Degradation suppression system, degradation suppression method, degradation suppression program, and storage medium on which degradation suppression program is recorded

Abstract

The histogram generation unit generates, on the basis of the battery data, a histogram of the dwell time of the SOC (State Of Charge) of the battery. The actual SOC range calculation unit specifies, from the histogram, an SOC range that falls within a prescribed probability of occurrence as an actual SOC use range. The recommended SOC range calculation unit calculates a recommended SOC use range in which deterioration is suppressed compared with the actual SOC use range by referring to deterioration characteristics of the battery on the basis of the actual SOC use range and a statistical charge / discharge pattern based on the battery data. The charging recommendation level generation unit generates a charging recommendation level that increases and decreases in accordance with the SOC of the battery, with the lower limit SOC of the recommended SOC use range as a charging start recommendation value and the upper limit SOC of the recommended SOC use range as a charging end recommendation value.

Description

Technical Field

[0001] The present disclosure relates to a degradation suppression system, a degradation suppression method, a degradation suppression program, and a storage medium for suppressing degradation of a battery. Background Art

[0002] In recent years, with the increasing capacity of batteries, devices equipped with rechargeable batteries no longer need to be fully charged at all times, depending on user usage. Furthermore, there are increasing cases where batteries can be used without daily charging. Consequently, limiting the battery's state of charge (SOC) during use to prevent degradation has become increasingly common and effective. To ensure battery durability, it's desirable to systematically charge the required amount.

[0003] However, the timing of charging depends on each user's lifestyle. The goal is to bridge the gap between the SOC at the start or end of charging, which helps prevent degradation, and the SOC at the time each user actually starts or ends charging. Furthermore, the goal is to bridge the gap between each user's perceived remaining battery level and the actual remaining battery level (called the semantic gap). This semantic gap occurs in devices such as EVs, smartphones, and PCs, where charging is based on user judgment.

[0004] Patent Document 1 discloses a method that detects the remaining battery level on the display and the driver's search for charging stations in the car navigation system by capturing a photo of the driver's face. The method then charges the battery until the remaining battery level is slightly above the SOC of concern, thereby controlling charging to a level that the driver is not concerned about. This method minimizes battery degradation by minimizing the SOC. However, this method requires a camera to monitor the driver, which increases the system size. Furthermore, charging automatically stops if the SOC exceeds a certain level, leaving the driver with no final decision.

[0005] Patent Document 2 discloses a method that calculates the SOC range most suitable for suppressing degradation of a power storage device and displays the calculated SOC range along with the SOC of the power storage device. By displaying the SOC range most suitable for suppressing degradation, users are encouraged to perform charging that is optimal for suppressing degradation. However, displaying only the optimal SOC range often leads to users ignoring this SOC range. Furthermore, this method does not help to address semantic gaps.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2022-035232

[0009] Patent Document 2: Japanese Patent Application Laid-Open No. 2021-083187 Summary of the Invention

[0010] The present disclosure has been made in view of such circumstances, and an object of the present disclosure is to provide a technology that can naturally guide the user's charging timing to a charging timing that is most suitable for degradation suppression.

[0011] In order to solve the above-mentioned problems, a degradation suppression system of a certain embodiment of the present disclosure comprises: a histogram generating unit, which generates a histogram of the SOC (State Of Charge) residence time of the battery based on battery data; an actual SOC range calculating unit, which determines an SOC range that falls within a specified probability of occurrence based on the histogram as the actual SOC usage range; a recommended SOC range calculating unit, which calculates a recommended SOC usage range that suppresses degradation compared with the actual SOC usage range based on the actual SOC usage range and a statistical charge and discharge pattern based on the battery data, with reference to the degradation characteristics of the battery; and a charging recommendation degree generating unit, which generates a charging recommendation degree that increases or decreases according to the SOC of the battery, with the lower limit SOC of the recommended SOC usage range as the charging start recommendation value and the upper limit SOC of the recommended SOC usage range as the charging end recommendation value.

[0012] Furthermore, arbitrary combinations of the above-described constituent elements and modes in which the expressions of the present disclosure are converted between devices, systems, methods, computer programs, recording media, and the like may also be additional modes of the present disclosure.

[0013] According to the present disclosure, the user's charging timing can be naturally guided to approach the charging timing most suitable for degradation suppression. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a diagram for explaining a battery-mounted device according to an embodiment.

[0015] Figure 2 It shows Figure 1 Diagram of the functional blocks of the control unit and storage unit of the battery-mounted device.

[0016] Figure 3 This is a diagram showing an example of a histogram of the SOC retention time.

[0017] Figure 4A FIG. 1 is a diagram showing an outline example of a stored degradation characteristic map.

[0018] Figure 4B It is a diagram showing a schematic example of a charge degradation characteristic map.

[0019] Figure 4C It is a diagram showing a schematic example of a discharge degradation characteristic map.

[0020] Figure 5 2 is a diagram showing a display example of the recommended charging level.

[0021] Figure 6 It is a diagram showing an example of display of the recommended charging level based on individual adaptation.

[0022] Figure 7 1 is a diagram showing a time-series display example 1 of the recommended charging level.

[0023] Figure 8 1 is a diagram showing a second time-series display example of the recommended charging level.

[0024] Figure 9 1 is a flowchart showing the basic flow of a process for displaying the recommended charging level. DETAILED DESCRIPTION

[0025] Figure 1 This figure illustrates a battery-mounted device 1 according to an embodiment. The battery-mounted device 1 according to the embodiment is a device equipped with a rechargeable battery pack 50. Examples of battery-mounted devices 1 include portable information terminals (e.g., smartphones, tablets, and laptop computers), some home appliances (e.g., cleaning robots), electric vehicles, electric motorcycles, electric bicycles, electric scooters, and multirotor aircraft (drones). In this embodiment, a smartphone is used.

[0026] The battery-mounted device 1 includes a control unit 10, a storage unit 20, a display unit 30, an operating unit 40, a battery pack 50, a voltage sensor 51, a current sensor 52, a temperature sensor 53, and a charging unit 60. The battery pack 50 is composed of a plurality of single cells or a plurality of parallel single cell blocks connected in series. Each parallel single cell block is composed of a plurality of single cells connected in parallel. Single cells can be lithium-ion battery cells, nickel-metal hydride battery cells, lead-acid battery cells, etc. The following description assumes the use of lithium-ion battery cells (nominal voltage: 3.6V-3.7V).

[0027] The voltage sensor 51 detects the voltage of each of the series-connected cells or parallel-connected cell blocks. The current sensor 52 detects the current flowing through the series-connected cells or parallel-connected cell blocks based on the voltage across a shunt resistor. The shunt resistor is connected in series with the multiple series-connected cells or the multiple parallel-connected cell blocks. Alternatively, a Hall effect element may be used in place of the shunt resistor. The temperature sensor 53 detects the temperature of the multiple cells or parallel-connected cell blocks based on the divided voltage between a thermistor and a resistor provided in at least one of the multiple cells or parallel-connected cell blocks. The voltage detected by the voltage sensor 51, the current detected by the current sensor 52, and the temperature detected by the temperature sensor 53 are output to the control unit 10.

[0028] The control unit 10 comprehensively controls the entire battery-powered device 1. The functions of the control unit 10 can be implemented through the collaboration of hardware and software resources, or solely through hardware resources. Hardware resources include a CPU, ROM, RAM, a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), and other LSIs. Software resources include operating systems, application programs, and other programs.

[0029] The storage unit 20 includes a non-volatile recording medium (NAND flash memory, etc.) for storing various data. The display unit 30 has a liquid crystal display, an organic EL display, a micro LED display, etc., for displaying the image supplied from the control unit 10. The operation unit 40 has physical buttons and a touch panel for accepting user operations and outputting operation signals based on the operation content to the control unit 10. In addition, a touch panel display that integrates the functions of the display unit 30 and the operation unit 40 can also be used. In addition, the above-mentioned program can also be recorded on a recording medium. If the recording medium is used, the above-mentioned program can be installed in, for example, the above-mentioned computer. Here, the recording medium on which the above-mentioned program is recorded can also be a non-transitory recording medium. The non-transitory recording medium is not particularly limited, and for example, it can also be a recording medium such as a CD-ROM.

[0030] The battery pack 50 can be charged from the commercial power system 2. The charging terminal of the battery pack 50 is connected to the commercial power system 2 via the charging unit 60 and the AC adapter 3. The AC adapter 3 converts the 100V / 200V AC voltage input from the commercial power system 2 into a DC voltage of approximately 5V-12V and outputs the converted voltage. Furthermore, if the battery-mounted device 1 is a notebook PC, the AC adapter 3 converts the converted voltage into a DC voltage of approximately 14V-20V and outputs the converted voltage.

[0031] The charging unit 60 includes a DC / DC converter. The DC / DC converter (e.g., a switching regulator) controls the current or voltage of the DC power supplied from the AC adapter 3 according to a current command value or a voltage command value supplied from the control unit 10, and outputs the DC power of the current or voltage specified by the command value to the battery pack 50.

[0032] Figure 2 It shows Figure 1 FIG. 1 is a diagram showing functional blocks of the control unit 10 and the storage unit 20 of the battery-mounted device 1 . Figure 2 The functional blocks shown only depict those related to the degradation suppression system for battery pack 50 according to this embodiment. The control unit 10 includes a battery data acquisition unit 11, an SOC estimation unit 12, a histogram generation unit 13, an actual SOC range calculation unit 14, an actual charge / discharge pattern generation unit 15, an ideal SOC range calculation unit 16, an SOH (State of Health) estimation unit 17, a recommended charge level generation unit 18, a display control unit 19, and a charge / discharge control unit 110. The storage unit 20 includes a battery data storage unit 21, a histogram storage unit 22, a charge degradation characteristic map 23, a discharge degradation characteristic map 24, a stored degradation characteristic map 25, and a charge history storage unit 26.

[0033] The battery data acquisition unit 11 acquires battery data including the voltage, current, and temperature of each cell or each parallel cell block included in the battery pack 50 from the voltage sensor 51 , current sensor 52 , and temperature sensor 53 at a predetermined sampling period (e.g., 10-second intervals, 1-minute intervals).

[0034] The SOC estimation unit 12 estimates the SOC using a combination of the OCV (Open Circuit Voltage) method and the current integration method. The OCV method estimates the SOC based on the OCV of each cell or each parallel cell block, as measured by the voltage sensor 51, and the cell's SOC-OCV curve. The cell's SOC-OCV curve is pre-created based on the battery manufacturer's characteristic tests and is registered in the ROM of the control unit 10 at the time of shipment.

[0035] The current integration method estimates the SOC based on the OCV of each cell or block of parallel cells at the start of charge or discharge, and the integrated value of the current measured by current sensor 52. In the current integration method, the measurement error of current sensor 52 gradually accumulates as charge and discharge time increases. On the other hand, the OCV method is affected by the measurement error of voltage sensor 51 and errors caused by polarization voltage. Therefore, it is preferable to use a weighted average of the SOC estimated using the current integration method and the SOC estimated using the OCV method.

[0036] The SOC estimating unit 12 estimates the SOC of the battery pack 50 based on the SOC of each cell or each parallel cell block. The battery data acquiring unit 11 stores battery data, including the voltage, current, temperature, and SOC of each cell or each parallel cell block, in the battery data storage unit 21. In this case, the battery data acquiring unit 11 may store only the maximum and minimum temperatures among the multiple temperatures measured by the multiple temperature sensors 53 provided in the battery pack 50. Furthermore, the battery data acquiring unit 11 may store both the SOC of all cells or parallel cell blocks and the SOC of the battery pack 50 as a whole, or only the SOC of the battery pack 50 as a whole.

[0037] The histogram generation unit 13 generates a histogram of the SOC retention time of the battery pack 50. The histogram generation unit 13 generates a histogram of the retention time for each SOC level (e.g., every 1% or every 5%). This histogram reflects the user's actual usage of the battery pack 50. The histogram generation unit 13 can generate a histogram of the SOC for the entire period from the start of battery pack 50 use, or for the most recent specified period (e.g., 30 days). In the latter case, unnecessary battery data can be deleted as appropriate.

[0038] The histogram generator 13 may also generate a histogram of SOC dwell time by weekday and weekend, or by day of the week. Furthermore, the histogram generator 13 may generate a histogram that weights data so that the weight of data closest to the most recent data is increased. The histogram generator 13 stores the generated histogram in the histogram storage unit 22.

[0039] The actual SOC range calculation unit 14 fits the SOC dwell time histogram using a Gaussian function and determines the SOC range that falls within a specified probability of occurrence as the actual SOC usage range. For example, the actual SOC range calculation unit 14 determines the SOC range that falls within the range of u±kσ as the actual SOC usage range. k is a constant; for example, when k=2, the SOC range within which approximately 95% of the SOC falls can be determined. Furthermore, data near SOC=100% and 0% are often left unused for extended periods of time and are therefore preferably excluded from the normal distribution fit.

[0040] Figure 3 This is a diagram showing an example of a histogram of SOC dwell time. The horizontal axis is SOC [%], and the vertical axis is dwell time [h]. The actual SOC range calculation unit 14 performs fitting using a Gaussian function and determines the SOC range that falls within the range of u±kσ as the actual SOC usage range.

[0041] Return to Figure 2 The actual charge and discharge pattern generation unit 15 obtains battery data for a target period corresponding to the period for generating the SOC dwell time histogram from the battery data storage unit 21. The actual charge and discharge pattern generation unit 15 generates an actual charge and discharge pattern based on the current data for the target period. In this embodiment, the actual charge and discharge pattern refers to a statistical charge and discharge pattern for one cycle including the charge period and the discharge period.

[0042] The actual charge and discharge pattern generation unit 15 calculates the average value of the charging time. In addition, the average value is a representative value of the charging time, and the median or mode value may be used instead of the average value. The actual charge and discharge pattern generation unit 15 calculates the average value of the charging interval. The charging interval refers to the period from the end of a certain charge to the start of the next charge. The actual charge and discharge pattern generation unit 15 sets the period obtained by adding the average charging time and the average charging interval as the period of the actual charge and discharge pattern. In addition, the histogram generation unit 13 may also calculate the weighted average value of the charging time and the weighted average value of the charging interval in such a way that the weight of the data closest to the most recent data becomes larger, and add the two to set the period of the actual charge and discharge pattern. In this case, it is possible to reflect the more recent utilization trend.

[0043] The actual charge / discharge pattern generation unit 15 generates a current pattern for the charging period of the actual charge / discharge pattern, assuming that an amount of power corresponding to the DOD (Depth of Discharge) of the actual SOC usage range is charged during each charge, and that this amount of power is charged at a constant current during the charging period of the actual charge / discharge pattern. The actual charge / discharge pattern generation unit 15 generates a current pattern for the non-charging period (a combination of a discharge period and a rest period) of the actual charge / discharge pattern, assuming that this amount of power is discharged at a constant current during a single charge interval.

[0044] Furthermore, if the current pattern during the charging period can be extracted from past battery data, the actual charge and discharge pattern generation unit 15 may also set the extracted current pattern as the current pattern during the charging period of the actual charge and discharge pattern. Similarly, if the current pattern during the non-charging period in the actual charge and discharge pattern can be extracted from past battery data, the actual charge and discharge pattern generation unit 15 may also set the extracted current pattern as the current pattern during the non-charging period of the actual charge and discharge pattern. For example, in the case of a timer-type battery-mounted device 1, if the charging period is excluded, the device basically discharges during the set time period and rests during the remaining time period. In this case, the actual charge and discharge pattern generation unit 15 can clearly divide the current pattern during the non-charging period in the actual charge and discharge pattern into the discharge period and the rest period.

[0045] The charge degradation characteristic map 23, discharge degradation characteristic map 24, and storage degradation characteristic map 25 are maps of the charge degradation characteristics, discharge degradation characteristics, and storage degradation characteristics of the cells included in the battery pack 50. The charge degradation characteristics, discharge degradation characteristics, and storage degradation characteristics of the cells are pre-derived through experiments and simulations by the battery manufacturer. Alternatively, data derived by other evaluation organizations may be used.

[0046] Storage degradation is a degradation that progresses over time, depending on the temperature and SOC of a single cell at each point in time. It progresses over time, regardless of whether the battery is being charged or discharged. Storage degradation is primarily caused by the formation of a film (SEI (Solid Electrolyte Interphase) film) on the negative electrode. Storage degradation depends on the SOC and temperature at each point in time. Generally speaking, the higher the SOC at each point in time and the higher the temperature at each point in time, the faster the storage degradation.

[0047] Charge-discharge degradation progresses with increasing charge and discharge cycles. Charge-discharge degradation primarily results from cracking and delamination caused by expansion and contraction of the active material. Charge-discharge degradation depends on the current rate, the SOC range used, and the temperature. Generally speaking, the higher the current rate, the wider the SOC range used, and the higher the temperature, the faster the charge-discharge degradation.

[0048] Figures 4A to 4C 1 is a diagram showing an outline example of a storage degradation characteristic map, a charge degradation characteristic map, and a discharge degradation characteristic map. Figure 4A The following shows an example of a storage degradation characteristic map. The X-axis represents SOC [%], the Y-axis represents temperature [°C], and the Z-axis represents the storage degradation rate [% / √h]. Generally speaking, storage degradation progresses approximately linearly with respect to the value of 0.5 power (square root) of the elapsed time (h). In addition, depending on the type of single cell, it may also progress approximately linearly with respect to the value of 0.4 power, 0.6 power, etc. of the elapsed time (h). Figure 4A As shown, the higher the SOC, the faster the storage degradation rate.

[0049] Figure 4B The following shows an example of a schematic diagram of a charge degradation characteristic map: the X-axis represents the SOC usage range [%], the Y-axis represents the current rate [C], and the Z-axis represents the charge degradation rate [% / √Ah]. Figure 4C This figure shows an example of a discharge degradation characteristic map. The X-axis represents the SOC operating range [%], the Y-axis represents the current rate [C], and the Z-axis represents the discharge degradation rate [% / √Ah]. Generally speaking, charge and discharge degradation progresses approximately linearly with respect to the 0.5 power (square root) of the total charge or discharge capacity (Ah). Depending on the type of battery cell, it may also progress approximately linearly with respect to the 0.4 power, the 0.6 power, or other values ​​of the total charge or discharge capacity (Ah).

[0050] like Figure 4B As shown in the figure, when charging is performed in the low SOC region, the charging degradation rate becomes faster. In addition, when charging is performed in the high SOC region, although not to the same extent as in the low SOC region, the charging degradation rate also becomes faster. Figure 4C As shown, the discharge degradation rate increases when the SOC is lower.

[0051] Furthermore, while the contribution is not solely due to the current rate, the charge-discharge degradation characteristics are also affected by temperature. Therefore, to improve the accuracy of charge-discharge degradation rate estimation, it is preferable to prepare a charge-discharge degradation characteristic that defines the relationship between the SOC usage range and the charge-discharge degradation rate for each of multiple two-dimensional combinations of current rates and temperatures. On the other hand, when generating a simplified charge-discharge degradation characteristic map, the temperature is assumed to be normal, and only the charge-discharge degradation characteristics for each of the multiple current rates are prepared. Furthermore, the storage degradation characteristics, charge degradation characteristics, and discharge degradation characteristics can be defined by functions rather than maps.

[0052] Return to Figure 2 . The ideal SOC range calculation unit 16 searches for an SOC usage range (hereinafter referred to as an ideal SOC usage range) in which the DOD is equal to the actual SOC usage range and the degradation is minimized, referring to the charge degradation characteristic map 23, the discharge degradation characteristic map 24, and the saved degradation characteristic map 25, based on the actual SOC usage range and the actual charge and discharge mode. The ideal SOC range calculation unit 16, for example, moves the actual SOC usage range at a prescribed interval (for example, every 5%, every 1%), and calculates the degradation amount when charging and discharging according to the actual charge and discharge mode is implemented within each SOC usage range. The ideal SOC range calculation unit 16 determines the SOC range with the smallest degradation amount as the ideal SOC usage range. The ideal SOC usage range represents the optimal SOC usage range of the battery pack 50 that should be recommended to the user.

[0053] The SOH estimation unit 17 estimates the SOH of the battery pack 50. For example, the SOH estimation unit 17 calculates the difference (depth of discharge DOD) between the SOC corresponding to the OCV at the start of charging and the SOC corresponding to the OCV at the end of charging, and calculates the current integrated value ΣI during charging.

[0054] The SOH estimation unit 17 estimates the FCC (Full Charge Capacity) based on the depth of discharge (DOD) and the current integrated value ΣI as shown in the following (Equation 1). The SOH estimation unit 17 estimates the SOH based on the estimated FCC and the initial FCC as shown in the following (Equation 2). The SOH is defined by the ratio of the current FCC to the initial FCC. A lower value (closer to 0%) indicates more advanced degradation.

[0055] FCC = ΣI / DOD (Equation 1)

[0056] SOH = Current FCC / Initial FCC (Formula 2)

[0057] The recommended charge level generating unit 18 generates a recommended charge level that increases or decreases according to the SOC of the battery pack 50, using the lower limit SOC of the ideal SOC usage range generated by the ideal SOC range calculating unit 16 as the recommended charge start value and the upper limit SOC as the recommended charge end value. The recommended charge level is not an indicator that directly indicates the SOC of the battery pack 50, but is a separate indicator customized based on the user's usage history, etc.

[0058] The display control unit 19 causes the display unit 30 to display the recommended charging degree generated by the recommended charging degree generating unit 18, as well as at least one of the recommended charge start value and the recommended charge end value. For example, the display control unit 19 can display the recommended charging degree using a bar that expands and contracts according to the SOC of the battery pack 50. In this case, the display control unit 19 can display at least one of the recommended charge start value and the recommended charge end value as scale marks at a predetermined position within the expansion and contraction range of the recommended degree bar.

[0059] Figure 5 : is a diagram showing an example of display of the recommended charging level. Figure 5 In the example shown, the recommended charge level is displayed by a horizontally extending recommended level bar B1. As described above, the recommended level bar B1 does not display the SOC of the battery pack 50 itself, and is therefore displayed separately from the normal remaining battery level display.

[0060] exist Figure 5 In the example, the further the recommended charging level bar B1 stretches to the right, the higher the recommended charging level is, and the further it shrinks to the left, the lower the recommended charging level is. A recommended charging start line, which indicates the recommended charging start value on a scale, and a recommended charging end line, which indicates the recommended charging end value on a scale, are displayed on the recommended charging level bar B1. The positions of the recommended charging start and end lines on the recommended charging level bar B1 are essentially fixed. For example, the recommended charging start line can be drawn at 80% of the total length of the recommended charging level bar B1, and the recommended charging end line can be drawn at 20%.

[0061] Furthermore, the display control unit 19 may not always display both the charge start recommendation line and the charge end recommendation line. For example, the display control unit 19 may display only the charge start recommendation line while the battery-mounted device 1 is in use, and only the charge end recommendation line while the battery-mounted device 1 is charging.

[0062] When charging the battery pack 50, the charge / discharge control unit 110 sets a current command value or a voltage command value for the charging unit 60 based on a predetermined charging schedule to control charging. If the user has selected battery protection mode in the battery mode settings, the charge / discharge control unit 110 automatically stops charging the battery pack 50 when the recommended charge level reaches the recommended charge end value. If the normal mode is selected in the battery mode settings, the charge / discharge control unit 110 does not stop charging even if the recommended charge level reaches the recommended charge end value.

[0063] The recommended charge level generating unit 18 converts the SOC variation within the ideal SOC range of the battery pack 50 into the recommended charge level variation within the range between the recommended charge start value and the recommended charge end value in the recommended level display. The recommended charge level generating unit 18 converts the SOC variation within the range from SOC=0% to the lower limit SOC of the ideal SOC range into the upper limit SOC of the recommended charge level in the recommended level display (in the range between 0% and 10%. Figure 5 The recommended charge degree generating unit 18 converts the change in the SOC from the upper limit SOC of the ideal SOC range to the range of SOC=100% into the change in the recommended charge degree from the recommended charge end value in the recommended degree display to the lower limit of the recommended charge degree (in the range of Figure 5 Changes in the recommended charging level within the range (center is the left end).

[0064] The recommended charge level generator 18 can adjust the rate at which the recommended charge level changes. Furthermore, the recommended charge level generator 18 can add or subtract an offset from the recommended charge level. To advance the user's charging start time while the battery-mounted device 1 is not being charged, the recommended charge level generator 18 increases the rate at which the recommended charge level increases, or adds an offset to the recommended charge level. Conversely, to delay the user's charging start time, the recommended charge level generator 18 decreases the rate at which the recommended charge level increases, or subtracts an offset from the recommended charge level.

[0065] Furthermore, if the battery-equipped device 1 is currently charging and the user wishes to end charging earlier, the recommended charge level generating unit 18 increases the rate at which the recommended charge level decreases or subtracts an offset from the recommended charge level. Conversely, if the user wishes to end charging later, the recommended charge level generating unit 18 decreases the rate at which the recommended charge level decreases or adds an offset to the recommended charge level.

[0066] Based on the current temperature of the battery pack 50 and referring to the charge degradation characteristic map 23, the recommended charge degree generating unit 18 estimates the amount of degradation that would occur if charging were performed at the current temperature. If the estimated amount of degradation that would occur if charging were performed at the current temperature is greater than a threshold, the recommended charge degree generating unit 18 slows the rate of increase of the recommended charge degree or subtracts an offset from the recommended charge degree. If the battery-mounted device 1 is an EV, the amount of degradation is more likely to exceed the threshold when the device is hot immediately after driving or when the outside temperature is low. The recommended degree display is controlled based on the current temperature while the battery-mounted device 1 is not being charged.

[0067] As described above, the charge degradation rate depends on the current rate, the used SOC range, and the temperature. The recommended charge level generating unit 18 sets the charger's charge rate as the current rate, the ideal SOC range as the used SOC range, and the current temperature of the battery pack 50 as the temperature, and refers to the charge degradation characteristic map 23 to derive the charge degradation rate (hereinafter referred to as the charge degradation amount). Furthermore, the recommended charge level generating unit 18 can also derive the degradation amount when the maximum temperature of the battery pack 50 is set, or when the minimum temperature of the battery pack 50 is set.

[0068] If the charge degradation level exceeds the threshold, the recommended charge level generator 18 slows the rate of increase of the recommended charge level or subtracts an offset from the recommended charge level to delay the user's start of charging until the temperature reaches a point where the burden on the battery pack 50 is alleviated. The greater the deviation of the charge degradation level from the threshold, the slower the rate of increase or the larger the offset is subtracted from the recommended charge level. Furthermore, if the actual SOC of the battery pack 50 reaches a lower limit (e.g., 5%), the recommended charge level generator 18 increases the recommended charge level to the recommended charge start value.

[0069] The recommended charge level generating unit 18 may also determine the number of fast charges by referring to the current data of the most recent specified period (e.g., the past month), and slow down the rate of increase of the recommended charge level or subtract an offset from the recommended charge level when the number of fast charges is above a threshold.

[0070] To prevent micro-shortening of the individual cells within the battery pack 50, some battery packs 50 implement control to reduce the full charge voltage as the SOH decreases. In such battery packs 50, the recommended charge level generator 18 can increase the rate of change of the recommended charge level or add or subtract a larger offset to the recommended charge level as the SOH of the battery pack 50 decreases.

[0071] The recommended charge level generator 18, for example, maintains a table (not shown) of the battery pack 50's state of health (SOH) versus full charge voltage. Based on the current SOH, the unit determines the current full charge voltage by referring to the table. The greater the reduction in the current voltage range relative to the initial voltage range, the faster the recommended charge level changes, or the larger the offset added to or subtracted from the recommended charge level to offset the reduction in the voltage range. Furthermore, the recommended charge level generator 18 adds the offset when the battery-mounted device 1 is not being charged and subtracts the offset when it is being charged.

[0072] In addition, the SOC estimation unit 12 determines the current full charge voltage based on the current SOH and with reference to the SOH-full charge voltage table, and calculates the reduction rate of the current voltage usage range relative to the initial voltage usage range. When the SOC usage range is reduced according to the reduction rate and the SOC is generated, there is no need to adjust the change speed or offset of the charging recommendation degree through the charging recommendation degree generation unit 18.

[0073] The charging history storage unit 26 stores a history of the SOC at the start and end of charging of the battery pack 50 by the user. The charge and discharge control unit 110 stores the SOC at the time charging of the battery pack 50 is started (for example, when the charging cable is connected to the battery-mounted device 1) in the charging history storage unit 26. Furthermore, the charge and discharge control unit 110 stores the SOC at the time charging of the battery pack 50 is started (for example, when the charging cable is removed from the battery-mounted device 1 or when a predetermined charging end voltage is reached) in the charging history storage unit 26.

[0074] Based on the difference between the statistical value of the SOC at the start of charging, accumulated in the charging history storage unit 26, and the recommended charge start value, the recommended charge degree generation unit 18 modifies the rate of change of the recommended charge degree, or modifies the offset added to or subtracted from the recommended charge degree, to minimize the difference. Normally, for users who tend to start charging before the recommended charge start value is exceeded, the recommended charge degree generation unit 18 slows the rate of increase of the recommended charge degree. Conversely, for users who tend to start charging after the recommended charge start value is exceeded, the recommended charge degree generation unit 18 accelerates the rate of increase of the recommended charge degree.

[0075] Next, an example of a specific method of changing the increase speed or offset of the recommended charge level will be described. The recommended charge level generating unit 18 calculates the average difference ave by calculating the following (Formula 3).

[0076] ave = Σ(recommended charge start value - actual SOC at charge start) / n (Formula 3)

[0077] n is the number of SOC samples at the start of actual charging

[0078] Furthermore, instead of using the average value of the difference between the recommended charge start value and the SOC at the actual charge start, the median value or mode value of the difference may be used.

[0079] The recommended charge degree generating unit 18 can calculate an increase rate of the recommended charge degree customized for each user by multiplying the normal increase rate of the recommended charge degree by a rate change coefficient based on the average difference ave as shown in the following (Equation 4).

[0080] Individual adaptation rate of increase = normal rate of increase × rate change coefficient (Formula 4)

[0081] Speed ​​change coefficient = ave / reference value

[0082] The recommended charge level generating unit 18 can calculate a recommended charge level customized for each user by adding the average difference ave as an offset to the normal recommended charge level as shown in the following (Equation 5).

[0083] Individually adapted charging recommendation level = normal charging recommendation level + ave... (Equation 5)

[0084] The recommended charge degree generating unit 18 varies the recommended charge degree at an increasing speed adapted to the individual within a range between the recommended charge start value and the recommended charge end value, or adds an offset adapted to the individual to the recommended charge degree.

[0085] The charge recommendation degree generating unit 18 changes the rate of change of the charge recommendation degree, or changes the offset added to or subtracted from the charge recommendation degree, based on the difference between the statistical value of the SOC at the end of charging accumulated in the charge history storage unit 26 and the charge end recommendation value, in such a way as to reduce the difference. Normally, in the case of a user who has a strong tendency to stop charging after exceeding the charge end recommendation value, the charge recommendation degree generating unit 18 speeds up the rate of decrease of the charge recommendation degree. Conversely, in the case of a user who has a strong tendency to stop charging before exceeding the charge end recommendation value, the charge recommendation degree generating unit 18 slows down the rate of decrease of the charge recommendation degree. As a specific method for changing the rate of decrease or the offset of the charge recommendation degree, the method shown in (Formula 3) to (Formula 5) above can be used. It is sufficient to replace the SOC at the actual start of charging with the SOC at the actual end of charging, and to replace the rate of increase of the charge recommendation degree with the rate of decrease of the charge recommendation degree.

[0086] Figure 6 1 is a diagram showing an example of display of the recommended charging level adapted to an individual. Figure 6Shows examples of displays during non-charging periods (i.e., periods when the recommended charging level is increasing). The top recommendation level bar B1a shows an example of a display for users who usually charge in advance. The middle recommendation level bar B1b shows a normal display example. The bottom recommendation level bar B1c shows an example of a display for users who usually delay charging.

[0087] For users who have an early start time for charging, the recommended level bar B1a is extended later, as shown above, to encourage the user to naturally delay the start of charging. Conversely, for users who have a late start time for charging, the recommended level bar B1c is extended earlier, as shown below, to encourage the user to naturally advance the start time of charging.

[0088] During the charging period (i.e., when the recommended charging level is decreasing), for users who finish charging late, the recommended level bar will be extended earlier, encouraging them to naturally end charging earlier. Conversely, for users who finish charging early, the recommended level bar will be extended later, encouraging them to naturally end charging later.

[0089] exist Figure 5 、 Figure 6 While an example of displaying the instantaneous value of the recommended charging level is shown in FIG, a time-series display of the recommended charging level can also be performed, displaying the instantaneous value of the recommended charging level in a time-series manner. The recommended charging level generation unit 18 can predict the future SOC transition based on the SOC transition of the battery pack 50 from a predetermined period of time to the present, and thus predict the future transition of the recommended charging level. The display control unit 19 can display the predicted transition of the recommended charging level in a time-series manner.

[0090] Recommended charge level generating unit 18 calculates the SOC slope for the target period based on the sampled SOC values ​​of the battery pack 50 during the target period from a predetermined period before to the present. For example, recommended charge level generating unit 18 generates a regression line for the SOC during the target period and calculates the SOC slope. Setting the target period shorter allows for more recent trends to be reflected.

[0091] The recommended charge degree generating unit 18 assumes that the calculated SOC gradient continues and predicts the future SOC transition of the battery pack 50. The recommended charge degree generating unit 18 calculates the predicted transition of the recommended charge degree based on the predicted SOC transition of the battery pack 50.

[0092] Figure 7This is a diagram showing an example 1 of a time series display of the recommended charging level. The horizontal axis represents time, and the vertical axis represents the recommended charging level. The solid line L1 represents the change in the recommended charging level from a specified period ago to the present. The thick dashed line L2 represents the predicted change in the recommended charging level if the current slope of the SOC continues. The thin dashed line L3 represents the predicted change in the recommended charging level if the operation of the battery-mounted device 1 stops. When the operation of the battery-mounted device 1 stops, the thick dashed line L2 disappears and the thin dashed line L3 is displayed. In addition, when the slope of the SOC changes, the slope of the thick dashed line L2 changes. By observing the time series display of the recommended charging level, the user can identify the next time to charge.

[0093] Figure 8 This figure shows a second time-series display example of the recommended charging level. The horizontal axis represents travel distance, and the vertical axis represents the recommended charging level. This time-series display example 2 is for an EV equipped with battery 1. The recommended charging level generating unit 18 calculates the travel distance per unit SOC change based on the SOC change of the battery pack 50 during the target period from a predetermined period before to the present and the travel distance during the target period acquired from the vehicle's odometer. The recommended charging level generating unit 18 predicts future changes in the recommended charging level relative to travel distance based on the travel distance per unit SOC change and the predicted SOC change of the battery pack 50.

[0094] The recommended charging degree generation unit 18 may also cooperate with the vehicle's car navigation system to identify candidate charging stations adjacent to a recommended charging location, which is a distance from the current location that is equal to the driving distance required for the recommended charging degree to reach the recommended charging start line. The display control unit 19 may, for example, sequentially display three candidate charging stations adjacent to the recommended charging location in ascending order of distance. Furthermore, if there are no charging stations near the recommended charging location and there is a risk of battery failure if charging is not done in advance, the recommended charging line may be lowered to encourage early charging.

[0095] according to Figure 8 The time series display example 2 of the recommended charging degree shown above allows the user (driver) to intuitively identify the location where charging is required while driving, making it easier to make a driving plan. Figure 8 The time series display of the recommended charge level shown above makes it possible to infer which driving behavior affects how the remaining charge of the battery pack 50. That is, the time series display example of the recommended charge level also has the effect of prompting the user to change his or her driving behavior next time and thereafter.

[0096] Figure 9This is a flowchart showing the basic flow of the recommended charging level display process. The ideal SOC range calculation unit 16 calculates the ideal SOC range optimal for degradation suppression based on statistical data from battery data (S10). The recommended charging level generation unit 18 sets the lower limit SOC of the ideal SOC usage range as the recommended charging start value and the upper limit SOC as the recommended charging end value (S11).

[0097] The battery data acquisition unit 11 acquires current battery data (S12). The recommended charge level generation unit 18 calculates the recommended charge level based on the current SOC of the battery pack 50 (S13). The display control unit 19 causes the display unit 30 to display the recommended charge level, the recommended charge start value, and the recommended charge end value (S14). The process of steps S12 through S14 is repeated ("No" in S15) until the display of the recommended charge level ends ("Yes" in S15).

[0098] As described above, according to this embodiment, by displaying a charging recommendation level customized for each user, even if the user lacks knowledge about battery degradation, they can be naturally guided to perform charging that minimizes degradation. Specifically, the user's charging timing can be adjusted to the optimal timing for minimizing degradation. Displaying the charging recommendation level also helps bridge the gap between each user's perceived remaining battery level and their actual remaining battery level.

[0099] Furthermore, the user does not need to make complex settings to display the recommended charging level, placing little burden on the user. Furthermore, by adjusting the rate of change of the recommended charging level based on temperature, SOH, or the user's charging start / end history, it is possible to calculate a more optimal recommended charging level that reflects environmental conditions and individual user charging preferences.

[0100] While the present disclosure has been described above based on the embodiments, those skilled in the art will appreciate that the embodiments are merely illustrative and that various modifications are possible in the combinations of the various structural elements and processing steps, and that such modifications are also within the scope of the present disclosure.

[0101] In the above Figure 5 、 Figure 6 , an example was described in which the display control unit 19 displays the recommended charging level using a bar. In this regard, to reduce display space, the display control unit 19 may also display the recommended charging level using a numerical value. If the recommended charging level exceeds the recommended charge start value or falls below the recommended charge end value, the display control unit 19 may, for example, change the color of the numerical value to a more conspicuous color (e.g., red) or cause the numerical value to flash.

[0102] In the above embodiment, the display control unit 19 changes the speed at which the recommended charging level bar changes based on temperature, SOH, or the user's charging start / end history. Alternatively, the display control unit 19 may change the position of the recommended charging level bar line or the recommended charging level line instead of changing the speed at which the recommended charging level bar changes.

[0103] Furthermore, the audio notification unit (not shown) may output an alarm or audio message from a speaker within the vehicle cabin when the recommended charging level reaches the recommended charge start value or the recommended charge end value. Furthermore, if battery-mounted device 1 is an EV, the approaching sound control unit (not shown) may increase the volume or frequency of the approaching sound emitted from the vehicle speakers while the vehicle is driving as the recommended charging level approaches the recommended charge start value.

[0104] In the above embodiment, the battery-mounted device 1 uses an offline, independent configuration to generate a histogram, an ideal SOC range, and a recommended charging level. However, an online configuration can also be used to implement the degradation suppression system. In this case, the battery-mounted device 1 connects to a server via a network, and battery data is transmitted from the battery-mounted device 1 to the server. Based on the received battery data, the server generates a histogram, an ideal SOC range, and a recommended charging level. The server then transmits recommended charging start and end values ​​based on the ideal SOC range, as well as the recommended charging level, to the battery-mounted device 1.

[0105] In the case of an online structure, Figure 2 The battery data acquisition unit 11, histogram generation unit 13, actual SOC range calculation unit 14, actual charge and discharge pattern generation unit 15, ideal SOC range calculation unit 16, SOH estimation unit 17, and recommended charge level generation unit 18 are provided on the server side. The SOC estimation unit 12, display control unit 19, and charge and discharge control unit 110 are provided on the battery-mounted device 1 side.

[0106] As described above, when monitoring the actual usage of a user's battery pack 50 using a histogram, average charging time, and average charging interval, it is possible to integrate the histogram, average charging time, and average charging interval using a difference calculation. This reduces the amount of battery data stored and the amount of computation required. Therefore, the degradation suppression method of this embodiment does not require a high-performance processor and can be implemented at low cost even in an offline, standalone configuration.

[0107] Furthermore, the embodiment can also be determined by the following items.

[0108] [Project 1]

[0109] A degradation suppression system (10) is characterized by comprising:

[0110] A histogram generating unit (13) generates a histogram of the SOC (State of Charge) dwell time of the battery (50) based on the battery data;

[0111] an actual SOC range calculation unit (14) for determining an SOC range falling within a prescribed occurrence probability based on the histogram as an actual SOC use range;

[0112] a recommended SOC range calculation unit (16) for calculating a recommended SOC range that suppresses degradation compared to the actual SOC range based on the actual SOC range and a statistical charge and discharge pattern based on the battery data, with reference to degradation characteristics of the battery (50); and

[0113] A charge recommendation degree generating unit (18) generates a charge recommendation degree that increases or decreases according to the SOC of the battery (50), using the lower limit SOC of the recommended SOC usage range as a charge start recommendation value and the upper limit SOC of the recommended SOC usage range as a charge end recommendation value.

[0114] This makes it possible to generate an individual index presented to the user so that the user's charging timing approaches the charging timing most suitable for degradation suppression.

[0115] [Project 2]

[0116] The degradation suppression system (10) according to item 1 is characterized in that:

[0117] A display control unit (19) is further provided, and the display control unit (19) causes a display unit (30) to display at least one of the charge start recommendation value and the charge end recommendation value, and the charge recommendation degree.

[0118] This allows the user's charging timing to be naturally guided closer to the charging timing that is most suitable for degradation suppression.

[0119] [Item 3]

[0120] The degradation suppression system (10) according to item 2 is characterized in that

[0121] The display control unit (19) displays the recommended charging level by a bar that expands and contracts according to the SOC of the battery (50).

[0122] The display control unit (19) displays at least one of the charge start recommended value and the charge end recommended value in the form of scale at a predetermined position within the extension and contraction range of the bar.

[0123] According to this, by displaying the recommended charge completion value by stretching the bar, the user's charging timing can be brought closer to the charging timing that is most suitable for degradation suppression.

[0124] [Item 4]

[0125] The degradation suppression system (10) according to item 2 is characterized in that

[0126] The recommended charge level generating unit (18) predicts a future SOC change based on a SOC change of the battery (50) from a predetermined period before to the present, and predicts a future change in the recommended charge level.

[0127] The display control unit (19) displays the predicted transition of the recommended charging degree.

[0128] This allows the user to be presented with the optimal charging time or location in advance.

[0129] [Item 5]

[0130] The degradation suppression system (10) according to item 1 is characterized in that:

[0131] When the amount of degradation estimated based on the current temperature of the battery (50) and with reference to the charging degradation characteristics of the battery (50) when charging at the current temperature is greater than a threshold, the charging recommendation degree generating unit (18) slows down the rate of increase of the charging recommendation degree or subtracts an offset from the charging recommendation degree.

[0132] Based on this, a recommended charging level can be generated with reference to the temperature of the battery (50).

[0133] [Item 6]

[0134] The degradation suppression system (10) according to item 1 is characterized in that:

[0135] The lower the SOH (State Of Health) of the battery (50), the faster the change speed of the recommended charging level is made by the recommended charging level generation unit (18), or a larger offset is added to or subtracted from the recommended charging level.

[0136] Based on this, it is possible to generate a charge recommendation level with reference to the SOH of the battery (50).

[0137] [Item 7]

[0138] The degradation suppression system (10) according to item 1 is characterized in that:

[0139] The device further comprises a charging history storage unit (26) for storing a history of the SOC at the start of charging of the battery (50) by the user.

[0140] The recommended charge level generating unit (18) changes the speed of change of the recommended charge level or changes the offset added to or subtracted from the recommended charge level based on the difference between the statistical value of the SOC at the start of charging and the recommended charge level so as to reduce the difference.

[0141] This makes it possible to generate a charging recommendation level that takes into account the user's past tendency in charging start timing.

[0142] [Item 8]

[0143] The degradation suppression system (10) according to item 1 is characterized in that:

[0144] The device further comprises a charging history storage unit (26) for storing a history of the SOC at the end of charging of the battery (50) by the user.

[0145] The recommended charge level generating unit (18) changes the speed of change of the recommended charge level or changes the offset added to or subtracted from the recommended charge level based on the difference between the statistical value of the SOC at the end of charging and the recommended charge level so as to reduce the difference.

[0146] This makes it possible to generate a charging recommendation level that takes into account the user's past charging completion timing trends.

[0147] [Item 9]

[0148] A degradation suppression method, characterized by comprising the following steps:

[0149] Generating a histogram of the SOC (State Of Charge) dwell time of the battery (50) based on the battery data;

[0150] Determining, according to the histogram, an SOC range that falls within a specified probability of occurrence as an actual SOC usage range;

[0151] Calculating a recommended SOC usage range that suppresses degradation compared to the actual SOC usage range based on the actual SOC usage range and a statistical charge and discharge pattern based on the battery data, with reference to degradation characteristics of the battery (50); and

[0152] A charge recommendation degree is generated, which increases or decreases according to the SOC of the battery (50), using the lower limit SOC of the recommended SOC use range as a charge start recommendation value and the upper limit SOC of the recommended SOC use range as a charge end recommendation value.

[0153] This makes it possible to generate an individual index presented to the user so that the user's charging timing approaches the charging timing most suitable for degradation suppression.

[0154] [Item 10]

[0155] A degradation suppression program, characterized by causing a computer to execute the following processing:

[0156] Generating a histogram of the SOC (State Of Charge) dwell time of the battery (50) based on the battery data;

[0157] Determining, according to the histogram, an SOC range that falls within a specified probability of occurrence as an actual SOC usage range;

[0158] Calculating a recommended SOC usage range that suppresses degradation compared to the actual SOC usage range based on the actual SOC usage range and a statistical charge and discharge pattern based on the battery data, with reference to degradation characteristics of the battery (50); and

[0159] A charge recommendation degree is generated, which increases or decreases according to the SOC of the battery (50), using the lower limit SOC of the recommended SOC use range as a charge start recommendation value and the upper limit SOC of the recommended SOC use range as a charge end recommendation value.

[0160] This makes it possible to generate an individual index presented to the user so that the user's charging timing approaches the charging timing most suitable for degradation suppression.

[0161] Description of Reference Numerals

[0162] 1: Battery-mounted device; 2: Commercial power system; 3: AC adapter; 10: Control unit; 11: Battery data acquisition unit; 12: SOC estimation unit; 13: Histogram generation unit; 14: Actual SOC range calculation unit; 15: Actual charge and discharge pattern generation unit; 16: Ideal SOC range calculation unit; 17: SOH estimation unit; 18: Charging recommendation degree generation unit; 19: Display control unit; 110: Charge and discharge control unit; 20: Storage unit; 21: Battery data storage unit; 22: Histogram storage unit; 23: Charge degradation characteristic map; 24: Discharge degradation characteristic map; 25: Save degradation characteristic map; 26: Charge history record storage unit; 30: Display unit; 40: Operation unit; 50: Battery pack; 51: Voltage sensor; 52: Current sensor; 53: Temperature sensor; 60: Charging unit.

Claims

1. A degradation suppression system, characterized in that: have: a histogram generating unit for generating a histogram representing a retention time of a state of charge (SOC) of the battery based on the battery data; an actual SOC range calculation unit for determining, based on the histogram, an SOC range falling within a prescribed occurrence probability as an actual SOC usage range; a recommended SOC range calculation unit that calculates a recommended SOC range that suppresses degradation compared to the actual SOC range based on the actual SOC range and a statistical charge and discharge pattern based on the battery data, with reference to degradation characteristics of the battery; as well as A recommended charging degree generating unit generates a recommended charging degree that increases or decreases according to the SOC of the battery, using a lower limit SOC of the recommended SOC use range as a recommended charging start value and an upper limit SOC of the recommended SOC use range as a recommended charging end value.

2. The degradation suppression system according to claim 1, wherein: The device further includes a display control unit configured to cause a display unit to display at least one of the charge start recommended value and the charge end recommended value, and the charge recommendation degree.

3. The degradation suppression system according to claim 2, wherein: The display control unit displays the recommended charging level using a bar that expands and contracts according to the SOC of the battery. The display control unit displays at least one of the recommended charge start value and the recommended charge end value in the form of scale marks at a predetermined position within the extension / retraction range of the bar.

4. The degradation suppression system according to claim 2, wherein: The recommended charge level generating unit predicts a future SOC transition based on a SOC transition of the battery from a predetermined period before to the present, and predicts a future transition of the recommended charge level. The display control unit displays a predicted transition of the recommended charging level.

5. The degradation suppression system according to claim 1, wherein: When the degradation amount estimated based on the current temperature of the battery and with reference to the charging degradation characteristics of the battery when charging at the current temperature is greater than a threshold, the recommended charging degree generating unit slows down the rate of increase of the recommended charging degree or subtracts an offset from the recommended charging degree.

6. The degradation suppression system according to claim 1, wherein: The lower the SOH indicating the state of health of the battery is, the faster the speed of change of the recommended charging level is, or a larger offset is added to or subtracted from the recommended charging level is.

7. The degradation suppression system according to claim 1, wherein: The device further comprises a charging history storage unit for storing a history of the SOC of the battery at the start of charging by the user. The recommended charge level generating unit changes a change rate of the recommended charge level or changes an offset added to or subtracted from the recommended charge level based on a difference between the statistical value of the SOC at the start of charging and the recommended charge level to reduce the difference.

8. The degradation suppression system according to claim 1, wherein: The device further comprises a charging history storage unit for storing a history of the SOC at the time when charging of the battery by the user is completed. The recommended charge level generating unit changes a change rate of the recommended charge level or changes an offset added to or subtracted from the recommended charge level based on a difference between the statistical value of the SOC at the end of charging and the recommended charge level to reduce the difference.

9. A degradation suppression method, characterized in that: The following steps are involved: generating a histogram of the dwell time representing the state of charge (SOC) of the battery based on the battery data; Determining, according to the histogram, an SOC range that falls within a specified probability of occurrence as an actual SOC usage range; Calculating a recommended SOC usage range that suppresses degradation compared to the actual SOC usage range based on the actual SOC usage range and a statistical charge and discharge pattern based on the battery data, with reference to degradation characteristics of the battery; as well as A charge recommendation degree that increases or decreases according to the SOC of the battery is generated, with the lower limit SOC of the recommended SOC use range being used as a charge start recommended value and the upper limit SOC of the recommended SOC use range being used as a charge end recommended value.

10. A degradation suppression program, characterized in that: Causes the computer to perform the following processing: generating a histogram of the dwell time representing the state of charge (SOC) of the battery based on the battery data; Determining, according to the histogram, an SOC range that falls within a specified probability of occurrence as an actual SOC usage range; Calculating a recommended SOC usage range that suppresses degradation compared to the actual SOC usage range based on the actual SOC usage range and a statistical charge and discharge pattern based on the battery data, with reference to degradation characteristics of the battery; as well as A charge recommendation degree that increases or decreases according to the SOC of the battery is generated, with the lower limit SOC of the recommended SOC use range being used as a charge start recommended value and the upper limit SOC of the recommended SOC use range being used as a charge end recommended value.

11. A transient storage medium, characterized in that: A degradation suppression program executed by a computer according to claim 10 is described.

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