Battery capacity estimation device for secondary battery, battery capacity estimation method for secondary battery, and secondary battery charging device

Abstract

To grasp a battery capacity in the original process of use (in a process of charging electricity to and discharging electricity from a secondary battery) without performing operations only to grasp the battery capacity.SOLUTION: When an electric vehicle is in a traveling state, electric energy change derivation means 11 and remaining amount change derivation means 12 derive a change in electric energy (kWh) and a change in the remaining amount of a battery (%) from information from an on-vehicle device 3, and on the basis of the change in the remaining amount of the battery (%) relative to the change in electric energy (kWh), capacity estimation means 13 estimates the battery capacity (kWh) of the battery.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a battery capacity estimation device for a secondary battery, a battery capacity estimation method for a secondary battery, and a charging device for a secondary battery. [Background technology]

[0002] Secondary batteries are used as on-board batteries for electric vehicles (EVs) and as storage batteries for solar power generation equipment, wind power generation equipment, etc. For example, the on-board batteries of electric vehicles store electricity by charging from a charging facility, and supply power from the stored electricity to the drive source (motor).

[0003] For example, electric vehicles have the advantages of being environmentally friendly, highly efficient, and able to use electricity from a variety of sources, and so the current situation is that electric vehicles and rapid charging facilities are becoming more widespread.

[0004] When an electric vehicle is used for a long period of time, the on-board battery, which is a secondary battery, may deteriorate (battery capacity: battery capacity decreases), and there is a risk that the deterioration of the on-board battery (decrease in battery capacity) may affect the performance of the electric vehicle. For this reason, it is preferable to understand the deterioration (decrease in battery capacity) of secondary batteries, including the on-board battery.

[0005] For this reason, various techniques for grasping the deterioration of a secondary battery (technologies for grasping the battery capacity) have been proposed in the past (for example, see Patent Document 1). The techniques proposed in the past charge a discharged secondary battery in multiple stages and judge the deterioration (decrease in capacity) based on the time it takes to charge. Therefore, by grasping the capacity of the secondary battery, it is possible to judge the deterioration of the secondary battery and take measures to maintain the performance of the electric vehicle.

[0006] However, in conventional technology, because multi-stage charging is performed, work is required just to grasp the battery capacity, and in the case of an electric vehicle, it is difficult to perform the work while the on-board battery is installed. Therefore, in reality, it is difficult to sequentially determine the battery capacity in the actual usage state. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2013-57603 A Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a battery capacity estimation device for a secondary battery and a battery capacity estimation method for a secondary battery that can grasp the battery capacity during the actual usage process.

[0009] In addition, the present invention has been made in consideration of the above-mentioned situation, and aims to provide a charging device for a secondary battery that can grasp the battery capacity of a secondary battery being charged during the course of its intended use (the course of charging the secondary battery). [Means for solving the problem]

[0010] In order to achieve the above-mentioned object, the battery capacity estimation device for a secondary battery of the present invention according to claim 1 is characterized in that it comprises an electric energy change derivation means for deriving a change in electric energy (kWh) based on changes in the voltage and current of the secondary battery, a remaining amount change derivation means for deriving a change in remaining amount of power (%) based on changes in the voltage and current of the secondary battery, and a capacity estimation means for estimating the battery capacity (kWh) of the secondary battery based on the change in remaining amount of power (%) derived by the remaining amount change derivation means relative to the change in electric energy (kWh) derived by the electric energy change derivation means.

[0011] In the present invention according to claim 1, when the secondary battery is in operation, the battery capacity (kWh) of the secondary battery can be estimated by a capacity estimation means based on the change (%) in the remaining amount of power derived by the remaining amount change derivation means relative to the change (kWh) in the amount of power derived by the power amount change derivation means.

[0012] Specifically, the change in the remaining power (battery capacity) during operation of the secondary battery (change in charging rate: change in consumption) is calculated, and the battery capacity (kWh) of the secondary battery is estimated based on the change in the amount of power (kWh) corresponding to the change in consumption.

[0013] In other words, the battery capacity (kWh) of the secondary battery can be defined and estimated based on the following formula: Battery capacity (kWh)= {Change in power consumption (kWh) / Change in remaining power (%)} x 100 (%)

[0014] This eliminates the need to perform an operation solely to ascertain the battery capacity, and makes it possible to ascertain the battery capacity during the actual usage process (the process of charging and discharging the secondary battery), and also makes it possible to check the absolute value of the battery capacity successively.

[0015] The secondary battery capacity estimation device of the present invention according to claim 2 is characterized in that, in the secondary battery capacity estimation device according to claim 1, the power amount change deriving means and the remaining charge change deriving means derive the change in power amount (kWh) and the change in remaining charge (%) based on changes in voltage and current during charging of the secondary battery.

[0016] In the present invention according to claim 2, the battery capacity (kWh) of the secondary battery can be estimated based on the changes in voltage and current during charging of the secondary battery (based on data during charging).

[0017] Furthermore, the battery capacity estimation device for a secondary battery of the present invention according to claim 3 is characterized in that, in the battery capacity estimation device for a secondary battery described in claim 2, the power amount change deriving means and the remaining charge change deriving means derive the change in power amount (kWh) and the change in remaining charge (%) while further including changes in voltage and current during discharge of the secondary battery.

[0018] In the present invention according to claim 3, the battery capacity (kWh) of the secondary battery can be estimated based on the changes in voltage and current during charging and discharging of the secondary battery (based on data during charging and discharging).

[0019] In addition, the battery capacity estimation device for a secondary battery of the present invention as set forth in claim 4 is characterized in that, in the battery capacity estimation device for a secondary battery as set forth in claim 3, the capacity estimation means derives battery capacity (kWh) based on the portion where the value of the change (%) in the remaining power changes from a decrease to an increase, using as a reference the value at which the change (%) in the remaining power changes from a decrease to an increase.

[0020] In the present invention according to claim 4, the battery capacity (kWh) of the secondary battery can be estimated based on the change in the discharge state, using the value at which the change in the remaining amount of power (%) changes from decreasing to increasing as a reference, i.e., the bottom value of the change in the remaining amount of power (%) where the value is decreasing.

[0021] In addition, the battery capacity estimation device for a secondary battery of the present invention as set forth in claim 5 is characterized in that, in the battery capacity estimation device for a secondary battery as set forth in claim 3, the capacity estimation means derives battery capacity (kWh) based on the portion where the value of the change (%) in the remaining power changes from a decrease to an increase, using as a reference the value at which the change (%) in the remaining power changes from a decrease to an increase.

[0022] In the present invention according to claim 5, the battery capacity (kWh) of the secondary battery can be estimated based on the change in the charging state, using the value at which the change in the remaining amount of power (%) changes from a decrease to an increase as a reference, i.e., the portion where the value of the change in the remaining amount of power (%) is increasing, i.e., the bottom value of the change in the remaining amount of power (%).

[0023] In addition, the battery capacity estimation device for a secondary battery of the present invention as claimed in claim 6 is characterized in that, in the battery capacity estimation device for a secondary battery as described in claim 3, the capacity estimation means derives battery capacity (kWh) based on the increasing and / or decreasing portion of the change in the remaining power amount (%) when the change in the remaining power amount (%) changes from a decrease to an increase and becomes equal to or greater than a predetermined threshold value, using as a reference the value at which the change in the remaining power amount (%) changes from a decrease to an increase.

[0024] In the present invention according to claim 6, when the value of the change (%) in the remaining amount of power changes to a predetermined threshold value or more (when there is a change of a predetermined value or more) based on the value at which the change (%) in the remaining amount of power changes from a decrease to an increase, the battery capacity (kWh) of the secondary battery can be estimated based on the change in the charging state and / or discharging state using the increasing or / and decreasing part of the change (%) in the remaining amount of power, i.e., the bottom value of the change (%) in the remaining amount of power as the reference. In other words, since the battery capacity (kWh) is estimated using the part of the secondary battery where the change (%) in the remaining amount of power is large, the battery capacity (KWh) can be obtained with reduced error.

[0025] Furthermore, the battery capacity estimation device for a secondary battery of the present invention according to claim 7 is characterized in that, in the battery capacity estimation device for a secondary battery according to any one of claims 1 to 6, the secondary battery is an on-board battery mounted in an electric vehicle, the electric energy change deriving means and the remaining amount change deriving means derive the change in remaining amount of power (%) and the change in electric energy (kWh) based on information from on-board equipment of the electric vehicle when the electric vehicle is in a traveling state, and the capacity estimation means estimates the battery capacity of the on-board battery as the battery capacity (kWh) of the secondary battery.

[0026] In the present invention according to claim 7, the battery capacity of the on-board battery can be estimated when the electric vehicle is in a running state {for example, a series of states such as running, stopping, and parking in a predetermined unit (half a day, one day, three days, etc.)}, that is, during the actual course of use, without performing a task solely for estimating the battery capacity.

[0027] In order to achieve the above-mentioned object, the battery capacity estimation method for a secondary battery of the present invention according to claim 8 is characterized in that it calculates the change in electric energy (kWh) and the change in remaining power (%) based on changes in the voltage and current of a secondary battery during operation, and estimates the battery capacity (kWh) of the secondary battery based on the change in the remaining power (%) relative to the change in electric energy (kWh).

[0028] In the present invention according to claim 8, the battery capacity (kWh) of the secondary battery can be estimated based on the change (%) in the remaining amount of power relative to the change (kWh) in the amount of power when the secondary battery is in operation. Specifically, the change (change in the charging rate: change in consumption) in the remaining amount of power (remaining battery amount) during operation of the secondary battery is calculated, and the battery capacity (kWh) of the secondary battery is estimated based on the change (kWh) in the amount of power corresponding to the change in consumption.

[0029] In other words, the battery capacity (kWh) of the secondary battery can be defined and estimated based on the following formula: Battery capacity (kWh)= {Change in power consumption (kWh) / Change in remaining power (%)} x 100 (%)

[0030] This makes it possible to know the battery capacity during actual use without having to perform the task of simply estimating the battery capacity.

[0031] In order to achieve the above-mentioned object, the secondary battery charging device of the present invention according to claim 9 is a secondary battery charging device for charging a secondary battery, and is characterized in that it comprises an electric energy change derivation means for deriving a change in electric energy (kWh) based on changes in the voltage and current of the secondary battery during charging, a remaining amount change derivation means for deriving a change in remaining amount of power (%) based on changes in the voltage and current of the secondary battery during charging, and a capacity estimation means for estimating a battery capacity (kWh) of the secondary battery based on the change in remaining amount of power (%) derived by the remaining amount change derivation means relative to the change in electric energy (kWh) derived by the electric energy change derivation means.

[0032] In the present invention according to claim 9, when the secondary battery is being charged, the battery capacity (kWh) of the secondary battery can be estimated by a capacity estimation means based on the change (%) in the remaining amount of power derived by the remaining amount change derivation means relative to the change in the amount of power (kWh) derived by the power amount change derivation means.

[0033] Specifically, the change in remaining power (battery capacity) while the secondary battery is being charged (the increase in the amount of power during charging) is calculated, and the battery capacity (kWh) of the secondary battery is estimated based on the change in the amount of power (kWh) corresponding to this increase.For example, if the change in the charging power is greater than the same change in the amount of power (integrated value: a negative value because the current is negative during charging), it can be estimated that the battery capacity is decreasing.

[0034] In other words, the battery capacity (kWh) of a secondary battery can be estimated by defining it as follows: Battery capacity (kWh)= {Change in power consumption (kWh) / Change in remaining power (%)} x 100 (%)

[0035] Therefore, during the process of charging the secondary battery (the process of its intended use), it becomes possible to grasp the battery capacity of the secondary battery being charged by the charging device. Effect of the Invention

[0036] The secondary battery capacity estimation device and secondary battery capacity estimation method of the present invention make it possible to grasp the battery capacity during the actual use process.

[0037] The secondary battery charging device of the present invention makes it possible to grasp the battery capacity of the secondary battery being charged during the course of its intended use. [Brief description of the drawings]

[0038] [Figure 1] 1 is a schematic diagram illustrating the concept of a battery capacity estimation device for a secondary battery according to the present invention. [Diagram 2] FIG. 2 is a block diagram of a control means. [Diagram 3] FIG. 1 is a diagram illustrating the change in remaining battery capacity (%) and power consumption (kWh) over one day. [Figure 4] FIG. 1 is a diagram for explaining the change in battery capacity over a predetermined number of days (for example, 365 days). [Diagram 5] FIG. 11 is a diagram illustrating another example of the change over time in the remaining battery charge (%) and the amount of power (kWh) in one day. [Figure 6] 1 is a schematic diagram illustrating the concept of a charging device for a secondary battery according to an embodiment of the present invention. [Figure 7] FIG. 2 is a diagram illustrating the change over time in the battery charge amount (%) and the amount of power (kWh) per charge. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0039] The battery capacity estimation device for a secondary battery of the present invention will be described with reference to Figures 1 to 4. As a specific example of the battery capacity estimation device for a secondary battery, a case will be described in which the device is applied to estimation of the battery capacity of a battery in an electric vehicle (e.g., a commercial vehicle such as a taxi or hire car).

[0040] FIG. 1 shows an overall conceptual diagram for explaining a battery capacity estimation device for a secondary battery according to one embodiment of the present invention, FIG. 2 shows a block diagram for explaining the function of the control means, FIG. 3 shows the change in the remaining battery charge (%) and the amount of power (kWh) over one day, and FIG. 4 shows the change in the battery capacity (kWh) over a specified number of days (e.g., 365 days).

[0041] As shown in Fig. 1, an electric vehicle 1 is equipped with a battery 2 as a secondary battery. The voltage (V), current (A), and remaining battery capacity (%) of the battery 2 are monitored by an in-vehicle device 3. The information on the voltage (V), current (A), and remaining battery capacity (%) of the battery 2 monitored by the in-vehicle device 3 is sent to a control means 4 on the cloud.

[0042] 2, the control means 4 has power amount change deriving means 11 that derives the change in power amount (kWh: for example, an integrated value per second) based on the changes in the voltage (V) and current (A) of the battery 2. The control means 4 also has remaining amount change deriving means 12 that derives the change in remaining battery amount (%), which is the change in the remaining amount of power, based on the changes in the voltage (V) and current (A) of the battery 2.

[0043] The control means 4 has a capacity estimation means 13 which estimates the battery capacity (kWh) of the battery 2 based on the change (%) in the remaining battery charge derived by the remaining charge change derivation means 12 relative to the change in the amount of power (kWh) derived by the power amount change derivation means 11.

[0044] In the capacity estimation means 13, when the electric vehicle 1 is in a traveling state (when the secondary battery is in operation), the battery capacity (kWh) of the battery 2 is estimated based on the change (%) in the remaining battery charge relative to the change (kWh) in the amount of electric power.

[0045] The electric vehicle 1 being in a running state refers to a series of states such as running, stopping, and being parked in a predetermined unit (half a day, one day, three days, etc.), for example.

[0046] As a result, there is no need to perform the task of simply determining the battery capacity, and it is possible to determine the battery capacity (kWh) of Battery 2 during the driving state, which is the process of its intended use (the process of charging and discharging Battery 2).

[0047] The battery capacity (kWh) of the battery 2 grasped by the control means 4 is stored and accumulated in the cloud as data for each electric vehicle 1. As shown in Fig. 1, the data stored in the cloud is sent to a management company 5 such as a taxi or hire car office or management department. The management company 5 manages the deterioration state of the battery 2 for each electric vehicle 1, and uses the data for vehicle management of multiple electric vehicles 1 as maintenance data for vehicle inspections and maintenance.

[0048] In addition, the data stored on the cloud is sent to a portable device (smartphone) 6 of the driver or the like, enabling the driver or the like to check the deterioration status of the battery 2 of the electric vehicle 1 while they are riding.

[0049] The estimation of the battery capacity (kWh) will be specifically described with reference to FIG. 3 and FIG.

[0050] As shown in Figure 3, the in-vehicle device 3 (see Figure 1) records the relationship between the change (in percent) in the remaining battery charge (per day) from the time t1 when the driving starts to the time te when the driving ends, and the change in the amount of power (kWh).

[0051] As shown by the thin solid line in the figure, when the battery remaining charge at time te is 58%, the change in the battery remaining charge is 42%. As shown by the thick solid line in the figure, the change (kWh) in the amount of power required (consumed) for driving at time te is 42 (kWh).

[0052] As shown by the thin solid line in the figure, charging starts at time te, and the remaining battery capacity is 100% at time td (fully charged state). During charging, the current value is negative, so the change in the amount of power (kWh) is 0 (kWh) at time td, as shown by the thick solid line.

[0053] The capacity estimation means 13 (see FIG. 2) estimates the battery capacity (kWh) of the battery 2 based on the change (%) in the remaining battery charge relative to the change (kWh) in the amount of power.

[0054] For example, if the change in the amount of electricity (kWh) is 42 (kWh) as shown by the thick solid line in the figure, and the change in the remaining battery charge is 42% as shown by the thin solid line in the figure, the battery capacity (kWh) of Battery 2 is estimated to be 100%.

[0055] In other words, the battery capacity (kWh) of battery 2 can be defined and estimated based on the following formula: Battery capacity (kWh) = {Change in power consumption (kWh) / Change in remaining battery power (%)} x 100 (%)

[0056] As shown by the thick solid line in the figure, when the change in the remaining battery charge is large (for example, 50%) for the same change in the amount of power (accumulated value: 42 kWh), as shown by the dotted line in the figure, applying the above formula, it is estimated that the battery capacity (kWh) of Battery 2 (see Figure 1) will be 84% (decreased).

[0057] In other words, the change in the remaining power of battery 2 (see Figure 1) while electric vehicle 1 (see Figure 1) is running (while the secondary battery is in operation), i.e., the change in remaining battery power (change in charging rate: change in consumption) is calculated (remaining power change deriving means 12: see Figure 2), and the battery capacity (kWh) of battery 2 is estimated (capacity estimation means 13: see Figure 2) based on the change in the amount of power (kWh) corresponding to the change in consumption (power amount change deriving means 11: see Figure 2).

[0058] When estimating the battery capacity (kWh) of the battery 2 (see FIG. 1), the change in the amount of power (kWh) based on the change in voltage and current during discharging from time t1 to time te, and the change in the remaining battery capacity (%) can be applied. Also, the change in the amount of power (kWh) based on the change in voltage and current during charging from time te to time td, and the change in the remaining battery capacity (%) can be applied. Furthermore, the change in the amount of power (kWh) based on the change in voltage and current during discharging and charging from time t1 to time td, and the change in the remaining battery capacity (%) can be applied.

[0059] Data on the battery capacity (kWh) for a given unit (e.g., one day) while the electric vehicle 1 (see FIG. 1) is in a running state is accumulated on the cloud. As shown in FIG. 4, data on the battery capacity (kWh) for, for example, 300 days or more (e.g., 365 days) is accumulated. By accumulating data over a long period of time, it is possible to grasp the decreasing trend of the battery capacity (kWh) of the battery 2 (the downward trend to the right in the figure).

[0060] That is, even if there is variation in the daily battery capacity (kWh) values ​​(individual data), it is possible to grasp the tendency of the battery capacity (kWh) of battery 2 decreasing over the entire 365-day period, for example.

[0061] Another example of the driving pattern will be described with reference to FIG.

[0062] Figure 5 shows another example of the change in battery remaining capacity (%) and power consumption (kWh) over a day.

[0063] As shown by the thin solid line in the figure, the vehicle travels from time t1, when the vehicle starts, to time t2, and the remaining charge of Battery 2 (see Figure 1) decreases. After that, charging begins at time t2, and at time t3, the remaining charge of Battery 2 (see Figure 1) becomes 100% (fully charged state). The vehicle resumes traveling at time t4, and the remaining charge of Battery 2 (see Figure 1) decreases until the vehicle ends traveling at time te. The change in the amount of electric power (KWh) at this time is as shown by the thick solid line in the figure.

[0064] As shown by the thin solid line, charging starts at time te, and the remaining battery capacity reaches 100% (fully charged state) at time td. Based on the change (%) in the remaining battery capacity relative to the change (kWh) in the amount of power, shown by the thick solid line in the figure, the battery capacity (kWh) of the battery 2 (see FIG. 1) is estimated (capacity estimation means 13: see FIG. 2).

[0065] In the state of Fig. 5, as shown by the thin solid line in the figure, at time t2, the change (%) in the remaining battery capacity changes from a decrease to an increase, and at time te, as shown by the thin solid line in the figure, the change (%) in the remaining battery capacity changes from a decrease to an increase.

[0066] In this case, the battery capacity (kWh) can be derived based on the portion of the change (%) in the remaining battery charge that is decreasing (the corresponding change in the amount of power) using times t2 and te as the reference (the value at which the change (%) in the remaining battery charge changes from a decrease to an increase).

[0067] In addition, the battery capacity (kWh) can be derived based on the portion where the change in the battery remaining capacity (%) is increasing (the corresponding change in the amount of power) using times t2 and te as a reference (the value at which the change in the battery remaining capacity (%) changes from a decrease to an increase as a reference).

[0068] That is, the battery capacity (kWh) of the battery 2 can be estimated based on the change in the discharged state and the charged state, with the bottom value of the change (%) of the remaining battery charge being used as a reference.

[0069] On the other hand, when the change in the battery remaining capacity (%) changes to or exceeds a predetermined threshold value (e.g., 25% or more) based on time t2 or time te (based on the value at which the change in the battery remaining capacity (%) changes from a decrease to an increase), the battery capacity (kWh) is derived based on the increasing and / or decreasing portion of the change in the battery remaining capacity (%) (the corresponding change in the amount of power).

[0070] In the example of Fig. 5, as shown by the thin solid line in the figure, the change (%) in the remaining battery capacity in the portion based on time t2 is about 20%, which is less than a predetermined threshold (e.g., less than 25%). As shown by the thin solid line in the figure, the change (%) in the remaining battery capacity in the portion based on time te is about 40%, which is greater than or equal to a predetermined threshold (e.g., greater than or equal to 25%).

[0071] Therefore, since the change (%) in the remaining battery charge based on time te has changed to or above a predetermined threshold value (e.g., 25% or more), the battery capacity (kWh) is derived based on the increasing and / or decreasing portion (the corresponding change in the amount of power) of the change (%) in the remaining battery charge based on time te.

[0072] Since the battery capacity (kWh) is derived based on the change (%) in the battery remaining capacity where the change (%) is equal to or greater than a predetermined threshold (e.g., 25% or more), it is possible to derive the battery capacity (kWh) with reduced error by eliminating small changes in the battery remaining capacity. In other words, the battery capacity (kWh) is estimated using the portion where the change (%) in the battery remaining capacity is large, so it is possible to determine the battery capacity (kWh) with reduced error.

[0073] The above-mentioned secondary battery capacity estimation device calculates the change in electric energy (kWh) and the change in remaining battery charge (%) based on the changes in voltage and current of the battery 2 of the electric vehicle 1 in a running state, and estimates the battery capacity (kWh) of the battery 2 based on the change in remaining battery charge (%) relative to the change in electric energy (kWh).

[0074] Therefore, while the electric vehicle 1 is running (in a running state), the battery capacity (kWh) of the battery 2 can be estimated, and there is no need to perform an operation simply to grasp the battery capacity (kWh).

[0075] A charging device for a secondary battery according to the present invention will be described with reference to Figures 6 and 7. A quick charging device for quick charging an electric vehicle 1 will be taken as an example of the charging device.

[0076] FIG. 6 shows the overall concept for explaining a secondary battery charging device according to one embodiment of the present invention, and FIG. 7 shows the change over time in the remaining battery capacity (%) and the amount of power (kWh) during one charge.

[0077] As shown in Fig. 6, quick charging device 16 is provided with a charging connector 17 that is connected to electric vehicle 1 to charge battery 2. Data obtained when charging battery 2 (see Fig. 1) with charging connector 17 connected, i.e., data on voltage (V) and current (A), is managed by quick charging device 16.

[0078] The quick charging device 16 is equipped with an electric energy change derivation means for deriving a change in electric energy (kWh) based on changes in voltage (V) and current (A), a remaining charge change derivation means for deriving a change in remaining battery charge (%), which is the change in the remaining amount of electric power, based on changes in the voltage (V) and current (A) of the battery 2, and a capacity estimation means for estimating a battery capacity (kWh), which is the battery capacity of the battery 2, based on the change in remaining battery charge (%) derived by the remaining charge change derivation means relative to the change in electric energy (kWh) derived by the electric energy change derivation means.

[0079] While the charging connector 17 is connected to the electric vehicle 1 and the battery 2 is being charged (while the secondary battery is in operation), the battery capacity (kWh) of the battery 2 is estimated based on the change (%) in the remaining battery charge relative to the change in the amount of power (kWh).

[0080] The information on the estimated battery capacity (kWh) of the battery 2 is displayed on the display unit 18 of the quick charging device 16, allowing the occupant to check the battery capacity (kWh) on the spot. In addition, the information on the estimated battery capacity (kWh) of the battery 2 is stored in the cloud, and can also be displayed on a mobile terminal or the like as necessary. When the battery 2 is being charged, the battery capacity (kWh) of the battery 2 can be estimated based on the change (%) in the remaining battery charge relative to the change in the amount of power (kWh).

[0081] The estimation of the battery capacity (kWh) will be specifically described with reference to FIG.

[0082] As shown in FIG. 7, the rapid charging device 16 records the relationship between the change in remaining battery capacity (%) and the change in the amount of power (kWh) from time t1 when charging starts to time te when charging ends.

[0083] As shown by the thin solid line in the figure, if the remaining battery charge at time te is 100% (fully charged), the change in the remaining charge of Battery 2, that is, the change in the remaining battery charge, is -100% (this is the percentage of the remaining charge, but for convenience, we will assume it to be -100). As shown by the thick solid line in the figure, the change in the amount of power (kWh) (a negative value because the current is negative during charging) is -100 (kWh).

[0084] For example, if the change in the amount of electricity (kWh) is -100 (kWh), as shown by the thick solid line in the figure, and the change in the remaining battery charge is -100%, as shown by the thin solid line in the figure, the battery capacity (kWh) of Battery 2 is estimated to be 100%.

[0085] In other words, the battery capacity (kWh) of battery 2 can be estimated by defining it as follows: Battery capacity (kWh) = {Change in power consumption (kWh) / Change in remaining battery capacity (%)} x 100 (%)

[0086] For example, as shown by the thin dotted line in the figure, if the remaining battery charge becomes 100% (fully charged) at time t2 before time te, the change in the amount of power (integrated value: for example, -80 kWh) will be as shown by the thick dotted line in the figure. In this case, the battery capacity (kWh) of battery 2 is estimated to be 80% according to the above formula.

[0087] Therefore, during the process of charging the battery 2 (during the process of intended use), it becomes possible to know the battery capacity of the battery 2 being charged by the quick charger 16. Since the battery capacity of the battery 2 being charged can be known by the quick charger 16, the battery capacity can be checked on the spot even if the electric vehicle 1 does not have a battery capacity meter. [Industrial Applicability]

[0088] The present invention can be utilized in the industrial fields of a battery capacity estimation device for a secondary battery, a battery capacity estimation method for a secondary battery, and a charging device for a secondary battery. [Explanation of symbols]

[0089] 1. Electric vehicles 2 Battery 3 In-vehicle equipment 4. Control Measures 5. Management Company 6 Mobile devices (smartphones) 11 Means of deriving change in power amount 12 Means for deriving remaining amount change 13 Capacity estimation means 16 Quick charging device 17 Charging connector 18 Display

Claims

1. an electric power amount change deriving means for deriving an amount of change in electric power (kWh) based on changes in the voltage and current of the secondary battery; a remaining amount change deriving means for deriving a change (%) in a remaining amount of power based on a change in a voltage and a current of the secondary battery; and a capacity estimation means for estimating a battery capacity (kWh) of the secondary battery based on a change (%) in the remaining amount of power derived by the remaining amount change deriving means relative to a change (kWh) in the amount of power derived by the power amount change deriving means. A battery capacity estimation device for a secondary battery.

2. 2. The battery capacity estimation device for a secondary battery according to claim 1, The power amount change deriving means and the remaining amount change deriving means Derive the change in the amount of power (kWh) and the change in the remaining amount of power (%) based on the changes in the voltage and current during charging of the secondary battery. A battery capacity estimation device for a secondary battery.

3. 3. The battery capacity estimation device for a secondary battery according to claim 2, The power amount change deriving means and the remaining amount change deriving means The change in the amount of electric power (kWh) and the change in the remaining amount of electric power (%) are derived while further including the changes in the voltage and current during the discharge of the secondary battery. A battery capacity estimation device for a secondary battery.

4. 4. The battery capacity estimation device for a secondary battery according to claim 3, The capacity estimation means includes: Using the value at which the remaining amount of power change (%) changes from a decrease to an increase as a reference, the battery capacity (kWh) is derived based on the portion at which the remaining amount of power change (%) decreases. A battery capacity estimation device for a secondary battery.

5. 4. The battery capacity estimation device for a secondary battery according to claim 3, The capacity estimation means includes: The battery capacity (kWh) is derived based on the portion where the value of the change (%) in the remaining amount of power increases, using the value where the change (%) in the remaining amount of power changes from a decrease to an increase as a reference. A battery capacity estimation device for a secondary battery.

6. 4. The battery capacity estimation device for a secondary battery according to claim 3, The capacity estimation means includes: When the value of the change (%) in the remaining amount of power changes to a predetermined threshold value or more, the battery capacity (kWh) is derived based on the increase and / or decrease in the value of the change (%) in the remaining amount of power, based on the value at which the change (%) in the remaining amount of power changes from a decrease to an increase. A battery capacity estimation device for a secondary battery.

7. 7. The battery capacity estimation device for a secondary battery according to claim 1, The secondary battery is An on-board battery installed in an electric vehicle. The power amount change deriving means and the remaining amount change deriving means deriving a change in the remaining amount of power (%) and a change in the amount of power (kWh) based on information from an on-board device of the electric vehicle while the electric vehicle is traveling; The capacity estimation means includes: The battery capacity of the vehicle battery is estimated as the battery capacity (kWh) of the secondary battery. A battery capacity estimation device for a secondary battery.

8. The change in the amount of electric power (kWh) and the change in the remaining amount of electric power (%) are calculated based on the changes in the voltage and current of the secondary battery during operation, and the battery capacity (kWh) of the secondary battery is estimated based on the change in the remaining amount of electric power (%) relative to the change in the amount of electric power (kWh). A method for estimating battery capacity of a secondary battery.

9. A secondary battery charging device for charging a secondary battery, comprising: an electric power amount change deriving means for deriving an amount of change in electric power (kWh) based on changes in voltage and current of the secondary battery during charging; a remaining capacity change amount deriving means for deriving a change amount (%) of a remaining capacity of the power based on a change in a voltage and a current of the secondary battery during charging; and a capacity estimation means for estimating a battery capacity (kWh) of the secondary battery based on a change (%) in the remaining amount of power derived by the remaining amount change deriving means relative to a change (kWh) in the amount of power derived by the power amount change deriving means. A charging device for a secondary battery.

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