BMUs, but does not disclose the specifics of how the table is updated.

[0005] Japanese Patent Application Laid-Open No. 2021-92464

[0006] The present disclosure has been made in consideration of these circumstances, and its purpose is to provide a technology that optimizes the update frequency of the battery characteristic map of each battery pack in an operation in which each battery pack downloads and uses a battery characteristic map generated by collecting battery data from multiple battery packs.

[0007] In order to solve the above problems, a battery analysis system according to one aspect of the present disclosure includes: a battery data acquisition unit that acquires, via a network, battery data including a degradation index value of a secondary battery included in a battery pack; a map generation unit that generates a battery characteristic map including the degradation index value on a condition axis based on battery data of secondary batteries of the same type acquired from a plurality of battery packs; a map evaluation value calculation unit that calculates an evaluation value indicating a degree of completeness of the battery characteristic map; and a map transmission unit that transmits the battery characteristic map to the battery pack via the network. When a difference between an evaluation value of the battery characteristic map of a version currently in use in a battery pack to which the battery characteristic map is to be transmitted and an evaluation value of the battery characteristic map of a latest version is equal to or less than a threshold, the map transmission unit skips transmission of the battery characteristic map of the latest version to the battery pack.

[0008] Any combination of the above components, and conversion of the expression of the present disclosure into an apparatus, system, method, computer program, etc., are also valid aspects of the present disclosure.

[0009] According to the present disclosure, in an operation in which each battery pack downloads and uses a battery characteristic map generated by collecting battery data from multiple battery packs, the update frequency of the battery characteristic map for each battery pack can be optimized.

[0010] 1 is a diagram for explaining a battery analysis system according to an embodiment. FIG. 2 is a diagram illustrating an example of the configuration of a battery pack according to an embodiment. FIG. 3 is a diagram illustrating an example of the configuration of a control unit and a storage unit in the battery pack of FIG. 2. FIG. 4 is a diagram illustrating a specific image of an FCC estimation method. FIG. 5 is a diagram illustrating an example of the configuration of a battery analysis system according to an embodiment. FIG. 6 is a diagram illustrating a schematic data structure of an internal resistance map stored in an internal resistance map storage unit. FIG. 7 is a diagram illustrating a specific example of an evaluation value of an internal resistance map stored in a map evaluation value storage unit. FIG. 8 is a flowchart illustrating a flow of an internal resistance map generation process by a battery analysis system according to an embodiment. FIG. 9 is a flowchart illustrating a flow of an example 1 of an update process of an internal resistance map used by a battery pack by a battery analysis system according to an embodiment. FIG. 10 is a flowchart illustrating a flow of an example 2 of an update process of an internal resistance map used by a battery pack by a battery analysis system according to an embodiment.

[0011] FIG. 1 is a diagram illustrating a battery analysis system 10 according to an embodiment. The battery analysis system 10 according to the embodiment is a system for analyzing a battery pack 30 mounted on a battery-equipped device (assumed to be an electric bicycle 1 in this embodiment). The battery analysis system 10 may be constructed, for example, on an in-house server installed in the in-house facility or data center of a provider that provides analysis services for the battery pack 30. The battery analysis system 10 may also be constructed on a cloud server used based on a cloud service. The battery analysis system 10 may also be constructed on multiple servers distributed across multiple locations (data centers, in-house facilities). The multiple servers (e.g., a control server and an analysis server) may be a combination of multiple in-house servers, a combination of multiple cloud servers, or a combination of an in-house server and a cloud server.

[0012] The electric bicycle 1 is equipped with a detachable, portable, and replaceable battery pack 30. The battery pack 30 is charged while attached to a charging slot of a charger (not shown). The charged battery pack 30 is removed from the charging slot by the user and attached to the attachment slot of the electric bicycle 1.

[0013] The battery pack 30 and the mobile terminal device 20 (hereinafter, assumed to be a smartphone) carried by the user are connected via short-range wireless communication. Bluetooth (registered trademark), Wi-Fi (registered trademark), infrared communication, etc. can be used as short-range wireless communication. In the following, in this embodiment, it is assumed that BLE (Bluetooth Low Energy) is used as short-range wireless communication. BLE is an extended standard of Bluetooth and is a low-power short-range wireless communication standard using the 2.4 GHz band.

[0014] The mobile terminal device 20 can access the network 2 to which the battery analysis system 10 is connected. The mobile terminal device 20 can access the network 2 via a mobile phone network (4G / 5G) or Wi-Fi.

[0015] Network 2 is a general term for communication paths such as the Internet, dedicated lines, and VPNs (Virtual Private Networks), and the communication media and protocols are not important. Examples of communication media that can be used include wired LANs, wireless LANs, mobile phone networks, optical fiber networks, ADSL networks, and CATV networks. Examples of communication protocols that can be used include TCP (Transmission Control Protocol) / IP (Internet Protocol), UDP (User Datagram Protocol) / IP, and Ethernet (registered trademark).

[0016] 2 is a diagram showing an example of the configuration of a battery pack 30 according to an embodiment. The battery pack 30 includes a battery pack 31 and a battery management device 32. The battery pack 31 includes multiple cells E1-En connected in series. The number of cells connected in series is determined by the load specifications. The main loads of the electric bicycle 1 are the motor and the inverter.

[0017] The cells can be lithium-ion battery cells, nickel-metal hydride battery cells, lead battery cells, etc. In the following description, we will assume an example in which lithium-ion battery cells (nominal voltage: 3.6-3.7 V) are used. Note that in each series stage of cells, multiple cells may be connected in parallel to increase capacity.

[0018] A switch SW1 for switching between electrical continuity with the load or charger is inserted in the power line connecting the battery pack 31 and the load or charger. A semiconductor switch or a relay can be used as the switch SW1.

[0019] The battery management device 32 includes a measurement unit 33, a control unit 34, a storage unit 35, a wireless communication unit 36, and an antenna 36a. The measurement unit 33 is configured with an AFE (Analog Front End) IC or an ASIC (Application Specific Integrated Circuit). The control unit 34 is configured with a microcontroller. The storage unit 35 is a non-volatile storage unit, and can use an EEPROM (Electrically Erasable Programmable Read Only Memory) or a NAND flash memory.

[0020] The measurement unit 33 is connected to each node of the multiple cells E1-En connected in series by multiple voltage measurement lines, and measures the voltage of each cell E1-En by measuring the voltage between each two adjacent voltage measurement lines.

[0021] The measurement unit 33 includes a multiplexer and an A / D converter. The multiplexer outputs the voltages of the multiple cells E1-En to the A / D converter in a predetermined order. The A / D converter converts the analog voltages input from the multiplexer into digital values. The measurement unit 33 transmits the voltage values ​​of the cells E1-En, converted into digital values, to the control unit 34 via a serial communication interface.

[0022] The measurement unit 33 measures the current flowing through the battery pack 31. A shunt resistor Rs is connected to a power line connecting the battery pack 31 to a load or a charger. A differential amplifier (not shown) amplifies the voltage across the shunt resistor Rs and outputs it to an A / D converter in the measurement unit 33. The A / D converter converts the analog voltage indicating the current flowing through the battery pack 31, which is input from the differential amplifier, into a digital value. The measurement unit 33 transmits the current value converted into a digital value to the control unit 34 via a serial communication interface.

[0023] A temperature sensor T1 (e.g., a thermistor) is installed on the surface of the battery pack 31. A divided voltage between the temperature sensor T1 and a voltage dividing resistor (not shown) is input to a measurement unit 33. An A / D converter in the measurement unit 33 converts the input analog voltage indicating the temperature into a digital value. The measurement unit 33 transmits the converted digital temperature value to the control unit 34 via a serial communication interface.

[0024] Fig. 3 shows an example of the configuration of the control unit 34 and storage unit 35 in the battery pack 30 of Fig. 2. The control unit 34 includes a battery data acquisition and transmission unit 341, an SOC estimation unit 342, an SOH (State Of Health) estimation unit 343, and a map request and acquisition unit 344. The storage unit 35 includes a battery data storage unit 351, an internal resistance map storage unit 352, and an SOC-OCV curve storage unit 353.

[0025] The battery data acquisition and transmission unit 341 stores the voltage value of each cell E1-En, the value of the current flowing through the battery pack 31, and the temperature value of the battery pack 31 received from the measurement unit 33 in the battery data storage unit 351 at a predetermined storage period (for example, every one minute). Note that the cell voltages may be stored as the voltage values ​​of all cells E1-En, or only the maximum cell voltage and the minimum cell voltage.

[0026] The battery protection unit (not shown) detects overcharging, over-discharging, overcurrent, high temperature abnormality, or low temperature abnormality based on the voltage values ​​of each cell E1-En, the current value flowing through the battery pack 31, and the temperature value of the battery pack 31 received from the measurement unit 33, and sends a signal to turn off switch SW1 to the measurement unit 33 to turn off switch SW1.

[0027] The SOC estimation unit 342 estimates the SOC of the cell based on an equivalent circuit model of the cell and the OCV (Open Circuit Voltage) method. For example, the SOC estimation unit 342 uses a simple equivalent circuit model shown in the following (Equation 1) to estimate the OCV of the cell based on the cell voltage (terminal voltage V(t)) and current I(t) at time t: OCV = V(t) - I(t) * Ri (Equation 1), where Ri is the internal resistance (ohmic resistance component).

[0028] The simple equivalent circuit model defined by the above (Equation 1) includes only a DC resistance that describes the ohmic resistance component, but a more detailed equivalent circuit model includes one or more stages of RC parallel circuits that describe non-ohmic resistance components (transient polarization characteristics) in addition to the DC resistance.

[0029] The SOC estimation unit 342 estimates the SOC from the estimated OCV by referring to the SOC-OCV curve stored in the SOC-OCV curve storage unit 353. The SOC-OCV curve of the cell is created in advance based on characteristics tests conducted by the battery manufacturer and is stored in the SOC-OCV curve storage unit 353 at the time of shipment. The SOC-OCV curve may be registered in the ROM in the control unit 34. The SOC estimation unit 342 stores the estimated SOC of the cell in the battery data storage unit 351.

[0030] The SOH estimation unit 343 estimates the SOH of the cell using the two-point OCV method. The SOH estimation unit 343 calculates the SOC difference (ΔSOC) between the SOC in the first rest state and the SOC in the second rest state based on the voltage of the cell in the first rest state, the voltage of the cell in the second rest state, and the SOC-OCV curve of the cell. The SOH estimation unit 343 calculates the current integrated value (= charge / discharge capacity) Q for the period between the first rest state and the second rest state based on the current value included in the battery data. The SOH estimation unit 343 calculates the current FCC (Full Charge Capacity) of the cell based on the current integrated value Q and ΔSOC. The SOH estimation unit 343 calculates the SOH based on the current FCC and initial FCC of the cell.

[0031] 4 is a diagram showing a specific image of the FCC estimation method. The SOH estimation unit 343 identifies two voltages, the first rest state and the second rest state, and sets these as the OCVs at two points. The SOH estimation unit 343 references the SOC-OCV curve to identify SOC1 and SOC2 corresponding to OCV1 and OCV2, respectively, and calculates ΔSOC between SOC1 and SOC2 and the current integrated value Q.

[0032] The SOH estimation unit 343 calculates the following (Equation 2) to estimate the FCC: FCC=Q / ΔSOC (Equation 2)

[0033] The SOH is defined as the ratio of the current FCC to the initial FCC, and the lower the value (closer to 0%), the more advanced the deterioration. The SOH estimation unit 343 estimates the SOH by calculating the following (Equation 3): SOH = current FCC / initial FCC × 100 (Equation 3)

[0034] The SOC estimation unit 342 stores the estimated SOH of the cell in the battery data storage unit 351 .

[0035] The map request / acquisition unit 344 transmits a request to acquire an internal resistance map to the battery analysis system 10, receives the internal resistance map from the battery analysis system 10, and stores the received internal resistance map in the internal resistance map storage unit 352. The detailed processing contents of the map request / acquisition unit 344 will be described later.

[0036] Returning to Fig. 2, the wireless communication unit 36 ​​performs signal processing for short-range wireless communication. The wireless communication unit 36 ​​pairs with the mobile terminal device 20 and transmits a request to acquire battery data or an internal resistance map stored in the storage unit 35 via short-range wireless communication. In this embodiment, the wireless communication unit 36 ​​is configured by a BLE module, and the antenna 36a is configured by a chip antenna or a pattern antenna built into the BLE module.

[0037] Mobile terminal device 20 is a terminal device carried by the user of electric bicycle 1. The user downloads an application program for managing electric bicycle 1 (hereinafter referred to as a bicycle app) from a distribution server to mobile terminal device 20 and installs it on mobile terminal device 20. The bicycle app is uploaded to the distribution server in advance, and the distribution server provides the bicycle app it manages to mobile terminal device 20 that accesses it via network 2.

[0038] The bicycle app works in conjunction with a map app installed on the mobile terminal device 20 and a GPS (Global Positioning System) sensor to display the current location of the electric bicycle 1 on the display unit of the mobile terminal device 20. The bicycle app can also estimate the speed, distance traveled, calories burned, etc. based on the movement trajectory of the position of the electric bicycle 1 and display these on the display unit of the mobile terminal device 20.

[0039] When the user of the electric bicycle 1 launches the bicycle app on the portable terminal device 20 while the Bluetooth of the portable terminal device 20 is on, a connection is established between the short-range wireless communication unit of the portable terminal device 20 and the wireless communication unit 36 ​​of the battery pack 30.

[0040] When a connection with the mobile terminal device 20 is established, the battery data acquisition and transmission unit 341 of the battery pack 30 transmits the battery data stored in the battery data holding unit 351 to the mobile terminal device 20 via the wireless communication unit 36. Specifically, the battery data acquisition and transmission unit 341 transmits time-series data of the voltage, current, temperature, SOC, and SOH of each cell E1-En, or time-series data of the voltage, current, temperature, SOC, and SOH of the maximum voltage cell and the minimum voltage cell, as battery data.

[0041] The mobile terminal device 20 transfers the battery data received from the short-range wireless communication unit to the battery analysis system 10 via the network 2. The mobile terminal device 20 can access the network 2 via a mobile phone network (4G / 5G) or Wi-Fi.

[0042] After transmitting the battery data to the battery analysis system 10 via the mobile terminal device 20 , the battery data acquisition and transmission unit 341 of the battery pack 30 erases the transmitted battery data from the battery data storage unit 351 .

[0043] With the battery pack 30 and the portable terminal device 20 connected via short-range wireless communication, the map request / acquisition unit 344 transmits a request to acquire the latest version of the internal resistance map to the battery analysis system 10 via the portable terminal device 20. The map request / acquisition unit 344 includes in the request to acquire the internal resistance map the version of the internal resistance map currently stored in the internal resistance map storage unit 352 and the maximum SOH among the SOHs of the cells E1-En.

[0044] The map request / acquisition unit 344 transmits a request for the current internal resistance map when a certain period of time (e.g., one week) has elapsed since the previous request for the internal resistance map was transmitted. If the battery pack 30 is not activated or the battery pack 30 and the mobile terminal device 20 are not wirelessly connected when the certain period of time has elapsed since the previous request for the internal resistance map was transmitted, the map request / acquisition unit 344 transmits a request for the current internal resistance map when the battery pack 30 is next activated or the battery pack 30 and the mobile terminal device 20 are next wirelessly connected after the certain period of time has elapsed.

[0045] 5 is a diagram showing an example of the configuration of a battery analysis system 10 according to an embodiment. The battery analysis system 10 includes a control unit 11, a storage unit 12, and a communication unit 13. The communication unit 13 is an external communication interface (e.g., a network interface card (NIC)) for connecting to the network 2 via a wired or wireless connection.

[0046] The control unit 11 includes a battery data acquisition unit 111, an internal resistance calculation unit 112, a map generation unit 113, a map evaluation value calculation unit 114, and a map transmission unit 115. The functions of the control unit 11 can be realized by a combination of hardware resources and software resources, or by hardware resources alone. Examples of hardware resources that can be used include a CPU, ROM, RAM, GPU (Graphics Processing Unit), NPU (Neural Network Processing Unit), ASIC, FPGA (Field Programmable Gate Array), and other LSIs. Examples of software resources that can be used include an operating system, application programs, and the like.

[0047] The storage unit 12 includes a non-volatile recording medium such as a hard disk drive (HDD) or a solid state drive (SSD), and stores various data. The storage unit 12 includes a battery data storage unit 121, an internal resistance data storage unit 122, an internal resistance map storage unit 123, and a map evaluation value storage unit 124.

[0048] The battery data acquisition unit 111 acquires the battery data of each battery pack 30 from each battery pack 30 via the network 2 using the mobile terminal device 20 as a relay. The battery data acquisition unit 111 stores the acquired battery data in the battery data holding unit 121.

[0049] The internal resistance calculation unit 112 calculates the internal resistance of each cell E1-En based on time series data of the voltage and current of each cell E1-En of each battery pack 30. As shown in the following (Equation 4), the internal resistance calculation unit 112 calculates the internal resistance Ri based on the current I(t0) and voltage V(t0) at the end of discharge t0, and the voltage V(t1) after a predetermined time (for example, 1 second) has elapsed since the end of discharge t0. Ri=(V(t1)-V(t0)) / I(t0) (Equation 4)

[0050] The internal resistance calculation unit 112 stores the calculated internal resistance Ri for each battery type in the internal resistance data storage unit 122. The internal resistance data for each battery type is classified and stored for each combination of multiple conditions (in this embodiment, SOH, SOC, temperature, and current).

[0051] The internal resistance Ri of each cell E1-En of each battery pack 30 may be calculated by the control unit 34 of each battery pack 30 and may be included in the battery data transmitted from the battery pack 30 to the battery analysis system 10. In this case, the internal resistance calculation unit is omitted from the battery analysis system 10 and provided in the control unit 34 of the battery pack 30.

[0052] The map generation unit 113 periodically (e.g., weekly) reads the internal resistance Ri from the internal resistance data storage unit 122 and plots the internal resistance Ri of cells of the same type in a space described by four condition axes: SOH, SOC, temperature, and current, to generate an internal resistance map. For the internal resistance Ri for each condition stored in the internal resistance data storage unit 122, for which multiple internal resistances Ri are stored, the map generation unit 113 calculates statistical values ​​(e.g., averages or medians) of the multiple internal resistances Ri and plots the statistical values ​​of the internal resistance Ri for that condition in the space. For internal resistance Ri for which no data is stored, the map generation unit 113 plots 0 as the data for that condition. The map generation unit 113 assigns a version to the generated internal resistance map and saves it in the internal resistance map storage unit 123.

[0053] 6 is a diagram showing a schematic diagram of the data structure of the internal resistance map stored in the internal resistance map storage unit 123. The internal resistance map is described in a four-dimensional space having four condition axes: SOH, SOC, temperature, and current. For the SOH, the SOH at the same time (t0) as the current I(t0) and voltage (t0) included in the battery data used to calculate the internal resistance Ri is used. The upper limit of the SOH axis is defined as 100%, and the lower limit is defined as 0%. The increments of the SOH axis are set to, for example, 1%, 5%, or 10%.

[0054] The SOC is calculated based on the current I(t0) and voltage (t0) included in the battery data used to calculate the internal resistance Ri. The upper limit of the SOC axis is defined as 100% and the lower limit is defined as 0%. The increments of the SOC axis are set to, for example, 1%, 5%, or 10%.

[0055] The temperature is the temperature at the same time (t0) as the current I(t0) and voltage (t0) included in the battery data used to calculate the internal resistance Ri. The upper limit of the temperature axis is defined as 60°C, for example, and the lower limit is defined as -10°C. The increments of the temperature axis are set to 1°C or 5°C, for example.

[0056] The current I(t0) included in the battery data used to calculate the internal resistance Ri is used as the current. For example, the charge current may be defined as positive and the discharge current as negative, with the upper limit of the current axis defined as the rated charge current of the target cell and the lower limit defined as the rated discharge current. The temperature axis may be set to an increment of 1 A, for example. The current may also be defined as a C rate.

[0057] Of the four condition axes, the SOH axis is a required condition axis. The SOC axis, temperature axis, and current axis are optional condition axes; for example, the current axis may be omitted. In this case, the internal resistance map is described in a three-dimensional space having three condition axes: SOH, SOC, and temperature.

[0058] The map evaluation value calculation unit 114 calculates an evaluation value indicating the degree of completeness of the internal resistance map generated by the map generation unit 113. In this embodiment, the degree of completeness of the internal resistance map is defined by the degree of spread of the distribution of data already plotted in space (hereinafter referred to as clarity rate) and the rate of change between the latest version and the previous version. The map evaluation value calculation unit 114 calculates the evaluation value of the internal resistance map for each SOH.

[0059] The map evaluation value calculation unit 114 calculates the evaluation value of the internal resistance map using, for example, the following (Equation 5). Note that instead of a simple average of the clarity rate and the change rate, a weighted average may be used: Evaluation value = (clarity rate + change rate) / 2 (Equation 5)

[0060] The map evaluation value calculation unit 114 calculates the clarity rate using, for example, the following (Equation 6). Clarity rate=(mSOC+mTemp+mCurrent) / 3 (Equation 6) mSOC=(maxSOC-minSOC) / (axismaxSOC-axisminSOC) mTemp=(maxTemp-minTemp) / (axismaxTemp-axisminTemp) mCurrent=(maxC-minC) / (axismaxC-axisminC) axismaxSOC: upper limit value of SOC axis (e.g., 100%) axisminSOC: lower limit value of SOC axis (e.g., 0%) maxSOC: maximum SOC value of data (internal resistance Ri) plotted in space minSOC: minimum SOC value of data plotted in space axismaxTemp: Upper limit of the temperature axis (e.g., 60°C) axisminTemp: Lower limit of the temperature axis (e.g., -10°C) maxTemp: Maximum temperature value of the data plotted in the space minTemp: Minimum temperature value of the data plotted in the space axismaxC: Upper limit of the current axis (e.g., rated charge current) axisminC: Lower limit of the current axis (e.g., rated discharge current) maxC: Maximum current value of the data plotted in the space minC: Minimum current value of the data plotted in the space

[0061] The clarity factor when no current axis is provided is defined by the following formula (7): Clarity factor=(mSOC+mTemp) / 2 (7)

[0062] The map evaluation value calculation unit 114 calculates the rate of change of the internal resistance map using, for example, the following (Equation 8). The map evaluation value calculation unit 114 calculates the rate of change of data for each condition in the internal resistance map of the latest version and the previous version, and calculates the rate of change of the internal resistance map by accumulating the absolute values ​​of the rate of change of all conditions. Rate of change = Σ|(map_new - map_old) / map_old| ... (Equation 8)

[0063] In the above (Equation 6) or (Equation 7), the closer the clarity rate value is to 1, the wider the distribution of the plotted data in space, indicating a high degree of completeness of the internal resistance map. In the above (Equation 8), the larger the value of the change rate, the greater the change from the previous version and the greater the need to update to the latest version. In this way, the higher the evaluation value shown in the above (Equation 5), the greater the degree of completeness of the internal resistance map and the greater the need to update.

[0064] The map evaluation value calculation unit 114 stores the evaluation value of the internal resistance map calculated for each SOH in the map evaluation value holding unit 124 .

[0065] 7 is a diagram showing a specific example of the evaluation value of the internal resistance map stored in the map evaluation value storage unit 124. The evaluation values ​​of the internal resistance map are classified and stored by version, and the evaluation values ​​of the internal resistance map of each version are stored for each SOH classification. While FIG. 7 shows an example in which the SOH is classified in increments of 10%, it may also be classified in increments of 1% or 5%.

[0066] The map transmission unit 115 transmits the internal resistance map to the battery pack 30 via the network 2. The map transmission unit 115 identifies the version of the internal resistance map currently being used by the battery pack 30 that transmitted the internal resistance map acquisition request (hereinafter referred to as the "current version") by referring to additional information in the acquisition request. The map transmission unit 115 reads, from the internal resistance map holding unit 123, the evaluation values ​​of the internal resistance map of all SOH categories of the current version and the evaluation values ​​of the internal resistance map of all SOH categories of the latest version.

[0067] The map transmission unit 115 calculates the difference between the evaluation value of the currently used version of the internal resistance map that has been read and the evaluation value of the latest version of the internal resistance map for each SOH category. The map transmission unit 115 calculates a statistical value (e.g., an average or median) of the evaluation value for each SOH category to calculate the evaluation value difference of the internal resistance map. The map transmission unit 115 compares the evaluation value difference with a threshold value. The threshold value is set by the designer based on the designer's knowledge and the results of experiments and simulations.

[0068] If the evaluation value difference is greater than the threshold, the map transmission unit 115 reads the latest version of the internal resistance map from the internal resistance map storage unit 123 and transmits the read internal resistance map to the battery pack 30 that issued the acquisition request. If the evaluation value difference is equal to or less than the threshold, the map transmission unit 115 does not transmit the latest version of the internal resistance map to the battery pack 30 that issued the acquisition request.

[0069] When the SOH (hereinafter referred to as pack SOH) is included in the additional information of the internal resistance map acquisition request, the map transmission unit 115 reads out the evaluation values ​​of the internal resistance map of SOH divisions around the pack SOH of the currently used version and the evaluation values ​​of the internal resistance map of SOH divisions around the pack SOH of the latest version from the internal resistance map holding unit 123. For example, the map transmission unit 115 reads out the evaluation values ​​of the internal resistance map of SOH divisions included in the range of +5% to -10% with the pack SOH acquired from the battery pack 30 that has made the acquisition request as the center.

[0070] In addition, in the case of specifications for updating only a partial internal resistance map in the range in the direction of deterioration progression, the map transmission unit 115 reads, for example, the evaluation value of the internal resistance map for the SOH category included in the range of -10% starting from the pack SOH value.

[0071] The map transmission unit 115 calculates the difference between the evaluation value of the read internal resistance map of the currently used version and the evaluation value of the latest version of the internal resistance map for each SOH category. The map transmission unit 115 calculates a statistical value of the evaluation values ​​for each SOH category to calculate the evaluation value difference of the internal resistance map. The map transmission unit 115 compares the evaluation value difference with a threshold. If the evaluation value difference is greater than the threshold, the map transmission unit 115 reads a partial internal resistance map of the SOH category surrounding the latest version of the pack SOH from the internal resistance map holding unit 123 and transmits the read partial internal resistance map to the battery pack 30 that issued the acquisition request. If the evaluation value difference is equal to or less than the threshold, the map transmission unit 115 does not transmit the latest version of the partial internal resistance map to the battery pack 30 that issued the acquisition request.

[0072] In another example where the pack SOH is included in the additional information of the internal resistance map acquisition request, the map transmission unit 115 reads out the evaluation values ​​of the internal resistance map for the SOH divisions after the pack SOH and the evaluation values ​​of the internal resistance map for the SOH divisions after the pack SOH in the latest version in descending order of the currently used version from the internal resistance map storage unit 123. Specifically, the map transmission unit 115 reads out the evaluation values ​​of the internal resistance map for the SOH divisions included in the range of 0% from the pack SOH value.

[0073] The map transmission unit 115 calculates the difference between the evaluation value of the read internal resistance map of the currently used version and the evaluation value of the latest version of the internal resistance map for each SOH category. The map transmission unit 115 calculates a statistical value of the evaluation values ​​for each SOH category to calculate the evaluation value difference of the internal resistance map. The map transmission unit 115 compares the evaluation value difference with a threshold. If the evaluation value difference is greater than the threshold, the map transmission unit 115 reads partial internal resistance maps from the pack SOH onwards in descending order of the latest version from the internal resistance map holding unit 123 and transmits the read partial internal resistance maps to the battery pack 30 that issued the acquisition request. If the evaluation value difference is equal to or less than the threshold, the map transmission unit 115 does not transmit the partial internal resistance map of the latest version to the battery pack 30 that issued the acquisition request.

[0074] 8 is a flowchart showing the flow of the process of generating an internal resistance map by the battery analysis system 10 according to the embodiment. The battery data acquisition unit 111 acquires battery data of each battery pack 30 from each battery pack 30 via the network 2 (S10).

[0075] The internal resistance calculation unit 112 identifies the current data at the end of charging and discharging and the voltage data after the end of charging and discharging based on the time-series data of the voltage and current of each cell E1-En included in the battery data of each battery pack 30, and calculates the internal resistance of each cell E1-En from the voltage behavior after the end of charging and discharging (S11). The internal resistance calculation unit 112 classifies the calculated internal resistances according to multiple conditions including SOH, and stores them in the internal resistance data storage unit 122 (S12).

[0076] The map generator 113 determines whether one week has passed since the previous generation of the internal resistance map (S13). If one week has not passed (N in S13), the process proceeds to step S10, where the collection of battery data and the calculation and storage of the internal resistance are continued.

[0077] If one week has passed since the previous generation of the internal resistance map (Y in S13), the map generation unit 113 reads the internal resistances classified by multiple conditions, including SOH, from the internal resistance data storage unit 122, and performs statistical processing on the read internal resistances for each condition to calculate statistical values ​​of the internal resistance for each condition. The map generation unit 113 plots the statistical values ​​of the internal resistance for each condition in a space described by multiple condition axes to generate an internal resistance map (S14). The map generation unit 113 assigns a version to the generated internal resistance map and stores it in the internal resistance map storage unit 123 (S15).

[0078] The map evaluation value calculation unit 114 calculates an evaluation value of the internal resistance map generated by the map generation unit 113 for each SOH (S16), and stores the calculated evaluation value of the internal resistance map in the map evaluation value storage unit 124 (S17). The processing of steps S10 to S17 described above is executed continuously. After the electric bicycle 1 equipped with the battery pack 30 is sold, as time passes, a large amount of battery data from battery packs 30 of the same type is collected, and the internal resistance map is gradually enriched.

[0079] 9 is a flowchart showing a flow of an example 1 of a process for updating an internal resistance map used by a battery pack 30, performed by the battery analysis system 10 according to an embodiment. The map transmission unit 115 receives a request to acquire an internal resistance map (including the version currently in use) from the battery pack 30 (S20). The map transmission unit 115 reads out the evaluation values ​​of the internal resistance maps of all SOH sections of the version currently in use and the latest version from the map evaluation value holding unit 124 (S21).

[0080] The map transmission unit 115 calculates the difference between the evaluation value of the internal resistance map of the currently used version that has been read and the evaluation value of the latest version of the internal resistance map for each SOH category. The map transmission unit 115 calculates the statistical value of the evaluation value for each SOH category and calculates the evaluation value difference of the internal resistance map (S22).

[0081] The map transmission unit 115 compares the evaluation value difference with a threshold (S23). If the evaluation value difference is greater than the threshold (Y in S23), the map transmission unit 115 reads the latest version of the internal resistance map from the internal resistance map storage unit 123 and transmits the read internal resistance map to the battery pack 30 that requested the acquisition (S24). If the evaluation value difference is equal to or less than the threshold (N in S23), the processing of step S24 is skipped.

[0082] 10 is a flowchart showing a flow of a second example of a process for updating the internal resistance map used by the battery pack 30, performed by the battery analysis system 10 according to the embodiment. The map transmission unit 115 receives an internal resistance map acquisition request (including the version currently in use and the pack SOH) from the battery pack 30 (S30). The map transmission unit 115 reads out, from the map evaluation value holding unit 124, the version currently in use included in the internal resistance map acquisition request and the evaluation values ​​of the internal resistance maps for the SOH classifications subsequent to the latest version of the pack SOH (in descending order) (S31).

[0083] The map transmission unit 115 calculates the difference between the evaluation value of the internal resistance map of the currently used version that has been read and the evaluation value of the latest version of the internal resistance map for each SOH category. The map transmission unit 115 calculates the statistical value of the evaluation value for each SOH category and calculates the evaluation value difference of the internal resistance map (S32).

[0084] The map transmission unit 115 compares the evaluation value difference with a threshold (S33). If the evaluation value difference is greater than the threshold (Y in S33), the map transmission unit 115 reads the partial internal resistance maps (in descending order) from the latest version of pack SOH onwards from the internal resistance map storage unit 123 and transmits the read partial internal resistance maps to the battery pack 30 that issued the acquisition request (S34). If the evaluation value difference is equal to or less than the threshold (N in S33), the processing of step S34 is skipped.

[0085] 8 to 10 have described an example in which the evaluation value of the internal resistance map is calculated in advance and stored in the map evaluation value storage unit 124. In this regard, a sequence may be adopted in which the evaluation value of the internal resistance map in use and the evaluation value of the internal resistance map of the latest version are calculated at the timing when an acquisition request for the internal resistance map is received from each battery pack 30.

[0086] When the map request / acquisition unit 344 of the battery pack 30 receives the latest version of the internal resistance map from the battery analysis system 10 , it overwrites and saves the received latest version of the internal resistance map in the internal resistance map storage unit 352 .

[0087] When estimating the OCV of a specific cell during charging / discharging of the battery pack 31, the SOC estimation unit 342 identifies the SOH, SOC, temperature, and current of the cell at that time, and references the internal resistance map stored in the internal resistance map storage unit 352 to obtain an internal resistance Ri that matches the SOH, SOC, temperature, and current conditions. The SOC estimation unit 342 applies the obtained internal resistance Ri to the equivalent circuit model shown in the above (Equation 1) to estimate the OCV of the cell. The SOC estimation unit 342 references the SOC-OCV curve stored in the SOC-OCV curve storage unit 353 to estimate the SOC from the estimated OCV.

[0088] As described above, according to this embodiment, in an operation in which each battery pack 30 downloads and uses an internal resistance map generated by the battery analysis system 10, the update frequency of the internal resistance map in each battery pack 30 can be optimized by downloading the internal resistance map only when an update of the internal resistance map has been made that has a large effect on control within the battery pack 30. In other words, when only an update that has a small effect on control within the battery pack 30 has been made, downloading of the latest version of the internal resistance map can be skipped, thereby reducing the impact on control and reducing the amount of communication.

[0089] Considering that a large number of battery packs 30 will be put into use at the same time following the release of a new product, the collection status of data in the descending direction of SOH changes daily, and it is thought that this will have a significant impact on control. In such cases, it is desirable to use the latest version of the internal resistance map in accordance with the changing status. If the collected battery characteristics change rapidly, it is desirable to apply the latest version of the internal resistance map as soon as possible.

[0090] Furthermore, when downloading and updating the internal resistance map, the amount of communication can be further reduced by downloading only the internal resistance map of the SOH section after the pack SOH in descending order. Furthermore, when downloading and updating the internal resistance map, the amount of communication can be further reduced by downloading only the internal resistance map of the SOH section around the pack SOH. The area around the pack SOH may be defined only in descending order, or in both descending and ascending orders. The SOH basically progresses in descending order, but there is a possibility that it may return to ascending order due to an error in the SOH estimation process.

[0091] The narrower the range around the pack SOH, the less communication traffic the internal resistance map downloads per update. In usage situations where the battery pack 30 is frequently started up, defining a narrower range around the pack SOH will not cause any problems. The map transmission unit 115 of the battery analysis system 10 may calculate the frequency of requests to acquire the internal resistance map for each battery pack 30 and adjust the range around the pack SOH according to the calculated frequency. The frequency of requests to acquire the internal resistance map from the battery pack 30 depends on the startup frequency of the battery pack 30, which in turn depends on the frequency of use of the electric bicycle 1. The map transmission unit 115 determines that the battery pack 30 is started up less frequently the less frequently the battery pack 30 requests to acquire the internal resistance map, and sets a wider range around the pack SOH.

[0092] Furthermore, when evaluating the completeness of the internal resistance map, by taking into account the degree of spread of the data distribution in addition to the rate of change from the previous version, it is possible to determine whether to update the internal resistance map while also taking into account its practical value. When the degree of spread of the data distribution in space is wide, even if there is no data in the internal resistance map that exactly matches the SOH, SOC, temperature, and current conditions, it is easy to extract data with relatively similar conditions. Furthermore, by using data from multiple adjacent plots with similar conditions to interpolate the data with matching conditions, it is possible to predict the data with matching conditions with high accuracy.

[0093] The present disclosure has been described above based on the embodiments. The embodiments are merely examples, and it will be understood by those skilled in the art that various modifications are possible in the combination of the respective components and processing steps, and that such modifications are also within the scope of the present disclosure.

[0094] In the above-described embodiment, an example has been described in which the SOH is used as a degradation index value indicating the degradation state of a cell. In this regard, the total charge amount, total discharge amount, or elapsed time since the start of use of the cell may be used as the degradation index value of the cell. A value combining the total charge amount or total discharge amount and elapsed time may also be used. The total charge amount and total discharge amount correlate with cycle degradation, and elapsed time correlates with storage degradation. When these degradation index values ​​are used, there is no need to calculate the SOH, simplifying control within the battery pack 30.

[0095] In the above-described embodiment, an example has been described in which the battery analysis system 10 collects battery data from a plurality of battery packs 30 and generates an internal resistance map that is commonly used by the plurality of battery packs 30. In this regard, the battery analysis system 10 may collect battery data from a plurality of battery packs 30 and generate another battery characteristic map that is commonly used by the plurality of battery packs 30. For example, an SOC-OCV curve map may be generated.

[0096] For example, an SOC-OCV curve generator (not shown) identifies the voltage (OCV) and SOC during a rest period based on time-series battery data for each cell E1-En of each battery pack 30, and stores the SOC-OCV values ​​for each battery type in an SOC-OCV value storage unit (not shown). The map generator 113 periodically (e.g., weekly) reads the SOC-OCV values ​​from the SOC-OCV value storage unit and plots the SOC-OCV values ​​of cells of the same type in a space described by three condition axes: SOC (essential condition), SOH, and temperature, to generate an SOC-OCV curve map. Note that internal resistance may also be added to the condition axes. The method for calculating the evaluation value of the SOC-OCV curve map and the method for determining whether to transmit the latest version can be processed in the same manner as the method for calculating the evaluation value of the internal resistance map and the method for determining whether to transmit the latest version.

[0097] In the above-described embodiment, the electric bicycle 1 is assumed as the device to which the battery pack 30 is mounted. In this regard, the device to which the battery pack 30 is mounted may also be an electric motorcycle, an electric kick scooter, a micro EV, a multicopter (drone), an electric ship, an electric boat, a robot vacuum cleaner, or the like.

[0098] The embodiment may be specified by the following items.

[0099] [Item 1] A battery analysis system (10) comprising: a battery data acquisition unit (111) that acquires, via a network (2), battery data including a deterioration index value of secondary batteries (E1-En) included in a battery pack (30); a map generation unit (113) that generates a battery characteristic map including the deterioration index value on a condition axis based on battery data of secondary batteries (E1-En) of the same type acquired from a plurality of battery packs (30); a map evaluation value calculation unit (114) that calculates an evaluation value indicating a degree of completeness of the battery characteristic map; and a map transmission unit (115) that transmits the battery characteristic map to the battery pack (30) via the network (2), wherein the map transmission unit (115) skips transmission of the latest version of the battery characteristic map to the battery pack (30) when a difference between an evaluation value of the battery characteristic map of a version currently being used in the battery pack (30) to which the battery characteristic map is to be transmitted and an evaluation value of the battery characteristic map of a latest version is equal to or less than a threshold value. This allows the frequency of updating the battery characteristic map downloaded from the battery analysis system (10) to the battery pack (30) to be optimized. [Item 2] The battery data acquisition unit (111) acquires time-series data of a deterioration index value, voltage, current, temperature, and SOC (State Of Charge) of the secondary batteries (E1-En) as the battery data, and the map generation unit (113) plots the internal resistances of the secondary batteries (E1-En) included in the battery pack (30) in a space described by a plurality of condition axes, including a condition axis for the deterioration index value and at least one condition axis for SOC, temperature, and current, to generate an internal resistance map as the battery characteristic map. This allows the frequency of updating the internal resistance map downloaded from the battery analysis system (10) to the battery pack (30) to be optimized.[Item 3] The battery analysis system (10) according to Item 1, wherein the map evaluation value calculation unit (114) calculates an evaluation value of the battery characteristic map for each category of the deterioration index value, and the map transmission unit (115) calculates a difference between an evaluation value of a partial battery characteristic map of a version currently being used in the battery pack (30) to which the battery characteristic map is to be transmitted, the evaluation value of the partial battery characteristic map of the latest version, on a condition axis of the deterioration index value, the evaluation value of the partial battery characteristic map of the latest version, and if the difference between the evaluation value of the partial battery characteristic map of the version currently being used in the battery pack (30) to which the battery characteristic map is to be transmitted and the evaluation value of the partial battery characteristic map of the latest version is greater than a threshold, the latest version of the partial battery characteristic map is transmitted to the battery pack (30), and if the difference is equal to or less than the threshold, the latest version of the partial battery characteristic map is not transmitted to the battery pack (30). This reduces the amount of communication required when downloading a battery characteristic map from the battery analysis system (10) to the battery pack (30). [Item 4] The battery analysis system (10) according to Item 1, wherein the map evaluation value calculation unit (114) calculates an evaluation value of the battery characteristic map for each category of the deterioration index value, and the map transmission unit (115) calculates a difference between an evaluation value of a partial battery characteristic map of a version currently being used in a battery pack (30) to which the battery characteristic map is to be transmitted, the evaluation value of the partial battery characteristic map being within a range of a deterioration progression direction from the deterioration index value of the battery pack (30) on a condition axis of the deterioration index value, and an evaluation value of the partial battery characteristic map of the latest version, and if the difference between the evaluation value of the partial battery characteristic map of the version currently being used in the battery pack (30) to which the battery characteristic map is to be transmitted and the evaluation value of the partial battery characteristic map of the latest version is greater than a threshold, the partial battery characteristic map of the latest version is transmitted to the battery pack (30), and if the difference is equal to or less than the threshold, the partial battery characteristic map of the latest version is not transmitted to the battery pack (30). This allows for a reduction in the amount of communication required when downloading a battery characteristic map from the battery analysis system (10) to the battery pack (30).[Item 5] The battery analysis system (10) according to Item 1, wherein the degradation index value is defined by the SOH (State Of Health) of the secondary batteries (E1-En). This allows the progression of degradation of the secondary batteries (E1-En) to be grasped with high accuracy on a capacity basis. [Item 6] The battery analysis system (10) according to Item 1, wherein the degradation index value is defined by the total charge amount, total discharge amount, or elapsed time since the start of use of the secondary batteries (E1-En). This allows the progression of degradation of the secondary batteries (E1-En) to be easily estimated. [Item 7] The battery analysis system (10) according to Item 1, wherein the map evaluation value calculation unit (114) increases the evaluation value of the latest version of the battery characteristic map the greater the change in data from the previous version of the battery characteristic map, and the wider the distribution of data plotted within the space of the latest version of the battery characteristic map. This allows the completeness of the battery characteristic map to be appropriately evaluated. [Item 8] A battery analysis method comprising the steps of: acquiring, via a network (2), battery data including a deterioration index value of secondary batteries (E1-En) included in a battery pack (30); generating a battery characteristic map including the deterioration index value on a condition axis based on the battery data of secondary batteries (E1-En) of the same type acquired from a plurality of battery packs (30); calculating an evaluation value indicating a degree of completeness of the battery characteristic map; and transmitting the battery characteristic map to the battery pack (30) via the network (2), wherein the step of transmitting the battery characteristic map skips transmission of the latest version of the battery characteristic map to the battery pack (30) if a difference between an evaluation value of the battery characteristic map of a version currently in use in the battery pack (30) to which the battery characteristic map is to be transmitted and an evaluation value of the battery characteristic map of a latest version is equal to or less than a threshold. This allows the frequency of updates of the battery characteristic map downloaded from the battery analysis system (10) to the battery pack (30) to be optimized.[Item 9] A battery analysis program that causes a computer to execute the following processes: acquiring, via a network (2), battery data including a deterioration index value of secondary batteries (E1-En) included in a battery pack (30); generating a battery characteristic map including the deterioration index value on a condition axis based on the battery data of secondary batteries (E1-En) of the same type acquired from a plurality of battery packs (30); calculating an evaluation value indicating a degree of completeness of the battery characteristic map; and transmitting the battery characteristic map to the battery pack (30) via the network (2), wherein the process of transmitting the battery characteristic map skips transmission of the latest version of the battery characteristic map to the battery pack (30) if a difference between an evaluation value of the battery characteristic map of a version currently in use in the battery pack (30) to which the battery characteristic map is to be transmitted and an evaluation value of the battery characteristic map of a latest version is equal to or less than a threshold value. This allows the frequency of updates of the battery characteristic map downloaded from the battery analysis system (10) to the battery pack (30) to be optimized.

[0100] The present disclosure can be used to generate a battery characteristic map of a battery pack.

[0101] REFERENCE SIGNS LIST 1 Electric bicycle, 2 Network, 20 Portable terminal device, 30 Battery pack, 31 Assembled battery, 32 Battery management device, 33 Measurement unit, 34 Control unit, 341 Battery data acquisition and transmission unit, 342 SOC estimation unit, 343 SOH estimation unit, 344 Map request and acquisition unit, 35 Memory unit, 351 Battery data storage unit, 352 Internal resistance map storage unit, 353 SOC-OCV curve storage unit, 36 Wireless communication unit, 36a Antenna, E1-En Cell, Rs Shunt resistor, T1 Temperature sensor, SW1 Switch, 10 Battery analysis system, 11 Control unit, 111 Battery data acquisition unit, 112 Internal resistance calculation unit, 113 Map generation unit, 114 Map evaluation value calculation unit, 115 Map transmission unit, 116 life expectancy prediction unit, 12 storage unit, 121 battery data storage unit, 122 internal resistance data storage unit, 123 internal resistance map storage unit, 124 map evaluation value storage unit, 13 communication unit.

Claims

1. A battery analysis system comprising: a battery data acquisition unit that acquires, via a network, battery data including a deterioration index value of a secondary battery included in a battery pack; a map generation unit that generates a battery characteristic map including the deterioration index value on a condition axis based on battery data of secondary batteries of the same type acquired from multiple battery packs; a map evaluation value calculation unit that calculates an evaluation value indicating the completeness of the battery characteristic map; and a map transmission unit that transmits the battery characteristic map to the battery pack via the network, wherein the map transmission unit skips transmission of the latest version of the battery characteristic map to the battery pack when a difference between the evaluation value of the battery characteristic map of the version currently being used in the battery pack to which the battery characteristic map is to be transmitted and the evaluation value of the battery characteristic map of the latest version is equal to or less than a threshold.

2. The battery analysis system according to claim 1, wherein the battery data acquisition unit acquires time-series data of a deterioration index value, voltage, current, temperature, and SOC (State Of Charge) of the secondary battery as the battery data, and the map generation unit plots the internal resistance of the secondary battery included in the battery pack within a space described by a plurality of condition axes, including a condition axis of the deterioration index value and at least one condition axis of SOC, temperature, and current, to generate an internal resistance map as the battery characteristic map.

3. The battery analysis system of claim 1, wherein the map evaluation value calculation unit calculates an evaluation value of the battery characteristic map for each category of the deterioration index value, and the map transmission unit calculates the difference between an evaluation value of a partial battery characteristic map of the version currently in use in the battery pack to which the battery characteristic map is to be transmitted, the evaluation value of which is included in a range surrounding the deterioration index value of the battery pack on the condition axis of the deterioration index value, and an evaluation value of the partial battery characteristic map of the latest version, and if the difference between the evaluation value of the partial battery characteristic map of the version currently in use in the battery pack to which the battery characteristic map is to be transmitted and the evaluation value of the partial battery characteristic map of the latest version is greater than a threshold, the partial battery characteristic map of the latest version is transmitted to the battery pack, and if the difference is equal to or less than the threshold, the partial battery characteristic map of the latest version is not transmitted to the battery pack.

4. The battery analysis system of claim 1, wherein the map evaluation value calculation unit calculates an evaluation value of the battery characteristic map for each category of the deterioration index value, and the map transmission unit calculates the difference between the evaluation value of the partial battery characteristic map of the version currently in use in the battery pack to which the battery characteristic map is to be transmitted, which is included in the range from the deterioration index value of the battery pack in the deterioration progression direction on the condition axis of the deterioration index value, and the evaluation value of the partial battery characteristic map of the latest version, and when the difference between the evaluation value of the partial battery characteristic map of the version currently in use in the battery pack to which the battery characteristic map is to be transmitted and the evaluation value of the partial battery characteristic map of the latest version is greater than a threshold value, the partial battery characteristic map of the latest version is transmitted to the battery pack, and when the difference is equal to or less than the threshold value, the partial battery characteristic map of the latest version is not transmitted to the battery pack.

5. The battery analysis system according to claim 1, wherein the deterioration index value is defined by the SOH (State Of Health) of the secondary battery.

6. The battery analysis system according to claim 1, wherein the deterioration index value is defined by a total charge amount, a total discharge amount, or an elapsed time since the start of use of the secondary battery.

7. The battery analysis system of claim 1, wherein the map evaluation value calculation unit increases the evaluation value of the latest version of the battery characteristic map the greater the change in data from the previous version of the battery characteristic map, and the wider the spread of the distribution of plotted data within the space of the latest version of the battery characteristic map.

8. A battery analysis method comprising the steps of: acquiring battery data via a network, the battery data including a deterioration index value of a secondary battery included in a battery pack; generating a battery characteristic map including the deterioration index value on a condition axis based on battery data of secondary batteries of the same type acquired from a plurality of battery packs; calculating an evaluation value indicating the completeness of the battery characteristic map; and transmitting the battery characteristic map to the battery pack via the network, wherein the step of transmitting the battery characteristic map skips transmission of the latest version of the battery characteristic map to the battery pack when a difference between an evaluation value of the battery characteristic map of a version currently being used in the battery pack to which the battery characteristic map is to be transmitted and an evaluation value of the battery characteristic map of a latest version is equal to or less than a threshold value.

9. A battery analysis program that causes a computer to perform the following processes: acquiring battery data, including a deterioration index value of a secondary battery included in a battery pack, via a network; generating a battery characteristic map, including the deterioration index value on a condition axis, based on battery data of secondary batteries of the same type acquired from multiple battery packs; calculating an evaluation value indicating the completeness of the battery characteristic map; and transmitting the battery characteristic map to the battery pack via the network, wherein the process of transmitting the battery characteristic map skips transmitting the latest version of the battery characteristic map to the battery pack if the difference between the evaluation value of the battery characteristic map of the version currently being used in the battery pack to which the battery characteristic map is to be transmitted and the evaluation value of the battery characteristic map of the latest version is equal to or less than a threshold.

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