Battery authenticity determination method, battery authenticity determination device, and program

Abstract

An acquisition unit (41) acquires first data indicating a charging and discharging history in a first period with respect to a determination target battery, and second data indicating a charging and discharging history in a second period which is before the first period. A calculation unit (42) calculates, on the basis of the first data, a first state amount indicating the state amount of the battery in the first period, and calculates, on the basis of the second data, a second state amount indicating an estimated value of the state amount of the battery in the first period. A determination unit (43) performs, on the basis of the first state amount and the second state amount, authenticity determination for determining whether the battery in the first period is an authentic product or a counterfeit. An output unit (44) outputs the result of the authenticity determination.

Description

[Technical field]

[0001] The present disclosure relates to a method for determining authenticity of a battery, a device for determining authenticity of a battery, and a program. [Background technology]

[0002] The following Patent Document 1 discloses a battery authentication system that determines the authenticity of a battery based on a battery pack ID assigned to an ECU of the battery pack.

[0003] According to the battery authentication system disclosed in the above-mentioned Patent Document 1, if only the battery cell is replaced with a counterfeit product, the battery cannot be correctly identified as a counterfeit product. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2012-222945 A Summary of the Invention

[0005] The present disclosure has an object to provide a technique that can correctly determine that a battery is a counterfeit even if only the battery cell has been replaced with a counterfeit.

[0006] A method for determining authenticity of a battery according to one embodiment of the present disclosure includes obtaining, for a battery to be determined, first data indicating a charge / discharge history during a first period and second data indicating a charge / discharge history during a second period prior to the first period, calculating a first state quantity indicating a state quantity of the battery during the first period based on the first data, calculating a second state quantity indicating an estimated value of the state quantity of the battery during the first period based on the second data, determining whether the battery is genuine or a counterfeit during the first period based on the first state quantity and the second state quantity, and outputting a result of the authenticity determination. [Brief description of the drawings]

[0007] [Figure 1] 1 is a block diagram showing a simplified configuration of a battery management system according to an embodiment of the present disclosure. [Diagram 2] 13 is a flowchart showing a first example of an authenticity determination process executed by the server device. [Diagram 3] 5 is a diagram showing an example of a time series change in a full charge capacity value of a battery pack. FIG. [Figure 4] 13 is a flowchart showing a second example of the authenticity determination process executed by the server device. [Diagram 5] FIG. 4 is a diagram showing an example of a distribution of OCV values ​​according to the SOC of a battery pack. [Figure 6] 13 is a flowchart showing a third example of the authenticity determination process executed by the server device. [Figure 7] FIG. 4 is a diagram showing a voltage drop that occurs with a discharge operation of the battery pack. [Figure 8] 1 is a diagram showing an example of a distribution of voltage drop values ​​according to the SOC and discharge current rate of a battery pack; [Figure 9] 13 is a flowchart showing a fourth example of the authenticity determination process executed by the server device. [Figure 10] FIG. 13 is a diagram showing a first modified example of a system configuration. [Figure 11] FIG. 13 is a diagram illustrating a second modified example of the system configuration. [Figure 12] FIG. 13 is a diagram illustrating a third modified example of the system configuration. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] (Findings on which this disclosure is based) Genuine battery packs used in electric motorcycles and other vehicles are expensive and can be resold, so it is expected that counterfeit products will be widely distributed. In order to prevent accidents or vehicle breakdowns caused by the use of inferior counterfeit products and to maintain the fair prices of genuine products, it is necessary to curb the distribution of counterfeit products in the market.

[0009] The above-mentioned Patent Document 1 discloses a battery authentication system for batteries mounted on electric vehicles. In this system, an immobilizer unit compares a first battery pack ID stored in a memory of an ECU equipped in a battery pack with a second battery pack ID stored in a memory of an ECU equipped in a vehicle, and permits the start of the vehicle if the two match, and prohibits the start of the vehicle if the two do not match.

[0010] However, according to the battery authentication system disclosed in the above-mentioned Patent Document 1, if a genuine ECU is used in a battery pack but only the battery cells are replaced with counterfeit ones, the first battery pack ID stored in the ECU's memory will not change, and the immobilizer unit will erroneously determine that the battery pack is genuine.

[0011] In order to solve such problems, the inventor discovered that by recording the charge / discharge history of a battery and determining the authenticity of the battery based on the battery's state quantity that can be calculated from the charge / discharge history, it is possible to detect the need to replace a battery cell when the state quantity suddenly changes significantly, and this led to the present disclosure.

[0012] Next, each aspect of the present disclosure will be described.

[0013] A method for determining authenticity of a battery according to one embodiment of the present disclosure includes a computer acquiring, for a battery having battery cells, first data indicating a charge / discharge history during a first period and second data indicating a charge / discharge history during a second period prior to the first period, calculating a first state quantity indicating a state quantity of the battery during the first period based on the first data, calculating a second state quantity indicating an estimated value of the state quantity of the battery during the first period based on the second data, determining whether the battery is genuine or a counterfeit during the first period based on the first state quantity and the second state quantity, and outputting a result of the authenticity determination.

[0014] According to this aspect, a first state quantity indicating the state quantity of the battery in the first period is calculated based on the first data, and a second state quantity indicating an estimated value of the state quantity of the battery in the first period is calculated based on the second data. When a genuine battery cell is replaced with a counterfeit, the first state quantity and the second state quantity are significantly different before and after the replacement, so that it is possible to detect that the battery cell has been replaced by determining the authenticity of the battery based on the first state quantity and the second state quantity. As a result, even if only the battery cell is replaced with a counterfeit, it is possible to correctly determine that the battery is a counterfeit.

[0015] In the above aspect, the state amount includes a full charge capacity.

[0016] According to this aspect, the full charge capacity of the battery can be accurately calculated based on the charge and discharge history of the battery, so that the accuracy of the determination can be improved by determining the authenticity of the battery based on the full charge capacity of the battery.

[0017] In the above aspect, in calculating the first state quantity, a plurality of full charge capacity values ​​are calculated by calculating the full charge capacity each time the battery is fully charged during the first period based on the first data, and in calculating the second state quantity, an estimate of the full charge capacity of the battery during the first period and an allowable upper limit value and an allowable lower limit value that sandwich the estimate value are calculated based on the second data, and in determining authenticity, a ratio of the number of full charge capacity values ​​that exceed the allowable upper limit value or are less than the allowable lower limit value to the total number of the plurality of full charge capacity values ​​during the first period is calculated as a suspicion rate that the battery is a counterfeit.

[0018] According to this embodiment, rather than choosing between whether the battery is genuine or counterfeit, it is possible to output a suspicion rate indicating the probability that the battery is a counterfeit as the result of authenticity determination.

[0019] In the above aspect, the state quantity includes an open terminal voltage corresponding to a remaining capacity rate.

[0020] According to this aspect, the open terminal voltage corresponding to the remaining capacity rate of the battery can be accurately calculated based on the charge / discharge history of the battery, so that the accuracy of the determination can be improved by determining the authenticity of the battery based on the open terminal voltage corresponding to the remaining capacity rate of the battery.

[0021] In the above aspect, in calculating the first state quantity, a plurality of open terminal voltage values ​​are calculated by calculating the open terminal voltage each time the battery is charged during the first period based on the first data, and in calculating the second state quantity, an estimated value of the open terminal voltage during the first period and an allowable upper limit value and an allowable lower limit value that sandwich the estimated value are calculated based on the second data, and in determining the authenticity, a ratio of the number of the open terminal voltage values ​​that exceed the allowable upper limit value or are less than the allowable lower limit value to the total number of the plurality of open terminal voltage values ​​during the first period is calculated as a suspicion rate that the battery is a counterfeit.

[0022] According to this embodiment, rather than choosing between whether the battery is genuine or counterfeit, it is possible to output a suspicion rate indicating the probability that the battery is a counterfeit as the result of authenticity determination.

[0023] In the above aspect, the state quantity includes a voltage drop corresponding to a remaining capacity rate and a discharge current rate.

[0024] According to this aspect, the voltage drop corresponding to the remaining capacity rate and the discharge current rate of the battery can be accurately calculated based on the charge and discharge history of the battery, so that the accuracy of the determination can be improved by determining the authenticity of the battery based on the voltage drop corresponding to the remaining capacity rate and the discharge current rate of the battery.

[0025] In the above aspect, in calculating the first state quantity, a plurality of drop voltage values ​​are calculated by calculating the drop voltage each time the battery is discharged during the first period based on the first data, and in calculating the second state quantity, an estimated value of the drop voltage during the first period and an allowable upper limit value and an allowable lower limit value that sandwich the estimated value are calculated based on the second data, and in determining the authenticity, a ratio of the number of the drop voltage values ​​that exceed the allowable upper limit value or are less than the allowable lower limit value to the total number of the plurality of drop voltage values ​​during the first period is calculated as a suspicion rate that the battery is a counterfeit.

[0026] According to this embodiment, rather than choosing between whether the battery is genuine or counterfeit, it is possible to output a suspicion rate indicating the probability that the battery is a counterfeit as the result of authenticity determination.

[0027] A battery authenticity determination device according to one embodiment of the present disclosure includes an acquisition unit that acquires, for a battery having battery cells, first data indicating a charge / discharge history during a first period and second data indicating a charge / discharge history during a second period prior to the first period; a calculation unit that calculates a first state quantity indicating a state quantity of the battery during the first period based on the first data and calculates a second state quantity indicating an estimated value of the state quantity of the battery during the first period based on the second data; a determination unit that performs an authenticity determination as to whether the battery is genuine or a counterfeit during the first period based on the first state quantity and the second state quantity; and an output unit that outputs a result of the authenticity determination.

[0028] According to this aspect, the calculation unit calculates a first state quantity indicating the state quantity of the battery in the first period based on the first data, and calculates a second state quantity indicating an estimated value of the state quantity of the battery in the first period based on the second data. When a genuine battery cell is replaced with a counterfeit, the first state quantity and the second state quantity are significantly different before and after the replacement, so that the determination unit determines the authenticity of the battery based on the first state quantity and the second state quantity, thereby detecting that the battery cell has been replaced. As a result, even if only the battery cell is replaced with a counterfeit, the battery can be correctly determined to be a counterfeit.

[0029] A program according to one embodiment of the present disclosure is a program for causing a computer to function as: an acquisition means for acquiring, for a battery having battery cells, first data indicating a charge / discharge history during a first period and second data indicating a charge / discharge history during a second period prior to the first period; a calculation means for calculating a first state quantity indicating a state quantity of the battery during the first period based on the first data, and for calculating a second state quantity indicating an estimated value of the state quantity of the battery during the first period based on the second data; a determination means for determining whether the battery is genuine or a counterfeit during the first period based on the first state quantity and the second state quantity; and an output means for outputting a result of the authenticity determination.

[0030] According to this aspect, the calculation means calculates a first state quantity indicating the state quantity of the battery in the first period based on the first data, and calculates a second state quantity indicating an estimated value of the state quantity of the battery in the first period based on the second data. When a genuine battery cell is replaced with a counterfeit, the first state quantity and the second state quantity are significantly different before and after the replacement, so that the determination means determines the authenticity of the battery based on the first state quantity and the second state quantity, thereby making it possible to detect that the battery cell has been replaced. As a result, even if only the battery cell is replaced with a counterfeit, the battery can be correctly determined to be a counterfeit.

[0031] The present disclosure can be realized as a computer program for causing a computer to execute each characteristic configuration included in such a method, or as an apparatus or system that operates based on this computer program. Furthermore, it goes without saying that such a computer program can be distributed as a computer-readable non-volatile recording medium such as a CD-ROM, or distributed via a communication network such as the Internet.

[0032] Note that each of the embodiments described below shows a specific example of the present disclosure. The numerical values, shapes, components, steps, order of steps, etc. shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, among the components in the following embodiments, components that are not described in an independent claim showing a top concept are described as optional components. Furthermore, in all embodiments, the contents of each can be combined.

[0033] (Embodiments of the present disclosure) Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In addition, elements with the same reference numerals in different drawings indicate the same or corresponding elements.

[0034] 1 is a block diagram showing a simplified configuration of a battery management system according to an embodiment of the present disclosure. In this embodiment, the battery management system manages a plurality of battery packs 2A, 2B mounted on a plurality of vehicles 1A, 1B such as electric motorcycles.

[0035] The battery management system includes a server device 5 connected to a communication network 4. The communication network 4 is, for example, a public line network. The server device 5 is, for example, a cloud server, and functions as an authenticity determination device in the system configuration according to this embodiment.

[0036] The server device 5 includes a communication unit 31, a control unit 32, and a storage unit 33. The communication unit 31 is configured using a communication module for performing wireless communication by any communication method such as IP. The storage unit 33 is configured using a hard disk, an SSD, a semiconductor memory, or the like. A program 51 and history data 52 are stored in the storage unit 33. The control unit 32 is configured using a data processing device such as a CPU. The control unit 32 has an acquisition unit 41, a calculation unit 42, a determination unit 43, and an output unit 44 as functions realized by the CPU executing the program 51.

[0037] The vehicle 1A includes a battery pack 2A and a vehicle control device 3A. The battery pack 2A supplies power to drive a driving motor and the like mounted on the vehicle 1A. The battery pack 2A can be charged in a plug-in manner by receiving power from a commercial power source or the like externally connected to the vehicle 1A.

[0038] The battery pack 2A includes a control unit 11A, a communication unit 12A, a current sensor 13A, a voltage sensor 14A, and a battery cell 15A. The control unit 11A is configured using a data processing device such as a CPU. The communication unit 12A is configured using a communication module for performing wireless communication by any communication method such as Bluetooth (registered trademark). The battery cell 15A is configured using a rechargeable secondary battery such as a lithium-ion battery. The current sensor 13A detects the current value of the charge / discharge current (charging current and discharging current) of the battery cell 15A, and outputs current value data indicating the detected current value. The voltage sensor 14A detects the voltage value between both poles (positive and negative poles) of the battery cell 15A, and outputs voltage value data indicating the detected voltage value.

[0039] The vehicle control device 3A is configured using a part of the functions of, for example, a navigation device of the vehicle 1A. The vehicle control device 3A includes a control unit 21A and communication units 22A and 23A. The control unit 21A is configured using a data processing device such as a CPU. The communication unit 22A is configured using a communication module for wirelessly communicating with the communication unit 12A of the battery pack 2A by an arbitrary communication method such as Bluetooth (registered trademark). The communication unit 23A is configured using a communication module for wirelessly communicating with the communication unit 31 of the server device 5 by an arbitrary communication method such as IP.

[0040] The configuration of vehicle 1B is similar to that of vehicle 1A. Vehicle 1B includes a battery pack 2B and a vehicle control device 3B. Battery pack 2B includes a control unit 11B, a communication unit 12B, a current sensor 13B, a voltage sensor 14B, and a battery cell 15B. Vehicle control device 3B includes a control unit 21B and communication units 22B and 23B.

[0041] In the battery management system according to this embodiment, a server device 5 manages battery packs 2A, 2B mounted on vehicles 1A, 1B. Battery pack IDs, which are identification information for individually identifying the multiple battery packs, are assigned to the battery packs 2A, 2B.

[0042] When a charge / discharge current flows through the battery cell 15A, current value data is input from the current sensor 13A to the control unit 11A, and voltage value data is input from the voltage sensor 14A to the control unit 11A. The control unit 11A inputs the current value data and voltage value data to the communication unit 12A. The current value data and voltage value data include the battery pack ID of the battery pack 2A. The communication unit 12A transmits the current value data and voltage value data to the vehicle control device 3A. The communication unit 22A of the vehicle control device 3A receives the current value data and voltage value data, and inputs the received current value data and voltage value data to the control unit 21A. The control unit 21A inputs the current value data and voltage value data to the communication unit 23A. The communication unit 23A transmits the current value data and voltage value data to the server device 5. The communication unit 31 of the server device 5 receives the current value data and voltage value data, and inputs the received current value data and voltage value data to the control unit 32. The control unit 32 associates the current value data and voltage value data with the battery pack ID of the battery pack 2A contained therein, and stores the data in the storage unit 33. As with the vehicle 1A, the control unit 32 also associates the current value data and voltage value data with the battery pack ID of the battery pack 2B, and stores the data in the storage unit 33 for the vehicle 1B. In this manner, history data 52 indicating the charge and discharge history of each of the battery packs 2A, 2B, associated with the battery pack ID of each of the battery packs 2A, 2B, is accumulated in the storage unit 33.

[0043] 2 is a flowchart showing a first example of the authenticity determination process executed by the server device 5. An example in which the battery pack 2A is the object of determination will be described below, but the process is similar to the case in which the battery pack 2B is the object of determination.

[0044] When an execution command for authenticity determination processing for determining the battery pack 2A is input to the control unit 32, first, the acquisition unit 41 reads out and acquires the history data 52 related to the battery pack 2A from the storage unit 33 in step SP101.

[0045] Next, in step SP102, the calculation unit 42 sets a target period for judgment. In the following, an example of executing the authenticity judgment process of the battery with one month as a unit period will be described. However, the unit period is not limited to one month, and may be any period such as several weeks or months.

[0046] Fig. 3 is a diagram showing an example of a time series change in the full charge capacity value (FCC value) of the battery pack 2A. In the example shown in Fig. 3, the battery pack 2A was shipped in May of this year, and the battery pack 2A had been determined to be a genuine product up until July of the same year. In this case, the calculation unit 42 sets August of the same year, which is the first undetermined month, as the determination target period (determination target month).

[0047] Next, in step SP103, the calculation unit 42 extracts all history data corresponding to charging operations in which charging was performed to a full charge state from the history data 52 related to the battery pack 2A in the determination target month (hereinafter referred to as "full charge data"). The calculation unit 42 calculates an FCC value (first state quantity) for each of all the extracted full charge data. Any algorithm can be used to calculate the FCC value from the current value data and voltage value data included in the full charge data. For example, related data that associates the internal resistance ratio between the initial state and the degraded state of the battery with the full charge capacity ratio between the initial state and the degraded state is created in advance and stored in the storage unit. The calculation unit 42 estimates the internal resistance value of the battery based on the current value data, the voltage value data, and known map information. The calculation unit 42 estimates the FCC value corresponding to each full charge data by determining the full charge capacity ratio corresponding to the internal resistance ratio calculated from the estimated internal resistance value from the related data.

[0048] Next, in step SP104, the calculation unit 42 calculates an estimate (second state quantity) of the FCC value of the battery pack 2A in the determination month based on the history data 52 related to the battery pack 2A in the already determined month. The calculation unit 42 calculates the FCC value for each of all full charge data for each of the already determined months of May to July using the same algorithm as above, and calculates average values ​​X5 to X7 of the multiple FCC values ​​for each month. The calculation unit 42 derives, for example, an approximation line L from the multiple average values ​​X5 to X7 using any estimation algorithm such as approximation by the least squares method or a prediction model by machine learning, and applies the approximation line L to August, which is the determination month, to calculate an estimate value X8 of the FCC value in August.

[0049] Furthermore, the calculation unit 42 calculates an allowable value for the estimated value of the FCC value in the determination month based on the history data 52 for the previously determined month immediately preceding the determination month. The calculation unit 42 calculates the standard deviation σ by statistically processing a plurality of FCC values ​​in July, for example, calculates the allowable upper limit value XU as a value obtained by adding 2×σ to the estimated value X8, and calculates the allowable lower limit value XL as a value obtained by subtracting 2×σ from the estimated value X8.

[0050] Next, in step SP105, the determination unit 43 performs an authenticity determination as to whether the battery pack 2A is a regular product or a counterfeit product in the determination target month based on the first state quantity and the second state quantity. The determination unit 43 determines, for example, whether each of the multiple FCC values ​​as the first state quantity is included in an allowable range including the estimated value X8 as the second state quantity (i.e., a range not larger than the allowable upper limit value XU and not smaller than the allowable lower limit value XL). Then, the determination unit 43 calculates a suspicion rate K1 (=Y1 / Z1×100) indicating the probability that the battery pack 2A is a counterfeit product as a ratio of the number (Y1) of FCC values ​​that exceed the allowable upper limit value XU or are smaller than the allowable lower limit value XL to the total number (Z1) of the multiple FCC values ​​as the first state quantity.

[0051] Next, in step SP106, the output unit 44 outputs data indicating the suspicion rate K1 which is the result of the authenticity determination by the determination unit 43. The administrator of the battery management system can obtain the data indicating the suspicion rate K1 from the server device 5 by accessing the server device 5 via the communication network 4 from a terminal operated by the administrator.

[0052] According to the first example, the FCC value of the battery pack 2A can be accurately calculated based on the charging and discharging history data 52 of the battery pack 2A, so that the accuracy of the authenticity determination of the battery pack 2A can be improved by determining the authenticity of the battery pack 2A based on the FCC value of the battery pack 2A.

[0053] Also, instead of choosing between whether the battery pack 2A is genuine or a counterfeit, it is possible to output a suspicion rate K1 indicating the probability that the battery pack 2A is a counterfeit as the result of authenticity determination.

[0054] 4 is a flowchart showing a second example of the authenticity determination process executed by the server device 5. An example in which the battery pack 2A is the object of determination will be described below, but the process is similar to the case in which the battery pack 2B is the object of determination.

[0055] When an execution command for authenticity determination processing for determining the battery pack 2A is input to the control unit 32, first in step SP201, the acquisition unit 41 acquires the history data 52 related to the battery pack 2A, similarly to the first example described above.

[0056] Next, in step SP202, the calculation section 42 sets the determination target period in the same manner as in the first example.

[0057] Next, in step SP203, the calculation unit 42 extracts all history data (hereinafter referred to as "charging data") corresponding to the charging operation of the battery pack 2A from the history data 52 related to the battery pack 2A in the determination target month. The calculation unit 42 calculates an open circuit voltage value (OCV value; first state quantity) corresponding to the remaining capacity rate (SOC) of the battery pack 2A for each of all the extracted charging data. The calculation unit 42 can calculate the SOC by, for example, a current integration method. The calculation unit 42 can also approximately handle the voltage value data included in the charging data as the OCV value. The calculation unit 42 divides the distribution range of the SOC (for example, 40-100%) into a plurality of SOC regions by dividing it into a predetermined interval (for example, 10%), and calculates, for each charging data, the average value of the plurality of OCV values ​​included in each SOC region as the OCV value corresponding to that SOC region.

[0058] Next, in step SP204, the calculation unit 42 calculates an estimate of the OCV value (second state quantity) corresponding to the SOC of the battery pack 2A in the determination month, based on the history data 52 related to the battery pack 2A in the already determined month.

[0059] 5 is a diagram showing an example of distribution of OCV values ​​according to the SOC of the battery pack 2A. The calculation unit 42 calculates the OCV value according to the SOC for each of all the charge data for each of the determined months of May to July using the same algorithm as above, and calculates the average value of the multiple OCV values ​​for the determined months in each SOC range as the estimated values ​​Y8A to Y8F of the OCV value according to each SOC range.

[0060] Furthermore, calculation unit 42 calculates an allowable value for the estimated OCV value in the determination month based on history data 52 for the previously determined month immediately preceding the determination month. For example, calculation unit 42 calculates standard deviation σ for each SOC region by statistically processing a plurality of OCV values ​​in July, calculates allowable upper limit value YU for each SOC region as a value obtained by adding 2×σ to each estimated value Y8A-Y8F, and calculates allowable lower limit value YL for each SOC region as a value obtained by subtracting 2×σ from each estimated value Y8A-Y8F.

[0061] Next, in step SP205, the determination unit 43 performs an authenticity determination as to whether the battery pack 2A is a regular product or a counterfeit product in the determination target month based on the first state quantity and the second state quantity. The determination unit 43 determines, for example, whether each of the multiple OCV values ​​as the first state quantity is included in an allowable range including each estimated value Y8A to Y8F as the second state quantity (i.e., a range not larger than the allowable upper limit value YU and not smaller than the allowable lower limit value YL). Then, the determination unit 43 calculates a suspicion rate K2 (=Y2 / Z2×100) indicating the probability that the battery pack 2A is a counterfeit product as a ratio of the number (Y2) of OCV values ​​that exceed the allowable upper limit value YU or are smaller than the allowable lower limit value YL to the total number (Z2) of the multiple OCV values ​​as the first state quantity.

[0062] Next, in step SP206, the output unit 44 outputs data indicating the suspicion rate K2, which is the result of the authenticity determination by the determination unit 43.

[0063] According to the second example, the OCV value corresponding to the SOC of the battery pack 2A can be accurately calculated based on the charging and discharging history data 52 of the battery pack 2A, so that the accuracy of the authenticity determination of the battery pack 2A can be improved by determining the authenticity of the battery pack 2A based on the OCV value corresponding to the SOC of the battery pack 2A.

[0064] Also, instead of choosing between whether the battery pack 2A is genuine or a counterfeit, it is possible to output a suspicion rate K2 indicating the probability that the battery pack 2A is a counterfeit as the result of authenticity determination.

[0065] 6 is a flowchart showing a third example of the authenticity determination process executed by the server device 5. An example in which the battery pack 2A is the object of determination will be described below, but the process is similar to the case in which the battery pack 2B is the object of determination.

[0066] When an execution command for authenticity determination processing for determining the battery pack 2A is input to the control unit 32, first in step SP301, the acquisition unit 41 acquires the history data 52 related to the battery pack 2A, similarly to the first example described above.

[0067] Next, in step SP302, the calculation section 42 sets the determination target period in the same manner as in the first example.

[0068] Next, in step SP303, the calculation unit 42 extracts all history data (hereinafter referred to as "discharge data") corresponding to the discharge operation of the battery pack 2A from the history data 52 related to the battery pack 2A in the determination target month. The calculation unit 42 calculates a drop voltage value (first state quantity) corresponding to the SOC and discharge current rate (ratio of the discharge current value to the maximum discharge current value) of the battery pack 2A for each of all the extracted discharge data.

[0069] 7 is a diagram showing a voltage drop that occurs with the discharge operation of the battery pack 2A. At time T1, the throttle of the vehicle 1A is opened to start the discharge operation of the battery pack 2A, and at time T2, the voltage drop ends when the voltage drop rate becomes equal to or lower than a predetermined value (e.g., 0.1 V / sec). The difference (=V1-V2) between the inter-terminal voltage value V1 of both poles (positive and negative poles) of the battery cell 15A at time T1 and the inter-terminal voltage value V2 at time T2 is the voltage drop value.

[0070] The calculation unit 42 can calculate the SOC by, for example, a current integration method. The calculation unit 42 can also treat the current value data included in the discharge data as a discharge current value. The calculation unit 42 can also treat the voltage value data included in the discharge data as a terminal voltage value. The calculation unit 42 divides the distribution range of the SOC (e.g., 50-100%) into a plurality of SOC regions by dividing it into a predetermined interval (e.g., 10%). The calculation unit 42 also divides the distribution range of the discharge current rate (e.g., 50-100%) into a plurality of current rate regions by dividing it into a predetermined interval (e.g., 10%). When the calculation unit 42 detects a voltage drop in each discharge data, it calculates and records a drop voltage value corresponding to an SOC region and a current rate region according to the SOC and discharge current rate of the battery pack 2A at that time.

[0071] Next, in step SP304, the calculation unit 42 calculates an estimate (second state quantity) of the voltage drop value according to the SOC and the discharge current rate of the battery pack 2A in the target month based on the history data 52 related to the battery pack 2A in the already-determined month.

[0072] 8 is a diagram showing an example of distribution of voltage drop values ​​according to the SOC and discharge current rate of the battery pack 2A. The calculation unit 42 calculates a voltage drop value according to the SOC and discharge current rate for each of all discharge data for each of the determined months of May to July using the same algorithm as above, and calculates an average value of a plurality of voltage drop values ​​for the determined month in each SOC region and each current rate region as an estimated value of the voltage drop value according to each SOC region and each current rate region.

[0073] Furthermore, the calculation unit 42 calculates an allowable value for the estimated value of the voltage drop value in the target month based on the history data 52 for the previously determined month immediately preceding the target month. The calculation unit 42 calculates the standard deviation σ for each SOC region and current rate region by statistically processing a plurality of voltage drop values ​​in July, for example, calculates the allowable upper limit value for each SOC region and current rate region as a value obtained by adding 2×σ to each estimated value, and calculates the allowable lower limit value for each SOC region and current rate region as a value obtained by subtracting 2×σ from each estimated value.

[0074] Next, in step SP305, the determination unit 43 performs an authenticity determination as to whether the battery pack 2A is a regular product or a counterfeit product in the determination target month based on the first state quantity and the second state quantity. The determination unit 43 determines, for example, whether each of the multiple drop voltage values ​​as the first state quantity is included in an allowable range including each estimated value as the second state quantity (i.e., a range not greater than an allowable upper limit value and not less than an allowable lower limit value). Then, the determination unit 43 calculates a suspicion rate K3 (=Y3 / Z3×100) indicating the probability that the battery pack 2A is a counterfeit product as a ratio of the number (Y3) of drop voltage values ​​that exceed the allowable upper limit value or are less than the allowable lower limit value to the total number (Z3) of the multiple drop voltage values ​​as the first state quantity.

[0075] Next, in step SP306, the output unit 44 outputs data indicating a suspicion rate K3, which is the result of the authenticity determination by the determination unit 43.

[0076] According to the third example, since the voltage drop value according to the SOC and the discharge current rate of the battery pack 2A can be accurately calculated based on the charge / discharge history data 52 of the battery pack 2A, the accuracy of the determination can be improved by determining the authenticity of the battery pack 2A based on the voltage drop value according to the SOC and the discharge current rate of the battery pack 2A. Note that since the voltage drop value may differ depending on the output of the vehicle in which the battery pack is mounted, the voltage drop value may be calculated separately for each type of vehicle.

[0077] Also, instead of choosing between whether the battery pack 2A is genuine or a counterfeit, it is possible to output a suspicion rate K3 indicating the probability that the battery pack 2A is a counterfeit as the result of authenticity determination.

[0078] 9 is a flowchart showing a fourth example of the authenticity determination process executed by the server device 5. This fourth example is a combination of the above-mentioned first to third examples. However, it is not necessary to combine all of the above-mentioned first to third examples, and examples other than the above-mentioned first to third examples may also be combined.

[0079] When a command to execute an authenticity determination process for determining authenticity of all battery packs managed by the server device 5 is input to the control unit 32, first, in step SP401, the acquisition unit 41 updates the battery pack ID to set the battery pack ID of the battery pack 2A that will be first subjected to the determination.

[0080] Next, in step SP402, the acquisition unit 41 acquires the history data 52 related to the battery pack 2A, similarly to the first example.

[0081] Next, in step SP403, the calculation section 42 sets the determination target period in the same manner as in the first example.

[0082] Next, in step SP404, the calculation section 42 and the determination section 43 calculate the suspicion rate K1 in the same manner as in steps SP103 to SP105.

[0083] Next, in step SP405, the calculation section 42 and the determination section 43 calculate the suspicion rate K2 in the same manner as in steps SP203 to SP205 described above.

[0084] Next, in step SP406, the calculation unit 42 and the determination unit 43 calculate the suspicion rate K3 in the same manner as in steps SP303 to SP305.

[0085] Next, in step SP407, the decision unit 43 calculates a suspicion rate K4 by weighting the suspicion rates K1 to K3 using coefficients W1 to W3 that are equal to or greater than "0," as shown in the following formula (1).

[0086] K4=(W1×K1+W2×K2+W3×K3) / (W1+W2+W3) :(1)

[0087] Next, in step SP408, the output unit 44 outputs data indicating a suspicion rate K4 which is a result of the authenticity determination by the determination unit 43 with the battery pack 2A as the determination target.

[0088] Next, in step SP409, the acquisition section 41 determines whether or not the authenticity determination process for all the battery packs managed by the server device 5 has been completed.

[0089] If there is an undetermined battery pack (step SP409: NO), then in step SP401, the acquisition unit 41 updates the battery pack ID to set the battery pack ID of the battery pack 2B to be determined next. Then, the processes from step SP402 onwards are executed.

[0090] If the authenticity determination process for all the battery packs to be determined is completed (step SP409: YES), the control unit 32 ends the process.

[0091] (summary) According to the battery management system of this embodiment, the calculation unit 42 calculates an FCC value (first state quantity) indicating the state quantity of the battery pack 2A (battery) in a judgment target period (first period) based on the history data 52 (first data) in the first period. The calculation unit 42 also calculates an FCC value (second state quantity) indicating an estimated value of the state quantity of the battery in the first period based on the history data 52 (second data) in a judgment period (second period) before the first period. When the genuine battery cell 15A is replaced with a counterfeit product, the first state quantity and the second state quantity are significantly different before and after the replacement. Therefore, the judgment unit 43 judges the authenticity of the battery based on the first state quantity and the second state quantity, and it is possible to detect that the battery cell 15A has been replaced. As a result, even if only the battery cell 15A is replaced with a counterfeit product, it is possible to correctly judge the battery as a counterfeit product.

[0092] (First Modification) 10 is a diagram showing a first modified example of the system configuration. In this modified example, the battery packs 2A and 2B include storage units 16A and 16B. The storage units 16A and 16B are configured using a semiconductor memory or the like.

[0093] The battery packs 2A, 2B and the server device 5 all function as nodes of the blockchain, and share the same history data 52 in the storage units 16A, 16B, 33 of each node. When the charge / discharge history is updated in any of the battery packs 2A, 2B, update information indicating the update content is transmitted to the other battery packs 2B, 2A and the server device 5 via the communication network 4, and the history data 52 is commonly updated in all the nodes.

[0094] According to this modification, it becomes difficult for a third party to tamper with the history data 52, which makes it possible to improve the security of the system.

[0095] (Second Modification) 11 is a diagram showing a second modified example of the system configuration. In this modified example, a server device 5 such as a cloud server functions as the authenticity determination device 6, but a local PC or a dedicated counterfeit determination device functions as the authenticity determination device 6.

[0096] The battery pack 2 includes a control unit 11, a communication unit 12, a current sensor 13, a voltage sensor 14, a battery cell 15, and a memory unit 16. The memory unit 16 is configured using a semiconductor memory or the like. The communication unit 12 can communicate with a communication unit 31 of the authenticity determination device 6 via wired or wireless communication.

[0097] When a charge / discharge current flows through battery cell 15 in conjunction with the driving operation of the vehicle, current value data is input from current sensor 13 to control unit 11, and voltage value data is input from voltage sensor 14 to control unit 11. Control unit 11 inputs history data 52 including the current value data and voltage value data to storage unit 16, and storage unit 16 accumulates the history data 52.

[0098] When the battery pack 2 is removed from the vehicle and connected to the authenticity determination device 6, the control unit 11 reads out the history data 52 from the storage unit 16 and inputs the history data 52 to the communication unit 12. The communication unit 12 transmits the history data 52 to the authenticity determination device 6. The communication unit 31 of the authenticity determination device 6 receives the history data 52 and inputs the received history data 52 to the control unit 32. The control unit 32 stores the history data 52 in the storage unit 33. Furthermore, the control unit 32 executes an authenticity determination process for determining the battery pack 2 based on the history data 52 read out from the storage unit 33 using a method similar to that of the above embodiment.

[0099] According to this modification, with a simple configuration in which a local PC or the like is used as the authenticity determining device 6, it is possible to realize the authenticity determining process for the battery pack 2.

[0100] (Third Modification) 12 is a diagram showing a third modified example of the system configuration. In this modified example, a charger 7 for charging a battery pack 2 is connected to a server device 5 via a communication network 4.

[0101] When a charge / discharge current flows through battery cell 15 in conjunction with the driving operation of the vehicle, current value data is input from current sensor 13 to control unit 11, and voltage value data is input from voltage sensor 14 to control unit 11. Control unit 11 inputs history data 52 including the current value data and voltage value data to storage unit 16, and storage unit 16 accumulates the history data 52.

[0102] When the battery pack 2 is removed from the vehicle and connected to the charger 7, the control unit 11 reads out the history data 52 from the storage unit 16 and inputs the history data 52 to the communication unit 12. The communication unit 12 transmits the history data 52 to the charger 7. The communication unit 22 of the charger 7 receives the history data 52 and inputs the received history data 52 to the control unit 21. The control unit 21 inputs the history data 52 to the communication unit 23. The communication unit 23 transmits the history data 52 to the server device 5. The communication unit 31 of the server device 5 receives the history data 52 and inputs the received history data 52 to the control unit 32. The control unit 32 stores the history data 52 in the storage unit 33. The control unit 32 also executes an authenticity determination process for the battery pack 2 as the determination target based on the history data 52 read out from the storage unit 33, using the same method as in the above embodiment.

[0103] According to this modification, it is possible to realize the authenticity determination process even for a battery pack 2 mounted on a vehicle that does not support the plug-in system. [Industrial Applicability]

[0104] The present disclosure is particularly useful when applied to a battery management system that manages the status of multiple battery packs mounted on multiple electric motorcycles or the like.

Claims

1. The computer Acquiring first data indicating a charge / discharge history in a first period and second data indicating a charge / discharge history in a second period prior to the first period for a battery having a battery cell; calculating a first state quantity indicating a state quantity of the battery during the first period based on the first data; calculating a second state quantity indicating an estimate of the state quantity of the battery during the first period based on the second data; performing an authenticity determination as to whether the battery is a genuine product or a counterfeit product during the first period based on the first state amount and the second state amount; outputting the result of the authenticity determination; How to determine the authenticity of a battery.

2. The method for determining authenticity of a battery according to claim 1 , wherein the state quantity includes a full charge capacity.

3. In the calculation of the first state quantity, the full charge capacity is calculated each time the battery is fully charged during the first period based on the first data, thereby calculating a plurality of full charge capacity values; In the calculation of the second state quantity, an estimate of the full charge capacity of the battery in the first period and an allowable upper limit value and an allowable lower limit value that are between the estimate value and the full charge capacity of the battery in the first period are calculated based on the second data; 3. The method for determining authenticity of a battery as described in claim 2, wherein in the authenticity determination, a ratio of the number of full charge capacity values ​​that exceed the upper allowable value or are less than the lower allowable value to a total number of the plurality of full charge capacity values ​​during the first period is calculated as a suspicion rate that the battery is a counterfeit.

4. 4. The method for determining authenticity of a battery according to claim 1, wherein the state quantity includes an open terminal voltage corresponding to a remaining capacity rate.

5. In the calculation of the first state quantity, the open-circuit terminal voltage is calculated each time the battery is charged during the first period based on the first data, thereby calculating a plurality of open-circuit terminal voltage values; In the calculation of the second state quantity, an estimate value of the open circuit terminal voltage during the first period and an allowable upper limit value and an allowable lower limit value between the estimate value are calculated based on the second data; 5. The method for determining authenticity of a battery according to claim 4, wherein in the authenticity determination, a ratio of the number of the open terminal voltage values ​​that exceed the upper allowable limit value or are less than the lower allowable limit value to a total number of the plurality of open terminal voltage values ​​in the first period is calculated as a suspicion rate that the battery is a counterfeit.

6. 6. The method for determining authenticity of a battery according to claim 1, wherein the state quantity includes a remaining capacity rate and a voltage drop corresponding to a discharge current rate.

7. In the calculation of the first state quantity, a plurality of voltage drop values ​​are calculated by calculating the voltage drop each time the battery is discharged during the first period based on the first data; In the calculation of the second state quantity, an estimate of the voltage drop during the first period and an allowable upper limit value and an allowable lower limit value that are between the estimate value and the estimated voltage drop during the first period are calculated based on the second data; 7. The method for determining authenticity of a battery as described in claim 6, wherein in the authenticity determination, a ratio of the number of the drop voltage values ​​that exceed the upper allowable limit value or are less than the lower allowable limit value to a total number of the plurality of drop voltage values ​​in the first period is calculated as a suspicion rate that the battery is a counterfeit.

8. an acquisition unit that acquires, for a battery having a battery cell, first data indicating a charge / discharge history in a first period and second data indicating a charge / discharge history in a second period prior to the first period; a calculation unit that calculates a first state quantity indicating a state quantity of the battery in the first period based on the first data, and calculates a second state quantity indicating an estimate of the state quantity of the battery in the first period based on the second data; a determination unit that performs an authenticity determination as to whether the battery is a genuine product or a counterfeit product during the first period based on the first state amount and the second state amount; an output unit that outputs a result of the authenticity determination; A battery authenticity determination device comprising:

9. Computer, An acquisition means for acquiring, with respect to a battery having a battery cell, first data indicating a charge / discharge history in a first period and second data indicating a charge / discharge history in a second period prior to the first period; a calculation means for calculating a first state quantity indicating a state quantity of the battery in the first period based on the first data, and calculating a second state quantity indicating an estimated value of the state quantity of the battery in the first period based on the second data; a determination means for determining whether the battery is a genuine product or a counterfeit product during the first period based on the first state amount and the second state amount; An output means for outputting the result of the authenticity determination; A program to function as a

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