Storage battery replacement assisting method, program, and storage battery replacement assisting system

Abstract

This storage battery replacement assisting method is for: estimating the deterioration state of a plurality of storage batteries; selecting, from among the plurality of storage batteries and on the basis of the estimated deterioration state, a storage battery for which replacement is to be recommended; and performing notification of information indicating the selected storage battery.

Description

Battery replacement support method, program, and battery replacement support system

[0001] The present disclosure relates to a storage battery replacement support method, a program, and a storage battery replacement support system.

[0002] Japanese Patent Application Laid-Open Publication No. 2023-70913 describes a battery station that includes a battery exchange facility that exchanges the battery of an electric vehicle with a charged battery, a charging facility that charges the battery removed from the electric vehicle, and a transport route that transports the battery removed from the electric vehicle to the charging facility.

[0003] At the above-mentioned storage battery station, there are cases where a storage battery is replaced with a charged storage battery regardless of its state of deterioration.

[0004] A battery replacement support method in one aspect of the present disclosure estimates the deterioration state of multiple storage batteries, selects a storage battery that is recommended for replacement from among the multiple storage batteries based on the estimated deterioration state, and notifies information indicating the selected storage battery.

[0005] A program in one aspect of the present disclosure causes a computer to execute the steps of estimating the deterioration state of multiple storage batteries, selecting a storage battery recommended for replacement from among the multiple storage batteries based on the estimated deterioration state, and notifying information indicating the selected storage battery.

[0006] A battery replacement support system in one aspect of the present disclosure includes a charging device that charges multiple storage batteries, and a control device that estimates the deterioration state of each of the multiple storage batteries, selects a storage battery from the multiple storage batteries that is recommended for replacement based on the estimated deterioration state, and controls the system to notify information indicating the selected storage battery.

[0007] According to the present disclosure, the difference in the degradation state of a plurality of storage batteries can be reduced compared to when the storage batteries are replaced regardless of their degradation state.

[0008] 1 is a diagram illustrating an example of the functional configuration of a battery replacement assistance system. FIG. 2 is a diagram for explaining the functional configuration of a server that constitutes the battery replacement assistance system. FIG. 3 is a diagram illustrating an example of the hardware configuration of a server that constitutes the battery replacement assistance system. FIG. 4 is a diagram illustrating the relationship between the depth of discharge and the lifespan of a battery. FIG. 5 is a diagram illustrating the relationship between the electrolyte temperature and the lifespan ratio of a battery. FIG. 6 is a diagram illustrating the relationship between the charge rate of a battery and a correction coefficient. FIG. 7 is a diagram illustrating an example of a method for calculating a remaining lifespan score. FIG. 8 is a flowchart illustrating an example of processing by the battery replacement assistance system. FIG. 9 is a flowchart illustrating an example of processing by the battery replacement assistance system. FIG. 10 is a diagram illustrating an example of a method for calculating a total score. FIG. 11 is a diagram illustrating an example of a total score for each battery ID stored in a database. FIG. 12 is a diagram illustrating an example of output content indicating a battery that is recommended for replacement. FIG. 13 is a diagram illustrating a modified example of output content indicating a battery that is recommended for replacement. FIG. 14 is a diagram illustrating a modified example of output content indicating a battery that is recommended for replacement.

[0009] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or equivalent elements are designated by the same reference numerals, and redundant description will be omitted.

[0010] [System Configuration] The battery replacement support system 100 is a computer system that stores information indicating the degradation state of the storage battery 40 in a database 20 at predetermined time intervals and notifies information indicating a storage battery 40 recommended for replacement from among multiple storage batteries 40 connected to a charging device 2. The degradation state indicates the degree to which the performance of the storage battery 40 has deteriorated from its new state at the time of manufacture. Furthermore, indicators of the degradation state include, for example, a remaining life score, a SOH-P score, a short-circuit behavior score, and a monthly charging rate score, which will be described in detail later. Examples of types of storage batteries 40 include, but are not limited to, lead-acid batteries, lithium-ion batteries, and zinc batteries. The storage battery 40 may also be a battery pack composed of multiple cells of the same type.

[0011] The storage battery 40 is mounted on a storage battery-equipped device 41. The storage battery-equipped device 41 refers to a device that operates using all or part of the electrical energy stored in the storage battery 40 as its power source. The storage battery-equipped device 41 may be, for example, an electric vehicle configured to be movable using the mounted storage battery 40 as its power source, or may be a robot. The electric vehicle may be a vehicle for carrying people or a vehicle for moving cargo. The electric vehicle may be an aerial work vehicle that has the function of moving people vertically, or may be a cargo handling vehicle that has the function of moving cargo vertically. The cargo handling vehicle may be, for example, a forklift or an automated guided vehicle (AGV).

[0012] In one example, the battery replacement assistance system 100 owns a plurality of forklifts each having the same model vehicle and storage battery 40, and stores information indicating the deterioration state of the storage battery 40 installed in each forklift in the database 20 at predetermined time intervals. Since the frequency of use and workload of each forklift differ depending on the location of use, the lifespan of the storage battery 40 also differs. When the remaining capacity of a storage battery 40 installed in a forklift becomes empty or low during operation at a charging station 1 for charging the storage battery 40, and the storage battery replacement assistance system 100 needs to be replaced with a storage battery 40 with a higher remaining capacity, the battery replacement assistance system 100 notifies the charging station 1 of information indicating the storage battery 40 recommended for replacement from among the plurality of storage batteries 40 connected to the charging device 2.

[0013] 1 is a diagram showing the functional configuration of an example battery exchange assistance system 100. The battery exchange assistance system 100 includes a charging device 2 installed in a charging station 1, a server 10, a database 20, and an information terminal 30. The charging device 2, the server 10, the database 20, and the information terminal 30 are connected to each other via a communication network 31. The communication network 31 is configured by, for example, at least one of the Internet and an intranet.

[0014] The charging device 2 is installed in the charging station 1. A plurality of charging cables 9 are connected to the charging device 2. The charging device 2 charges a plurality of storage batteries 40 via the plurality of charging cables 9. The charging device 2 includes a control unit 3, an operation unit 4, an output unit 5, a charging unit 6, and a communication unit 7.

[0015] The control unit 3 controls the charging device 2 and is configured by, for example, a microcomputer. The control unit 3 accepts operations performed by the operation unit 4 and performs predetermined processing. The control unit 3 also controls output by the output unit 5, charging by the charging unit 6, communication by the communication unit 7, etc.

[0016] The operation unit 4 accepts operations by the user under the control of the control unit 3. The operation unit 4 may be a start button for starting charging, a stop button for stopping charging, an operation panel, or the like. Note that the operation unit 4 is not limited to these.

[0017] The output unit 5 outputs information about the storage battery 40 that recommends replacement under the control of the control unit 3. The output unit 5 may be, for example, a lighting (or blinking) means for lighting (or blinking) a lamp that indicates the connection position of the storage battery 40 that recommends replacement, an audio output means for outputting audio information about the storage battery 40 that recommends replacement, or a display means for displaying information about the storage battery 40 that recommends replacement on a display screen. Note that the output unit 5 is not limited to these.

[0018] When the storage battery 40 is connected to the charging cable 9 and the charging unit 6 receives a command to start charging, the charging unit 6 charges the storage battery 40 via the charging cable 9 under the control of the control unit 3. Furthermore, when the charging unit 6 receives a command to stop charging or when the storage battery 40 is fully charged, the charging unit 6 stops charging under the control of the control unit 3. Here, "fully charged" refers to a state in which sufficient electricity is stored in the storage battery 40, and refers to, for example, a state in which the state of charge (SOC: State of Charge), which indicates the state of charge of the storage battery 40, is 100% or higher.

[0019] The communication unit 7 is connected to the server 10 via the communication network 31. In one example, when a new storage battery 40 is connected to the charging device 2, the communication unit 7, under the control of the control unit 3, transmits to the server 10 a storage battery ID that identifies each of the multiple storage batteries 40 connected to the charging device 2, a slot ID that identifies the connection position of the storage battery 40, and an SOC that indicates the state of charge of the storage battery 40, in association with each other. The storage battery ID is an identifier that uniquely identifies the storage battery 40. The slot ID is an identifier that uniquely identifies the connection position of the storage battery 40.

[0020] The server 10 is a computer that can be connected to the database 20, the communication unit 7, or the information terminal 30 via a communication network 31. The database 20 stores storage battery data indicating the state of at least one storage battery 40. The storage battery data includes an overall score that is an index of the deterioration state of the storage battery 40. The database 20 may be provided in the server 10 or in the charging station 1. Furthermore, the database 20 may be a component of the storage battery exchange assistance system 100, or may be provided in a computer system separate from the storage battery exchange assistance system 100.

[0021] The information terminal 30 is a computer that can be connected to the server 10 or the charging device 2 via a communication network 31, and may be, for example, a personal computer, a smartphone, a tablet terminal, or the like.

[0022] FIG. 2 is a diagram illustrating the functional configuration of the server 10 constituting an example battery replacement assistance system 100. Each battery-equipped device 41 provides battery data to the database 20. In one example, the battery-equipped device 41 includes a battery management unit (BMU) 42 that monitors or controls the battery 40. The BMU 42 repeatedly measures the status of the battery 40 at predetermined intervals and generates battery data indicating the status. The BMU 42 then transmits the battery data to the database 20 via the communication network 31 at predetermined times. The BMU 42 may be provided external to the battery-equipped device 41. The battery data is time-series data that includes information indicating the usage status of the battery 40 over a certain period of time. For example, each record of the battery data includes the date and time of measurement and at least one physical quantity that indicates the usage status of the battery 40 over a certain period of time. Examples of the physical quantity include, but are not limited to, a measured voltage, a measured current, a measured temperature, and an SOC indicating the state of charge. For example, if each record of the storage battery 40 includes a measured current, the measured current when the storage battery 40 is charging is recorded as a positive value, and the measured current when the storage battery 40 is discharging is recorded as a negative value. The storage battery data indicates a physical quantity measured, for example, every 10 seconds. Alternatively, the storage battery data may be an average value of the physical quantity measured over a 10-second period. In the database 20, the storage battery data is associated with, for example, a storage battery ID.

[0023] The server 10 is a computer that estimates the degradation state of the storage batteries 40 based on the storage battery data and notifies the user of the recommended replacement storage batteries 40. The server 10 includes, as functional modules, an acquisition unit 11, a calculation unit 12, an estimation unit 13, a selection unit 14, and an output unit 15.

[0024] The acquisition unit 11 is a functional module that acquires storage battery data. In one example, the acquisition unit 11 acquires, as status information, information indicating the usage status of the storage battery 40 over a certain period of time from the database 20. The acquisition unit 11 also acquires, from the database 20, the latest total score of the storage battery ID that identifies the storage battery 40 connected to the charging device 2.

[0025] The calculation unit 12 is a functional module that uses the acquired storage battery data to calculate a total score that is an index of the degradation state of the storage battery 40 and stores the total score in the database 20. In one example, the calculation unit 12 calculates a remaining life score, a SOH-P score, a short-circuit behavior score, a monthly charging rate score, etc., which will be described in detail later, based on status information that is information indicating the usage state of each of the multiple storage batteries 40 over a certain period of time. Then, the calculation unit 12 calculates a total score using the remaining life score, SOH-P score, short-circuit behavior score, monthly charging rate score, etc., and stores the total score in the database 20 in association with the storage battery ID.

[0026] The estimation unit 13 is a functional module that estimates the degradation state of the storage battery 40 connected to the charging device 2 using the overall score acquired from the database 20. In one example, the estimation unit 13 compares the overall scores of the storage battery IDs corresponding to the multiple storage batteries 40 connected to the charging device 2 from the database 20, and estimates that the storage battery 40 corresponding to the storage battery ID with a high overall score is a storage battery 40 with a long remaining life and little degradation, and estimates that the storage battery 40 corresponding to the storage battery ID with a low overall score is a storage battery 40 with a short remaining life and much degradation.

[0027] The selector 14 is a functional module that selects a storage battery 40 that is recommended for replacement from among the multiple storage batteries 40 connected to the charging device 2. In one example, the selector 14 selects, from among the storage battery IDs corresponding to the multiple storage batteries 40 connected to the charging device 2, the storage battery 40 that corresponds to the storage battery ID with the highest overall score as the storage battery 40 that is recommended for replacement.

[0028] The output unit 15 is a functional module that outputs processing results. In one example, the output unit 15 notifies information indicating a storage battery 40 that is recommended for replacement from among the multiple storage batteries 40 connected to the charging device 2. In one example, the output unit 15 notifies information such as a storage battery ID indicating a storage battery 40 that is recommended for replacement from among the storage battery IDs corresponding to each of the multiple storage batteries 40 connected to the charging device 2, or the connection position of the storage battery 40 that is recommended for replacement.

[0029] 3 is a diagram showing an example of a general hardware configuration of a computer that constitutes the server 10. For example, the server 10 includes a processor (e.g., a CPU) 101 that executes an operating system, application programs, etc., a main memory unit 102 consisting of ROM and RAM, an auxiliary memory unit 103 consisting of a storage device such as a hard disk or flash memory, a communication control unit 104 consisting of a network card or a wireless communication module, an input device 105 such as a keyboard or a mouse, and an output device 106 such as a monitor.

[0030] Each functional module of the server 10 is realized by loading a predetermined program onto the processor 101 or the main memory unit 102 and having the processor 101 execute the program. In accordance with the program, the processor 101 operates the communication control unit 104, the input device 105, or the output device 106 to read and write data from and to the main memory unit 102 or the auxiliary memory unit 103. Data or databases required for processing are stored in the main memory unit 102 or the auxiliary memory unit 103.

[0031] The server 10 is composed of at least one computer. When multiple computers are used, these computers are connected via a communication network 31 to logically configure one server 10.

[0032] The program for causing a computer or computer system to function as the server 10 includes program code for causing the computer or computer system to function as the acquisition unit 11, calculation unit 12, estimation unit 13, selection unit 14, and output unit 15. This program may be provided in a state where it is non-temporarily recorded on a tangible recording medium such as a CD-ROM, DVD-ROM, or semiconductor memory. Alternatively, the program may be provided via a communications network as a data signal superimposed on a carrier wave. The provided program is stored in, for example, the auxiliary storage unit 103. The processor 101 reads and executes the program from the auxiliary storage unit 103, thereby realizing each of the above-described functional modules.

[0033] Next, we will explain the case where the remaining life rate, the remaining life reduction amount, or the remaining life score based on the remaining life reduction rate is used to estimate the degradation state of the storage battery 40. Here, the remaining life refers to the period from the current state until the end of the life if the same charging and discharging state as up to the present continues. The remaining life reduction amount refers to the amount by which the remaining life has reduced over a certain period of time. The remaining life reduction rate refers to the rate at which the remaining life has reduced over a certain period of time.

[0034] First, a method for calculating the remaining life rate of the storage battery 40 stored in the database 20 using the cumulative discharged amount of electricity will be described.

[0035] In the following, the physical quantities such as current, voltage, and temperature used as storage battery data may be, for example, measured current, voltage, and temperature measured every 10 seconds, or average current, voltage, and temperature, which are the average values ​​of current, voltage, and temperature measured over 10 seconds. This can reduce momentary errors over a predetermined period of time.

[0036] For example, the life of a storage battery 40 for a forklift (hereinafter referred to as FL) mounted on a forklift becomes shorter as the depth of discharge (DOD) becomes deeper, with the relationship shown in Figure 4. The standard life cycle of a FL storage battery is 1200 cycles when repeatedly used at a DOD of 75% of the rated capacity. In this case, if the rated capacity is Cnor (Ah), the amount of electricity discharged until the end of the battery's life, Clife (Ah), is expressed by the following equation (1):

[0037] Clife(Ah)=Cnor・75%・1200=900・Cnor…(1)

[0038] If the cumulative discharge capacity Cdis(Ah) from the new state (also called the initial state) at the time of manufacture is set to ΣI(t), the remaining life rate Rlife at the current time of actual measurement is given by the following formula (2): Here, the remaining life rate Rlife is the ratio of the remaining life at the current time to the initial remaining life, with the initial state being 100% and the end-of-life state being 0%.

[0039] Rlife=1-Cdis / Clife=1-Cdis / (Cnor・900)...(2)

[0040] The life of the storage battery 40 depends on the temperature, and as shown in Fig. 5, the life ratio changes depending on the electrolyte temperature of the storage battery 40. Specifically, assuming that the life ratio at an electrolyte temperature of 30°C is 100%, the life ratio decreases when the electrolyte temperature is higher or lower than 30°C.

[0041] Therefore, the cumulative discharge capacity Cdis(Ah) from the initial state is calculated by converting it into the discharged electrical quantity at a standard temperature of 30° C. by dividing the current value I(t) when the discharge current is applied by a correction coefficient K(T), which is a life ratio that changes depending on the electrolyte temperature, as shown in the following equation (3). In other words, the cumulative discharge capacity Cdis(Ah) is calculated by correcting and integrating the current value I(t) using the correction coefficient K(T) corresponding to the measured temperature acquired every 10 seconds or the average value of the measured temperatures acquired over 10 seconds.

[0042] Cdis(Ah)=Σ{I(t) / K(T)}...(3)

[0043] Here, a correction coefficient K(T), which is a life ratio according to the electrolyte temperature, is stored in the database 20. The correction coefficient K(T) is stored in a data table in 1°C increments within the electrolyte temperature range of -40 to 100°C, for example, and a linear approximation value is used outside this range.

[0044] The life of the storage battery 40 depends on the DOD, and as shown in Figure 4, the life cycle decreases almost linearly at a depth of discharge of 75% DOD or more (i.e., 25% SOC or less). Therefore, when discharging at an SOC of 25% or less, the current value I(t) when the discharge current is flowing is multiplied by a correction coefficient K(SOC) according to the SOC and integrated, and the end of the battery life is estimated when the discharged quantity of electricity reaches the rated value Clife.

[0045] The database 20 stores a correction coefficient K(SOC) corresponding to the SOC, as shown in Fig. 6. The correction coefficient K(SOC) is stored in a data table in 1% increments, and when the SOC exceeds 25% (DOD is less than 75%), the correction coefficient K(SOC) is set to 1, and when the SOC is 25% or less (DOD is 75% or more), the correction coefficient K(SOC) increases two-dimensionally.

[0046] That is, the amount of electricity discharged over a certain period is corrected using a two-dimensional data table based on a correction coefficient K(T) corresponding to the temperature of the storage battery 40 and a correction coefficient K(SOC) corresponding to the SOC of the storage battery 40, and the remaining life rate Rlife is calculated.

[0047] Next, a method for calculating the remaining life reduction amount of the storage battery 40 stored in the database 20 will be described.

[0048] The calculation unit 12 calculates the average voltage, average current, and average temperature from the measured voltage, measured current, and measured temperature for 10 seconds of the storage battery 40 for each storage battery ID obtained from the database 20. The calculation unit 12 then corrects the quantity of electricity Cdis10 (Ah) discharged for 10 seconds using a correction coefficient Kdc(T) corresponding to the calculated average temperature and a correction coefficient Kdc(SOC) corresponding to the SOC. The correction coefficient Kdc(T) and the correction coefficient Kdc(SOC) are extracted from a data table in the database 20 based on the average temperature and SOC during discharge obtained from the storage battery 40 for each storage battery ID.

[0049] The remaining life reduction amount Dlife10 in 10 seconds is expressed as the following equation (4) using the correction coefficient Kdc(T), the correction coefficient Kdc(SOC) (hereinafter referred to as the correction coefficient Kdc(T, SOC)), the discharged amount of electricity Cdis10(Ah) in 10 seconds, and the discharged amount of electricity Clife(Ah) until the end of the life in the above equation (1).

[0050] Dlife10=Kdc(T,SOC)・Cdis10 / Clife...(4)

[0051] In this manner, the calculation unit 12 calculates the remaining life reduction amount from the initial state to the present time by integrating the remaining life reduction amount Dlife10 for 10 seconds.

[0052] Next, a description will be given of a modified method for calculating the remaining life reduction amount of the storage battery 40 stored in the database 20. In this modified example, in addition to the discharged quantity of electricity corrected based on the temperature and SOC at the time of discharge, a charged quantity of electricity corrected based on the temperature and SOC at the time of charge is used.

[0053] The calculation unit 12 calculates the average voltage, average current, and average temperature from the measured voltage, measured current, and measured temperature of the storage battery for each storage battery ID acquired from the database 20 over 10 seconds. The calculation unit 12 then corrects the discharged quantity of electricity Cdis10 (Ah) for 10 seconds and the charged quantity of electricity Cchg10 for 10 seconds using a correction coefficient Kdc(T) corresponding to the calculated average temperature and a correction coefficient Kdc(SOC) corresponding to the SOC. The correction coefficient Kdc(T) and the correction coefficient Kdc(SOC) are extracted from a data table in the database 20 based on the average temperature and SOC acquired from the storage battery for each storage battery ID during charging and discharging. The deterioration ratio Kr during charging and discharging is set to, for example, 50%. As described above, the measured current during charging is acquired as a positive value, and the measured current during discharging is acquired as a negative value.

[0054] The remaining life reduction amount Dlife10 for 10 seconds during discharge is expressed as the following equation (5) using the deterioration ratio Kr, the correction coefficient Kdc(T, SOC), the discharged amount of electricity Cdis10(Ah) for 10 seconds, and the discharged amount of electricity Clife(Ah) until the end of the life in the above equation (1).

[0055] Dlife10=Kr・Kdc(T,SOC)・Cdis10 / Clife…(5)

[0056] In addition, the remaining life reduction amount Dlife10 for 10 seconds during charging is expressed as the following equation (6) using the deterioration ratio Kr, the correction coefficient Kdc(T, SOC), the amount of electricity charged for 10 seconds Cchg10 (Ah), and the amount of electricity discharged until the end of the life Clife (Ah) in the above equation (1).

[0057] Dlife10=(1-Kr)・Kdc(T,SOC)・Cchg10 / Clife ‥(6)

[0058] As described above, during discharge, the discharged quantity of electricity Cdis10 (Ah) for 10 seconds is corrected every 10 seconds according to the temperature and SOC during discharge to calculate the remaining life reduction Dlife10 for 10 seconds during discharge. During charging, the charged quantity of electricity Cchg10 (Ah) for 10 seconds is corrected every 10 seconds according to the temperature and SOC during charging to calculate the remaining life reduction Dlife10 for 10 seconds during charging. The remaining life reduction during charging and discharging from the initial state to the present is then integrated and calculated.

[0059] In the above, the calculation unit 12 can calculate a remaining life reduction rate, which indicates the percentage by which the remaining life has decreased from the initial state to the present time, based on the amount of remaining life reduction from the initial state to the present time.

[0060] The remaining life score is calculated using the remaining life rate and the measurement rate according to the following formula (7). Here, the measurement rate indicates the ratio of the measurement period of the remaining life to the elapsed period from the initial state of the storage battery 40 to the present time. Furthermore, since the remaining life rate is adjusted based on the average value of the cells, it is set so that a remaining capacity of 0% corresponds to a remaining life of 50%.

[0061] Remaining life score = 100% - (100% - remaining life rate%) x measurement rate x 0.5 (7)

[0062] As shown in Figure 7, when the measurement rate is 100%, a remaining life score of 100% is used when the remaining life rate is 100%, and a remaining life score of 50% is used when the remaining life rate is 0%. Also, when the measurement rate is 50%, a remaining life score of 100% is used when the remaining life rate is 100%, and a remaining life score of 75% is used when the remaining life rate is 0%. Also, when the measurement rate is 0%, a remaining life score of 100% is used regardless of the remaining life rate. In other words, the remaining life score is corrected according to the measurement rate. Note that the remaining life rate may be calculated using the remaining life reduction amount or remaining life reduction rate, and the remaining life score may be calculated.

[0063] Next, a case where the SOH-P score based on the SOH-P value is used to estimate the degradation state of the storage battery 40 will be described.

[0064] Here, SOH (State of Health) indicates the deterioration state of the storage battery. Furthermore, SOH-P is a ratio indicating the relationship between a characteristic value in a reference period (hereinafter also referred to as a reference characteristic value) and a characteristic value in a target period (hereinafter also referred to as a target characteristic value), and indicates the proportion of the target characteristic value to the reference characteristic value. In one example, SOH-P is a ratio indicating the relationship between the discharge time in the reference period and the discharge time in the target period. The "reference period" corresponds to the period when the storage battery is new, and the "target period" corresponds to a past period including the present time.

[0065] The database 20 stores the maximum discharge power P ｍａｘ and the minimum driving voltage V ｍｉｎ The battery data including the reference period and the target period is stored.

[0066] In one example, the calculation unit 12 calculates the minimum drive voltage V ｍｉｎ The discharge time required for the CCV to reach the minimum drive voltage V ｍｉｎ The discharge time until the battery-equipped device 41 reaches the maximum discharge power P ｍａｘ The discharge time when constant power discharge is performed by the maximum discharge power P ｍａｘ indicates the power required to operate the battery-equipped device 41 at maximum output. ｍｉｎ is the maximum discharge power P ｍａｘ This indicates the minimum voltage required to output the maximum discharge power P ｍａｘ and the minimum driving voltage V ｍｉｎ is a value set for each storage battery ID, and is recorded in association with the storage battery ID in the database 20, for example.

[0067] That is, the calculation unit 12 calculates the reference data, which is the storage battery data for the reference period, and the minimum driving voltage V ｍｉｎ Based on this, the reference characteristic values ​​such as the discharge time are calculated, and the target data, which is the storage battery data for the target period, and the minimum driving voltage V ｍｉｎBased on the above, a target characteristic value such as the discharge time is calculated, and the ratio of the target characteristic value to the reference characteristic value is calculated, thereby calculating the SOH-P value.

[0068] In other words, when a constant current is discharged, the output voltage of the new storage battery 40 is equal to the minimum drive voltage V ｍｉｎ The SOH-P value is calculated based on the time taken for the output voltage of each of the plurality of storage batteries 40 to drop to the minimum drive voltage relative to the time taken for the output voltage of each of the plurality of storage batteries 40 to drop to the minimum drive voltage.

[0069] As the battery deteriorates, the time it takes for the CCV to reach the minimum drive voltage Vmin from the fully charged voltage becomes shorter, and the SOH-P value gradually decreases from 100% to 0%. In this way, the deterioration state of the battery 40 can be estimated from the SOH-P value, i.e., the relationship between the reference characteristic value and the target characteristic value.

[0070] Next, a case where a short circuit behavior score based on the presence or absence of a short circuit behavior is used to estimate the degradation state of the storage battery 40 will be described.

[0071] If the SOH-P value changes suddenly, it is assumed that a short circuit has occurred, but there are cases where a short circuit has occurred even when the SOH-P value does not change suddenly. For this reason, based on the storage battery data acquired from the database 20, it is determined that a short circuit has occurred in cases such as when the SOC after charging increases suddenly, when the measured voltage drops abnormally after a predetermined time has elapsed since the start of charging, or when the measured voltage after charging ends suddenly drops and is in an unstable state.

[0072] If it is determined that a short circuit behavior has occurred, the short circuit behavior score is set to 50%, and if it is determined that a short circuit behavior has not occurred, the short circuit behavior score is set to 100%.

[0073] Next, we will explain the case where a monthly charging rate score based on the monthly charging rate is used to estimate the deterioration state of the storage battery 40. The monthly charging rate is the ratio of the cumulative monthly charging amount to the cumulative monthly discharging amount. In particular, in flooded lead-acid batteries, which are often used in forklifts, antimony in the positive electrode grid precipitates on the negative electrode as the battery life deteriorates, causing the voltage at the end of charging to decrease and the monthly charging rate to increase. Therefore, if the monthly charging rate increases, it can be detected that the battery is nearing the end of its life.

[0074] The monthly charging rate score is set to 100% if the monthly charging rate is 120% or less. 90% is used if the monthly charging rate is greater than 120% and less than or equal to 130%. 80% is used if the monthly charging rate is greater than 130% and less than or equal to 140%. 70% is used if the monthly charging rate is greater than 140% and less than or equal to 150%. 50% is used if the monthly charging rate is greater than 150% and less than or equal to 200%. 30% is used if the monthly charging rate is greater than 200%. In other words, the monthly charging rate score is corrected according to the monthly charging rate.

[0075] [System Operation] An example of processing by the battery exchange assistance system 100 will be described, along with a battery exchange assistance method according to the present embodiment, with reference to Figures 8A, 8B, 9, and 10. Figure 8A is a flowchart showing an example of processing by the battery exchange assistance system 100 that calculates a total score, which is an index of the degradation state of the storage battery 40, at predetermined time intervals and stores the total score in the database 20. Figure 8B is a flowchart showing an example of processing by the battery exchange assistance system 100 when the storage battery 40 is connected to the charging device 2. Figure 9 is a diagram showing an example of calculation of the total score. Figure 10 is a diagram showing an example of the total score of the storage battery 40 connected to the charging device 2.

[0076] In step S1, the acquisition unit 11 acquires, as status information, information indicating the usage status of the storage battery 40 installed in the storage battery-equipped device 41 over a certain period of time from the database 20. The status information is information indicating the usage status of the storage battery over a certain period of time.

[0077] In step S2, the calculation unit 12 calculates the remaining life, remaining life reduction amount, or remaining life reduction rate of the corresponding storage battery ID based on the acquired status information of the storage battery 40 for each storage battery ID. Then, the calculation unit 12 calculates a remaining life score based on the calculated remaining life, remaining life reduction amount, or remaining life reduction rate. Furthermore, the calculation unit 12 calculates an SOH-P score using the SOH-P value of the corresponding storage battery ID based on the acquired status information of the storage battery 40 for each storage battery ID. Furthermore, the calculation unit 12 determines a short-circuit behavior score of the corresponding storage battery ID based on the acquired status information of the storage battery 40 for each storage battery ID. Furthermore, the calculation unit 12 calculates a monthly charging rate score based on the acquired status information of the storage battery 40 for each storage battery ID.

[0078] 9, the calculation unit 12 calculates a total score from the calculated remaining life score, SOH-P score, short-circuit behavior score, and monthly charging rate score. The total score is calculated based on the remaining life score, SOH-P score, short-circuit behavior score, and monthly charging rate score as shown in the following equation (8).

[0079] Total score = remaining life score × SOH-P score × short circuit behavior score × monthly charge rate score ... (8)

[0080] In step S3, the calculated total score is stored in the database 20 in association with the storage battery ID. That is, the latest total score is stored in the database 20 in association with each storage battery ID.

[0081] Then, when a storage battery 40 is connected to a charging device 2 installed in a charging station 1 and the server 10 receives a storage battery ID that identifies each of the multiple storage batteries 40 connected to the charging device 2, a slot ID that identifies the connection position of the storage battery 40, and an SOC that indicates the charging state of the storage battery 40, the storage battery replacement support system 100 performs the following processing.

[0082] In step S11 , the acquisition unit 11 acquires, from the database 20 , the latest total scores of the IDs of the plurality of storage batteries connected to the charging device 2 .

[0083] In step S12, the estimation unit 13 estimates the degradation state of each of the multiple storage batteries 40 connected to the charging device 2 based on the acquired overall score. The estimation unit 13 estimates that a storage battery 40 with a higher overall score has a longer remaining life and is less deteriorated. In one example, as shown in FIG. 10 , the overall score of storage battery 1 is 65%, which is the highest overall score among storage batteries 1 to 4 connected to the charging device 2, and is estimated to have a longer remaining life and less deterioration. On the other hand, the overall score of storage battery 4 is 8%, which is the lowest overall score among storage batteries 1 to 4 connected to the charging device 2, and is estimated to have a shorter remaining life and more deterioration. In other words, by comparing the overall scores of the multiple storage battery IDs connected to the charging device 2, it is possible to compare the remaining life and compare the degradation states of the multiple storage batteries 40.

[0084] In step S13, the selector 14 selects a storage battery 40 that is recommended for replacement from among the multiple storage batteries 40 connected to the charging device 2, based on the estimated degradation state. In one example, among the storage batteries 40 connected to the charging device 2, a storage battery 40 that has finished charging and has a high overall score is selected as a storage battery 40 that has a long remaining life and is recommended for replacement.

[0085] In step S14, the output unit 15 outputs the processing result. In one example, the output unit 15 outputs (notifies) to the output unit 5 or the information terminal 30 information indicating the storage battery 40 that is recommended for replacement.

[0086] 11, 12A, and 12B are diagrams showing examples of output contents indicating storage batteries 40 that are recommended for replacement.

[0087] 11 shows an example in which a storage battery ID, which is information indicating a storage battery 40 that is recommended for replacement, is output on the display screen of the display device 50 of the charging device 2. The display device 50 displays the storage battery ID indicating the storage battery 40 with the highest overall score as the storage battery 40 that is recommended for replacement, among the multiple storage batteries 40 connected to the charging device 2. This allows the user to replace the storage battery 40 with a storage battery 40 that is less deteriorated. In other words, the difference in the deterioration state of the multiple storage batteries 40 can be reduced compared to when the multiple storage batteries 40 are replaced with a charged storage battery 40 regardless of their deterioration state. In other words, the multiple storage batteries 40 can be used for a longer period of time.

[0088] The storage battery ID, which is information indicating the storage battery 40 for which replacement is recommended, may be output on the display screen of the information terminal 30. That is, the server 10 may transmit the storage battery ID indicating the storage battery 40 with the highest overall score as the storage battery 40 for which replacement is recommended, among the multiple storage batteries 40 connected to the charging device 2, to the information terminal 30 of a predetermined destination, and display the storage battery ID on the display screen of the information terminal 30. That is, the information indicating the storage battery 40 for which replacement is recommended may be notified to the information terminal 30 of a predetermined destination.

[0089] 12A and 12B illustrate an example in which information indicating the connection location of a storage battery 40 recommended for replacement is output by lighting (or blinking) a lamp 51 provided on the charging device 2. As shown in FIG. 12A , the lamp 51 provided at the connection location of the storage battery 40 recommended for replacement lights (or blinks) to indicate the storage battery 40 recommended for replacement. That is, the lamp 51 provided at the connection location of the storage battery 40 with the highest overall score among the storage batteries 40 connected to the charging device 2 lights (or blinks). This allows the user to replace the storage battery 40 with a less deteriorated storage battery 40. In other words, compared to replacing one of the multiple storage batteries 40 with a charged storage battery 40 regardless of its deterioration state, the difference in the deterioration state of the multiple storage batteries 40 can be reduced. That is, the multiple storage batteries 40 can be used for a longer period of time. Furthermore, when there are multiple storage batteries 40 connected to the charging device 2 that have the same overall score obtained from the database 20, multiple lamps 51 provided at the connection positions of the multiple storage batteries 40 that are recommended for replacement may be turned on (or blinking) as shown in FIG. 12B . This allows the user to easily understand that there are multiple storage batteries 40 that are recommended for replacement, and enables the user to replace the storage batteries 40 with any one of the multiple storage batteries 40 with the lit (or blinking) lamps 51. Here, "equivalent" is not limited to "identical" and may include batteries that are substantially the same as each other as long as they are comparable in quality.

[0090] [Modifications] Various examples of the present disclosure have been described above in detail. However, the present disclosure is not limited to the above examples. Various modifications are possible with respect to the present disclosure without departing from the spirit and scope of the present disclosure.

[0091] In the above embodiment, a case has been described in which the degraded state of the storage battery 40 is estimated using a total score calculated from the remaining life score, the SOH-P score, the short-circuit behavior score, and the monthly charging rate score, but the present disclosure is not limited to this, and the degraded state of the storage battery 40 may be estimated using at least one of the remaining life score, the SOH-P score, the short-circuit behavior score, and the monthly charging rate score, or two or more of these scores may be used to estimate the degraded state of the storage battery 40. Even in these cases, the storage battery 40 with the highest score is notified as the storage battery 40 recommended for replacement.

[0092] Furthermore, the selection unit 14 may be configured not to select a storage battery 40 that has a short-circuit behavior and shows signs of reaching the end of its life due to the monthly charging rate, etc., without using the short-circuit behavior score and the monthly charging rate score. This reduces the risk that the operation of the storage battery-equipped device 41 will suddenly stop during operation.

[0093] In the above embodiment, the server 10 calculates the average voltage, average current, and average temperature from the measured voltage, measured current, and measured temperature acquired from the database 20. However, the present disclosure is not limited to this, and the BMU 3 may calculate the average voltage, average current, and average temperature of the measured voltage, measured current, and measured temperature, and transmit storage battery data indicating these average voltages, average currents, and average temperatures to the database 20. In this case, the amount of communication between the BMU 3 and the database 20 can be reduced, and the processing load on the server 10 can be reduced.

[0094] In the present disclosure, when comparing the magnitude of two numerical values, either of the two criteria "greater than or equal to" and "greater than" may be used, or either of the two criteria "less than or equal to" and "less than" may be used.

[0095] In each of the above embodiments, the term "processor" refers to a processor in a broad sense, and includes general-purpose processors (e.g., CPU: Central Processing Unit, etc.) and dedicated processors (e.g., GPU: Graphics Processing Unit, ASIC: Application Specific Integrated Circuit, FPGA: Field Programmable Gate Array, programmable logic device, etc.).

[0096] Furthermore, the operations of the processors in the above embodiments may be performed not only by a single processor but also by multiple processors located at physically separate locations working together. Furthermore, the order of the operations of the processors is not limited to the order described in the above embodiments and may be changed as appropriate.

[0097] [Additional Notes] Preferred aspects of the present disclosure are described below.

[0098] (((1))) A method for supporting battery replacement, comprising: estimating a deterioration state of a plurality of storage batteries; selecting a storage battery recommended for replacement from the plurality of storage batteries based on the estimated deterioration state; and notifying information indicating the selected storage battery.

[0099] (((2))) The storage battery replacement support method according to (((1))), further comprising: estimating the deterioration state based on state information that is information indicating a usage state of each of the plurality of storage batteries over a certain period of time.

[0100] (((3))) The battery replacement support method described in (((1))), in which the deterioration state is estimated based on the time it takes for the output voltage of each of the plurality of storage batteries to drop to its minimum drive voltage relative to the time it takes for the output voltage of a new storage battery to drop to its minimum drive voltage when a constant value of current is discharged.

[0101] (((4))) The storage battery replacement support method according to (((1))), in which information indicating the selected storage battery is notified to an information terminal of a preset destination.

[0102] (((5))) The battery replacement support method according to (((1))), in which information indicating the location of the selected battery is notified by lighting or blinking a lamp.

[0103] (((6))) A battery replacement support method described in any one of (((1))) to (((5))), wherein the plurality of storage batteries are storage batteries mounted on electric vehicles configured to be movable using the storage batteries as a power source.

[0104] ((7)) A program for causing a computer to execute the steps of: estimating the degradation state of a plurality of storage batteries; selecting a storage battery that is recommended for replacement from the plurality of storage batteries based on the estimated degradation state; and notifying information indicating the selected storage battery.

[0105] ((8)) A battery replacement support system comprising: a charging device that charges a plurality of storage batteries; and a control device that estimates the deterioration state of each of the plurality of storage batteries, selects a storage battery that is recommended for replacement from among the plurality of storage batteries based on the estimated deterioration state, and controls to notify information indicating the selected storage battery.

[0106] According to ((1)), ((7)), and ((8)), the difference in the deterioration state of multiple storage batteries can be reduced compared to when the storage batteries are replaced regardless of their deterioration state.

[0107] According to ((2))) and ((3))), the storage battery can be replaced depending on the deterioration state of the storage battery.

[0108] According to ((4))) and ((5))), the user can easily know which storage batteries are recommended for replacement.

[0109] According to ((6)), the difference in the deterioration state of the storage batteries mounted on a plurality of electric vehicles can be reduced compared to when the storage batteries are replaced regardless of their deterioration state.

[0110] The disclosure of Japanese Patent Application No. 2024-021465, filed on February 15, 2024, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards mentioned herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. A battery replacement support method comprising: estimating the deterioration state of a plurality of storage batteries; selecting a storage battery that is recommended for replacement from the plurality of storage batteries based on the estimated deterioration state; and notifying information indicating the selected storage battery.

2. The battery replacement support method according to claim 1, wherein the deterioration state is estimated based on status information that indicates the usage status of each of the plurality of batteries over a certain period of time.

3. A battery replacement support method as described in claim 1, in which the deterioration state is estimated based on the time it takes for the output voltage of each of the plurality of storage batteries to drop to its minimum operating voltage relative to the time it takes for the output voltage of a new storage battery to drop to its minimum operating voltage when a constant current is discharged.

4. The battery replacement support method according to claim 1, wherein information indicating the selected battery is notified to a predetermined destination information terminal.

5. The battery replacement support method according to claim 1, wherein information indicating the location of the selected battery is notified by lighting or flashing a lamp.

6. A battery replacement support method according to any one of claims 1 to 5, wherein the plurality of storage batteries are each mounted on an electric vehicle configured to be movable using the storage battery as a power source.

7. A program for causing a computer to execute the steps of: estimating the deterioration state of a plurality of storage batteries; selecting a storage battery that is recommended for replacement from the plurality of storage batteries based on the estimated deterioration state; and notifying information indicating the selected storage battery.

8. A battery replacement support system comprising: a charging device that charges a plurality of storage batteries; and a control device that estimates the deterioration state of each of the plurality of storage batteries, selects a storage battery that is recommended for replacement from among the plurality of storage batteries based on the estimated deterioration state, and controls the device to notify information indicating the selected storage battery.

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