Secondary battery residual value calculation device, method, and computer program

Abstract

To provide a secondary battery residual value calculation device, a method, and a computer program for calculating a secondary battery residual value corresponding to a purpose of a secondary use.SOLUTION: A secondary battery residual value calculation device 1 includes: a first evaluation value calculation section 103 for acquiring a first capacity X of a secondary battery after the termination of a primary use and a value of a first internal resistance R, and calculating as a first evaluation value, a chargeable / dischargeable time or chargeable / dischargeable electric energy of the secondary battery under a use condition of the secondary use of the secondary battery; a second evaluation value calculation section 104 for acquiring a second capacity X' and a value of a second internal resistance R' of the secondary battery in the past before a time point when the primary use is terminated, and calculating as a second evaluation value, a chargeable / dischargeable time or chargeable / dischargeable electric energy of the secondary battery under the use condition of the secondary use of the secondary battery; a ratio calculation section 105 for calculating a ratio K of the first evaluation value to the second evaluation value; and a residual value calculation section 106 for calculating a residual value at the point of time when the primary use of the secondary battery is terminated based on the ratio K.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] An embodiment of the present invention relates to an apparatus, method, and computer program for calculating a residual value of a secondary battery. [Background technology]

[0002] Currently, secondary batteries are used in various electronic devices. Since secondary batteries deteriorate with use, degraded secondary batteries are replaced with new secondary batteries. Although used secondary batteries have deteriorated from their initial state, they may still be usable for other purposes. For example, a secondary battery that has been used primarily for in-vehicle use may still have a large capacity even if it can no longer perform adequately for driving the vehicle. There is a demand to repurpose such used secondary batteries for other purposes, and standards for the reuse of secondary batteries are being considered.

[0003] The standard for the reuse of secondary batteries states that manufacturers of reused batteries must have clear standards for grading reused batteries, and that they must grade the batteries so that they are assembled into equivalent cells, battery modules, and battery systems in terms of battery capacity retention rate and internal resistance increase rate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-169067 A Summary of the Invention [Problem to be solved by the invention]

[0005] As mentioned above, there are cases where a secondary battery that has been judged to have reached the end of its life for its primary use may still be fully usable for a secondary use that is different in usage. This also suggests that the residual value of a secondary battery will vary depending on the use.

[0006] An embodiment of the present invention has been made in consideration of the above circumstances, and aims to provide a secondary battery residual value calculation device, method, and computer program for calculating the residual value of a secondary battery according to the secondary use application. [Means for solving the problem]

[0007] A secondary battery residual value calculation device according to an embodiment includes a first evaluation value calculation unit that acquires a first capacity and a first internal resistance value of a secondary battery that has completed primary use, and calculates a chargeable / dischargeable time or a chargeable / dischargeable amount of power of the secondary battery under the usage conditions of the secondary use of the secondary battery as a first evaluation value, a second evaluation value calculation unit that acquires a second capacity and a second internal resistance value of the secondary battery that is older than the time when primary use ended, and calculates a chargeable / dischargeable time or a chargeable / dischargeable amount of power of the secondary battery under the usage conditions of the secondary use of the secondary battery as a second evaluation value, a ratio calculation unit that calculates a ratio of the first evaluation value to the second evaluation value, and a residual value calculation unit that calculates a residual value of the secondary battery at the time when primary use ended based on the ratio. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a secondary battery residual value calculation device according to an embodiment. [Diagram 2] FIG. 2 is a diagram showing an example of an equivalent circuit of a secondary battery. [Diagram 3] FIG. 3 is a diagram illustrating an example of a dischargeable time of a secondary battery that is a value calculation target. [Figure 4] FIG. 4 is a flowchart illustrating an example of a method for calculating a residual value of a secondary battery according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an apparatus, method, and computer program for calculating a residual value of a secondary battery according to an embodiment will be described with reference to the drawings.

[0010] FIG. 1 is a diagram illustrating an example of the configuration of a secondary battery residual value calculation device according to an embodiment. The secondary battery residual value calculation device 1 of this embodiment is a computing device equipped with a processor and a memory unit in which a program executed by the processor is recorded, and can realize various functions by software or a combination of software and hardware.

[0011] The secondary battery residual value calculation device 1 includes a control unit 10, a storage unit 12, an input unit 14, an output unit 16, and a communication unit 18. The input unit 14 is connected to an operation means such as a mouse, a keyboard, or a touch panel, and can acquire input information through user operations. The input unit 14 is also connected to an audio input means such as a microphone, and can acquire input audio input information. The input unit 14 records the acquired input information in the storage unit 12.

[0012] The output unit 16 outputs various information to devices connected to the secondary battery residual value calculation device 1. The output unit 16 may include, for example, a display means such as a display, or an audio output means such as a speaker. The output unit 16 outputs visually recognizable information and audibly recognizable information to the output means.

[0013] The communication unit 18 is configured to be able to communicate with other devices via a network such as the Internet or Ethernet (registered trademark). The communication unit 18 can record information acquired from an external device in the storage unit 12, and can transmit information read from the storage unit 12 to the external device.

[0014] The storage unit 12 includes, for example, a main storage unit and an auxiliary storage unit. The main storage unit may include, for example, a read-only memory (ROM) and a random-access memory (RAM). The ROM is a non-volatile memory used exclusively for reading data, and can store data and various setting values ​​used by the control unit 10 (described later) when performing various processes. The RAM may be used as a so-called work area for temporarily storing data when the control unit (described later) performs various processes. The main storage unit of this embodiment is, for example, a RAM, and is used as a memory.

[0015] The auxiliary storage unit is a non-transitory computer-readable storage medium of a computer with the control unit 10 as its core. The auxiliary storage unit is, for example, an EEPROM (registered trademark) (electric erasable programmable read-only memory), a HDD (hard disk drive), or an SSD (solid state drive). The auxiliary storage unit can store a program executed by the control unit 10 described later, data used by the control unit 10 in performing various processes, data generated by the processes in the control unit 10, or various set values. The auxiliary storage unit is a memory that stores various information, and stores, for example, data of the calculation results of the control unit 10, information on the secondary battery that is the subject of the calculation of the residual value (past capacity, past internal resistance, price, charge / discharge characteristics of the secondary battery at the end of primary use (time-series information of voltage against current), etc.), and various parameters used in the calculation (for example, battery life in secondary use, charge end voltage, discharge end voltage, charge / discharge conditions such as charge / discharge current), etc.). The storage unit 12 may also include a memory or HDD externally attached to the secondary battery residual value calculation device 1.

[0016] The control unit 10 can perform a calculation process of the residual value of a secondary battery by executing a program stored in the storage unit 12. Note that the secondary battery for which the residual value is calculated in the secondary battery residual value calculation device 1 of this embodiment may be any of a secondary battery cell, a secondary battery module combining multiple secondary battery cells, and a secondary battery system combining multiple secondary battery modules.

[0017] The control unit 10 includes an internal resistance calculation unit 101, a capacity calculation unit 102, a first SOP calculation unit 103, a second SOP calculation unit 104, a ratio calculation unit 105, and a residual value calculation unit 106. The control unit 10 may also include a function of acquiring time information via, for example, the communication unit 18. The control unit 10 can record past battery performance and information acquired in real time together with the time information in the storage unit 12, and when using the device internal data, it becomes possible to calculate the residual value of the battery taking into account the detailed acquisition time of the secondary battery's past data.

[0018] The internal resistance calculation unit 101 calculates an internal resistance value (first internal resistance value) of a secondary battery that is the subject of value calculation at the time of residual value calculation (at the end of primary use). FIG. 2 is a diagram showing an example of an equivalent circuit of a secondary battery. The equivalent circuit shown in FIG. 2 is an example of a secondary battery equivalent circuit used to calculate the chargeable / dischargeable time in the secondary battery residual value calculation device 1 of this embodiment. In the equivalent circuit of the secondary battery shown in FIG. 2, the battery electromotive force is expressed by the capacitance C of the capacitor, and the internal resistance is expressed by R. When the secondary battery is charged and discharged with a constant current, the electromotive force voltage Vc of the secondary battery increases or decreases at a constant rate. For example, the output voltage Vo of the secondary battery when discharging can be calculated by Vo=Vc-R×i. The output voltage Vo of the secondary battery when charging can be calculated by Vo=Vc+R×i.

[0019] In this embodiment, for example, when the primary use of the secondary battery is completed, the target secondary battery is removed from the electronic device during primary use, and a measurement charging / discharging device (not shown) is connected to the secondary battery, and data required to calculate the capacity and internal resistance of the secondary battery (for example, the charging / discharging characteristics of the secondary battery at the end of primary use (time series information of the output voltage versus the charging / discharging current)) is measured and recorded in memory unit 12.

[0020] The capacity and internal resistance of the secondary battery to be valued may be calculated using measurement information for the period of use in the primary use of the secondary battery. In some secondary battery systems, the BMU (Battery Management Unit) of the secondary battery collects measurement information such as the voltage, current, and temperature of the secondary battery in a time series and calculates the capacity and internal resistance of the secondary battery from sequential calculations, or reports the measurement information to a higher-level cloud server and calculates the capacity and internal resistance of the secondary battery in the cloud server. In these cases, the control unit 10 acquires information measured during primary use, so that it is not necessary to remove the secondary battery from the device used during primary use and measure it with a charging / discharging device for measurement, and it is possible to check the capacity and internal resistance of the battery sequentially without any effort. This makes it possible to easily check the capacity and internal resistance of the secondary battery without measuring the battery characteristics, and to calculate the residual value of the secondary battery at any time.

[0021] In this embodiment, the results of measuring the output voltage Vo when a pulse current is applied to a target secondary battery are stored in advance as time-series information in the storage unit 12. The internal resistance calculation unit 101 can calculate the internal resistance value R, for example, from the relational equation Vo=Vc-R×i based on the above-mentioned equivalent circuit, using the value of the pulse current and the value of the output voltage Vo recorded in the storage unit 12. The internal resistance calculation unit 101 supplies the calculated internal resistance value R to the first SOP calculation unit 103.

[0022] The internal resistance value of the secondary battery when the primary use is completed may be an internal resistance value calculated using a value measured at the stage when the primary use of the secondary battery is completed and stored in advance in the storage unit 12, or an estimated value of the internal resistance value at the time of the primary use completion calculated based on the internal resistance value in an initial state (e.g., a state at the time of shipment from the factory) when the secondary battery is unused may be stored in advance in the storage unit 12. In this case, the internal resistance calculation unit 101 of the control unit 10 may be omitted.

[0023] The capacity calculation unit 102 calculates the capacity (first capacity) of the secondary battery that is the target of the value calculation at the time of residual value calculation (at the end of primary use). The capacity (charge / discharge capacity) of the secondary battery is, for example, the amount of electricity [Ah] discharged from the secondary battery when the secondary battery is discharged from a state where the output voltage Vo is the end of charge voltage (fully charged state) until it reaches a state where the output voltage Vo is the end of discharge voltage (fully discharged state). The capacity X of the secondary battery is calculated by X [Ah] = i × T (the product of the discharge current value and the discharge time), for example, when the time when the secondary battery is discharged from the fully charged state to the fully discharged state with a constant current i [A] is T [h]. The capacity of the secondary battery may be calculated as the amount of electricity [Ah] required to charge the secondary battery from the fully discharged state to the fully charged state. The capacity calculation unit 102 can calculate the capacity X of the secondary battery that is the target of the value calculation at the end of primary use by using the charge / discharge characteristics (time-series information of the output voltage with respect to the charge / discharge current) of the secondary battery at the end of primary use stored in the storage unit 12. The capacity calculation unit 102 supplies the calculated capacity X to the first SOP calculation unit 103.

[0024] The capacity of the secondary battery when the primary use is completed may be calculated using a value measured at the stage when the primary use of the secondary battery is completed and stored in advance in the storage unit 12, or an estimated value of the capacity when the primary use is completed calculated based on the capacity of the secondary battery in an initial state (e.g., a state at the time of shipment from the factory) when the secondary battery is unused may be stored in advance in the storage unit 12. In this case, the capacity calculation unit 102 of the control unit 10 may be omitted.

[0025] The first SOP calculation unit (first evaluation value calculation unit) 103 calculates the dischargeable time or dischargeable power under the usage conditions during secondary use (discharge current or discharge time) as a first evaluation value (first SOP (state of power)) indicating the current value (e.g., at the end of primary use) of the secondary battery whose value is to be calculated. The first SOP calculation unit 103 obtains the capacity X of the secondary battery whose value is to be calculated at the end of primary use, the internal resistance value R at the end of primary use, and the usage conditions during secondary use (charge and discharge current value, charge cut-off voltage, discharge cut-off voltage), and calculates the first SOP.

[0026] For example, the first SOP calculation unit 103 calculates the dischargeable time from a fully charged state in which the secondary battery's electromotive force voltage Vc (or output voltage Vo) becomes the charge end voltage V1 to a discharge end voltage V2, starting discharge under usage conditions (discharge power) according to the intended use from the fully charged state in which the secondary battery's electromotive force voltage Vc (or output voltage Vo) becomes the charge end voltage V1, until the output voltage Vo (or electromotive force voltage Vc) reaches the discharge end voltage V2.

[0027] For example, the capacitance C[F] of an analytical model based on an equivalent circuit of a secondary battery can be calculated as C=di / dVc. If we assume that the charge / discharge capacity of the secondary battery is 1[Ah], the end-of-charge voltage V1 is 2.8[V], and the end-of-discharge voltage V2 is 1.8[V], the available capacitance C[F] of the secondary battery to be calculated can be calculated by the following formula. C=1[Ah]×3600[s] / (2.8[V]-1.8[V])=3600[F]

[0028] The first SOP calculation unit 103 can obtain the battery capacity X [Ah], the charge end voltage V1, and the discharge end voltage V2 of the secondary battery from the storage unit 12, and calculate the capacitance C [F] in the equivalent circuit.

[0029] The first SOP calculation unit 103 uses an analysis model corresponding to an equivalent circuit based on the calculated capacitance C [F] and internal resistance value R [mΩ] to calculate the dischargeable time when the secondary battery is discharged at the discharge current (discharge power) during secondary use by simulation. In this embodiment, the value of the discharge current during secondary use of the secondary battery is a constant value. That is, the first SOP calculation unit 103 uses an analysis model corresponding to an equivalent circuit based on the capacitance C [F] and the internal resistance value R [mΩ] to simulate the output voltage Vo when the target secondary battery is in a fully charged state and outputs (discharges) a constant current (or constant power) as a usage condition during secondary use, and sets the time from the start of discharge until the output voltage Vo reaches the discharge cut-off voltage V2 as the dischargeable time (first SOP). The first SOP calculation unit 103 may use an analysis model corresponding to an equivalent circuit based on the calculated capacitance C [F] and internal resistance R [mΩ] to calculate the chargeable time when the secondary battery is charged with the charging current (charging power) during secondary use as the first SOP by simulation. The first SOP calculation unit 103 records the calculated first SOP value in the storage unit 12 in association with time information.

[0030] The second SOP calculation unit (second evaluation value calculation unit) 104 calculates the dischargeable time or dischargeable power under the usage conditions during secondary use used in calculating the first SOP, using the values ​​of the capacity (second capacity) and internal resistance (second internal resistance) of the secondary battery at a past point in time as a second evaluation value (second SOP) indicating the past value of the secondary battery that is the subject of value calculation. In this embodiment, the second SOP calculation unit 104 obtains the values ​​of the initial capacity X' and internal resistance R' of the secondary battery that is the subject of value calculation (for example, in an unused state at the time of shipment from the storage unit 12), and calculates the second SOP using these values.

[0031] The method of calculating the second SOP is the same as the method of calculating the first SOP described above. That is, the second SOP calculation unit 104 can obtain the battery capacity X' [Ah] of the secondary battery, the end-of-charge voltage V1, and the end-of-discharge voltage V2 from the storage unit 12, and calculate the capacitance C [F] in the equivalent circuit.

[0032] The second SOP calculation unit 104 uses an analysis model corresponding to an equivalent circuit based on the calculated capacitance C' [F] and internal resistance R' [mΩ] to calculate the dischargeable time when the secondary battery is discharged with the discharge current during secondary use by simulation. In this embodiment, the discharge current value of the secondary battery during secondary use is a constant value. That is, the second SOP calculation unit 104 simulates the output voltage Vo when the target secondary battery outputs a constant current (or constant power) in a fully charged state based on the capacitance C [F] and the internal resistance R [mΩ], and sets the time from the start of discharge until the output voltage Vo reaches the discharge end voltage V2 as the dischargeable time (second SOP). The second SOP calculation unit 104 may use an analysis model corresponding to an equivalent circuit based on the calculated capacitance C' [F] and internal resistance R' [mΩ] to calculate the chargeable time when the secondary battery is charged with the charge current (charging power) during secondary use as the second SOP by simulation. The second SOP calculation unit 104 records the calculated second SOP value in the storage unit 12.

[0033] FIG. 3 is a diagram illustrating an example of a dischargeable time of a secondary battery that is a value calculation target. FIG. 3 shows an example of the initial characteristics (for example, characteristics at the time of shipment from the factory) of a secondary battery that is the subject of value calculation and the characteristics at the end of primary use, that is, the dischargeable time when discharged at a predetermined discharge current.

[0034] The characteristics of a secondary battery show a tendency that the capacity decreases and the internal resistance increases depending on the period of use and the conditions of use. Therefore, the dischargeable time of the battery to be valued is shorter than the past performance, and the change in the chargeable / dischargeable time can be used as an index for judging the performance deterioration of the secondary battery compared to the past. For this reason, in this embodiment, the chargeable / dischargeable time for a predetermined charge / discharge power is used as the evaluation index. In the example shown in FIG. 3, the dischargeable time in the initial characteristics of the secondary battery is 3281 [s], and the dischargeable time in the characteristics of the secondary battery at the end of primary use is 3164 [s].

[0035] In the above explanation of the SOP calculation, an example was explained using a simple equivalent circuit model of the secondary battery, but the equivalent circuit model may be a detailed battery model, and the equivalent circuit model is not particularly limited. For example, in the example shown in Fig. 4, the simulation is performed assuming that the internal resistance of the secondary battery is a constant value, but the simulation may be performed so that the internal resistance value changes with use.

[0036] The first SOP calculation unit 103 and the second SOP calculation unit 104 may calculate the power that can be charged and discharged for a predetermined time (chargeable and dischargeable power amount) as the first evaluation value and the second evaluation value. For example, the amount of power (maximum power) that can be discharged from a fully charged state of the secondary battery in a predetermined time (for example, 10 seconds) or the amount of power (maximum power) that can be charged from a fully discharged state of the secondary battery in a predetermined time (for example, 10 seconds) is used as an index, and the discharge power in a predetermined time is reduced due to a decrease in the battery capacity of the secondary battery or an increase in the internal resistance during discharging. The first SOP calculation unit 103 and the second SOP calculation unit 104 can calculate the dischargeable power when the secondary battery is discharged for a predetermined time as the SOP by simulation using an analysis model corresponding to an equivalent circuit of the electrostatic capacitance C, C' [F] and the internal resistance value R, R' calculated using the capacity X, X' and the internal resistance R, R' of the secondary battery.

[0037] The ratio calculation unit 105 acquires the values ​​of the first SOP and the second SOP from the storage unit 12 (or from the first SOP calculation unit 103 and the second SOP calculation unit 104), and calculates the ratio K (=first SOP / second SOP) [%] between the first SOP and the second SOP. The ratio K using the example shown in FIG. 4 is as follows:

[0038] K=3164[s] / 3281[s]×100=96.4[%] The ratio calculation unit 105 records the calculated ratio K in the storage unit 12 and provides it to the residual value calculation unit 106 .

[0039] Residual value calculation unit 106 calculates the residual value of the secondary battery of the value calculation target based on the value of the first SOP and the value of the second SOP. Residual value calculation unit 106 calculates the residual value of the secondary battery of the value calculation target, for example, using ratio K calculated by ratio calculation unit 105. Residual value calculation unit 106 sets a threshold value for ratio K at which the secondary battery reaches the end of its life, and calculates the value of the secondary battery at the end of primary use from this threshold value and the past cost of the secondary battery.

[0040] For example, if the life of a secondary battery is defined as the point at which the threshold Y of the ratio K of charge / discharge time falls below 70%, and the past battery cost (e.g., at the time of shipment from the factory) is set to 1,000 yen, the remaining value of the secondary battery whose value is to be calculated can be calculated as follows: Residual value = 1000 yen x (96.4-70) / (100-70) = 880 yen

[0041] The residual value calculation unit 106 may calculate the residual value of the secondary battery as a rank according to the ratio K. For example, if the ratio K is 70[%] or less, it may be set as the end of the battery life, and if the ratio K is 100[%] to 90[%], it may be set as A rank corresponding to the past (corresponding to the initial state), if the ratio K is 90[%] to 80[%], it may be set as B rank corresponding to the middle of use, and if the ratio K is 80[%] to 70[%], it may be set as C rank corresponding to the end of the battery life. Based on this rank, the residual value calculation unit 106 may calculate the residual value as 800 yen for A rank, 500 yen for B rank, and 300 yen for C rank, for a new secondary battery costing 1000 yen. In this case, for example, a table showing the correspondence between the ratio K and the rank is stored in the storage unit 12, and the residual value calculation unit 106 can obtain the rank corresponding to the ratio K from the table in the storage unit 12.

[0042] Here, an example in which secondary batteries are ranked into three stages has been described, but the number of stages for ranking is not limited to this, and the number of ranks can be increased or decreased as necessary. The method of calculating the residual value based on the rank is a practical method since it is not necessary to calculate a detailed residual value according to the remaining performance of the secondary battery. In addition, since the value of the secondary battery is classified into the number of ranks, it becomes easier for users who reuse secondary batteries to select a secondary battery.

[0043] Furthermore, the residual value calculation unit 106 may calculate the residual value of the secondary battery to be calculated based on, for example, a comparison result (e.g., a difference between the first SOP and the second SOP) of the first SOP value and the second SOP value. In this case, for example, a table showing the correspondence between the comparison result of the first SOP value and the second SOP value and the rank is stored in the storage unit 12, and the residual value calculation unit 106 can acquire the rank corresponding to the comparison result from the table in the storage unit 12. Note that, when the residual value calculation unit 106 does not calculate the residual value using the ratio K, the ratio calculation unit 105 is omitted, and the first SOP value and the second SOP value are supplied to the residual value calculation unit 106 from the storage unit 12 (or from the first SOP calculation unit 103 and the second SOP calculation unit 104).

[0044] A table showing ranks of residual values ​​of secondary batteries corresponding to the first SOP value and the second SOP value may be recorded in the storage unit 12. The table stored in the storage unit 12 may be prepared for each type of secondary battery, for each use of secondary use, or for each combination of primary use and secondary use.

[0045] The secondary battery residual value calculation device of this embodiment may be incorporated in the BMU or upper control device of the secondary battery system. The data acquired by the secondary battery residual value calculation device may be stored inside a device associated with the secondary battery, such as a BMU, or may be stored as battery characteristic data in an external information collection device, such as a cloud server. This makes it possible to calculate the residual value of the secondary battery by checking the data of the device, such as a BMU, or the external information collection device, and therefore makes it possible to easily check the residual value of the secondary battery.

[0046] Next, an example of a method for calculating the residual value of a secondary battery according to an embodiment will be described. FIG. 4 is a flowchart illustrating an example of a method for calculating a residual value of a secondary battery according to an embodiment. First, the internal resistance calculation unit 101 and the capacity calculation unit 102 calculate the capacity and internal resistance of the secondary battery at the end of primary use for the secondary battery to be valued. In this embodiment, the internal resistance calculation unit 101 and the capacity calculation unit 102 calculate the capacity and internal resistance of the secondary battery using time-series information on the charge and discharge characteristics of the secondary battery at the end of primary use recorded in the storage unit 12. (Step S1)

[0047] Next, the first SOP calculation unit 103 uses the capacity and internal resistance of the secondary battery calculated in step S1 to calculate the chargeable and dischargeable time (first SOP) of the secondary battery at the end of primary use based on the usage conditions (charge and discharge power) corresponding to the usage purpose of the secondary use (step S2).

[0048] Next, the second SOP calculation unit 104 acquires the past (e.g., factory-shipped) capacity and internal resistance values ​​of the secondary battery from the storage unit 12, and calculates the past chargeable / dischargeable time (second SOP) of the secondary battery based on the usage conditions (charge / discharge power) corresponding to the secondary use (step S3). The order in which the first SOP and the second SOP are calculated is not limited to the above, and the first SOP may be calculated after the second SOP is calculated.

[0049] The ratio calculation unit 105 calculates the ratio K (=(first SOP / second SOP)×100) [%] of the chargeable / dischargeable time (first SOP) at the end of primary use to the past chargeable / dischargeable time (second SOP) of the secondary battery (step S4).

[0050] The residual value calculation unit 106 sets the life of the secondary battery in secondary use as the ratio Y of the chargeable / dischargeable time (=(lifetime chargeable / dischargeable time / initial chargeable / dischargeable time)×100) [%], and calculates the residual value of the secondary battery (P×(KY) / (100-Y)) from the ratio K [%] calculated in step S4 and the past cost P of the secondary battery (step S5). The residual value calculation unit 106 only needs to calculate the residual value of the secondary battery to be calculated based on the first SOP value and the second SOP value, and the method of calculating the residual value is not limited to the above. The residual value calculation unit 106 may calculate the residual value of the secondary battery based on a comparison result (e.g., the difference between the first SOP and the second SOP) of the first SOP value and the second SOP value. In that case, step S4 of calculating the ratio K can be omitted.

[0051] The residual value calculation unit 106 records the calculated residual value in the memory unit 12 and can, for example, cause the output unit 16 to display it on a monitor or provide it to an external device via the communication unit 18. The remaining value calculation unit 106 may calculate the remaining value of the secondary battery as a rank according to the ratio K, as described above.

[0052] From the above, according to the secondary battery residual value calculation device, method, and computer program of this embodiment, the SOP estimation technology, which is one of the battery state estimation technologies, is used to calculate the chargeable / dischargeable power or chargeable / dischargeable time as the SOP from the capacity and internal resistance of the secondary battery and the charge / discharge power (or charge / discharge current, charge / discharge time) according to the intended use, and the residual value of the battery to be valued can be calculated by calculating the ratio of the SOP of the secondary battery at the end of primary use to the SOP of the secondary battery in the past.

[0053] As described above, according to the secondary battery residual value calculation device, method, and computer program of this embodiment, by calculating the residual value of a secondary battery, it is possible to present clear standards for calculating the residual value and grading of reused secondary batteries.

[0054] That is, according to the present embodiment, it is possible to provide a secondary battery residual value calculation device, method, and computer program for calculating the residual value of a secondary battery according to the secondary use application.

[0055] The program according to the present embodiment may be transferred in a state where it is stored in an electronic device, or in a state where it is not stored in an electronic device. In the latter case, the program may be transferred via a network, or in a state where it is stored in a storage medium. The storage medium is a non-transitory tangible medium. The storage medium is a computer-readable medium. The storage medium may be in any form, such as a CD-ROM or a memory card, as long as it is capable of storing a program and is computer-readable.

[0056] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0057] 1...residual value calculation device, 10...control unit, 12...storage unit, 14...input unit, 16...output unit, 18...communication unit, 101...internal resistance calculation unit, 102...capacity calculation unit, 103...first evaluation value (first SOP) calculation unit, 104...second evaluation value (second SOP) calculation unit, 105...ratio calculation unit, 106...residual value calculation unit

Claims

1. a first evaluation value calculation unit that acquires a first capacity and a first internal resistance of a secondary battery that has completed primary use, and calculates a chargeable / dischargeable time or a chargeable / dischargeable amount of power of the secondary battery under a usage condition of the secondary use of the secondary battery as a first evaluation value; a second evaluation value calculation unit that acquires values ​​of a second capacity and a second internal resistance of the secondary battery from a time before the end of primary use, and calculates a chargeable / dischargeable time or a chargeable / dischargeable amount of power of the secondary battery under a usage condition of the secondary use of the secondary battery as a second evaluation value; A residual value calculation device for a secondary battery comprising: a residual value calculation unit that calculates a residual value of the secondary battery at the time when primary use of the secondary battery ends based on the first evaluation value and the second evaluation value.

2. 2 . The secondary battery residual value calculation device according to claim 1 , wherein the residual value calculation unit calculates the residual value based on a comparison result between the first evaluation value and the second evaluation value.

3. a ratio calculation unit that calculates a ratio of the first evaluation value to the second evaluation value; The secondary battery residual value calculation device according to claim 1 , wherein the residual value calculation unit calculates the residual value based on the ratio.

4. 2. The device for calculating a residual value of a secondary battery according to claim 1, wherein the second capacity and the second internal resistance are values ​​of capacity and internal resistance when the secondary battery is in an unused state.

5. a storage unit that stores time-series information obtained by measuring current values ​​and output voltage values ​​when the secondary battery that has completed primary use is charged and discharged; a capacity calculation unit that calculates a first capacity value of the secondary battery by multiplying the current value and a charging / discharging time by using the time-series information; and an internal resistance calculation unit that calculates the value of the first internal resistance using the value of the pulse current when a pulse current is applied to the secondary battery in the time series information and the value of the output voltage of the secondary battery.

6. a storage unit that stores the cost of the secondary battery at the past time point; The secondary battery residual value calculation device of claim 3, wherein the residual value calculation unit sets a threshold value Y for the ratio at which the secondary battery reaches the end of its life in the secondary use, and calculates the residual value as P x (K-Y) / (100-Y) when the ratio is K and the cost of the secondary battery is P.

7. a storage unit that stores a table in which the ratio corresponds to a rank of the residual value; 4. The secondary battery residual value calculation device according to claim 3, wherein the residual value calculation unit calculates the rank of the residual value according to the ratio from the table.

8. 2. The device for calculating a residual value of a secondary battery according to claim 1, wherein the chargeable / dischargeable time is a time during which the secondary battery can be charged / discharged by charge / discharge power in secondary use of the secondary battery.

9. 2. The device for calculating residual value of a secondary battery according to claim 1, wherein the chargeable / dischargeable amount of electric power is the amount of electric power that can be charged / discharged by the secondary battery during a time period during which the secondary battery can be charged / discharged in secondary use.

10. using a first capacity and a first internal resistance of the secondary battery after primary use, calculate a chargeable / dischargeable time or a chargeable / dischargeable electric energy of the secondary battery under a usage condition of the secondary use of the secondary battery as a first evaluation value; calculating, as a second evaluation value, a chargeable / dischargeable time or a chargeable / dischargeable amount of power of the secondary battery under a usage condition of the secondary use of the secondary battery, using values ​​of a second capacity and a second internal resistance of the secondary battery that are older than the time when the primary use ended; A method for calculating a residual value of a secondary battery, the method comprising: calculating a residual value of the secondary battery at a time when primary use of the secondary battery ends based on the first evaluation value and the second evaluation value.

11. A computer program product causing a computer to carry out the method according to claim 10.

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