Estimation system and vehicle

Abstract

To achieve both of suppression of deterioration of a power storage device and improvement of estimation accuracy of full charge capacity.SOLUTION: An estimation system 2 includes: a battery 10; and an ECU 100. The ECU 100 is configured to execute charge processing for charging the battery 10 and estimation processing for estimating full charge capacity of the battery 10. The charge processing includes limit charge processing for charging the battery 10 so that SOC of the battery 10 does not exceed upper limit SOC lower than full charge SOC of the battery 10. The ECU 100 executes first processing or second processing when a condition indicating lowering of estimation accuracy of the full charge capacity is established and executes limit charge processing when the condition is not established. The first processing includes processing for executing the charge processing by raising the upper limit SOC set in the limit charge processing more than that when the condition is not established. The second processing includes processing for executing the charge processing without executing the limit charge processing.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to an estimation system that estimates a full charge capacity of a power storage device and a vehicle equipped with the same. [Background technology]

[0002] Japanese Patent Laid-Open Publication No. 2017-195681 (Patent Document 1) discloses a capacity measurement device for an in-vehicle battery. This capacity measurement device calculates the full charge capacity of a battery by calculating an integrated value (charge amount) of a charging current when a battery in an empty state is charged to a fully charged state. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-195681 A Summary of the Invention [Problem to be solved by the invention]

[0004] Even if the power storage device is not charged from an empty state to a fully charged state, the full charge capacity of the power storage device can be estimated. For example, a method is known in which the full charge capacity is estimated by dividing the charge amount of the power storage device by the increment (ΔSOC) of the SOC (State Of Charge: the amount of charge relative to the fully charged state expressed as 0 to 100%) of the power storage device due to charging of the power storage device. When this method is used, the greater the ΔSOC, the higher the accuracy of estimating the full charge capacity. On the other hand, when the ΔSOC is large enough that the power storage device is charged to the fully charged state, the power storage device is in a highly charged state, which makes it more likely to deteriorate.

[0005] In recent years, the capacity of the power storage device has been increasing. When the capacity of the power storage device increases, it is sometimes preferred that the power storage device is not charged to a fully charged state in order to suppress deterioration of the power storage device. For example, an upper limit SOC lower than the fully charged SOC is set, and the power storage device is charged so that the SOC does not exceed the upper limit SOC. When the power storage device is not charged to a fully charged state, there are many cases in which the ΔSOC associated with charging is smaller than when the power storage device is charged to a fully charged state. As a result, the accuracy of the full charge capacity estimated using the above method may decrease.

[0006] The present disclosure has been made to solve the above problems, and its purpose is to provide an estimation system and a vehicle that can simultaneously suppress deterioration of a power storage device and improve the accuracy of estimating the full charge capacity. [Means for solving the problem]

[0007] The estimation system of the present disclosure includes a power storage device and a processing device. The processing device is configured to execute a charging process for charging the power storage device and an estimation process for estimating a full charge capacity of the power storage device. The charging process includes a limited charging process for charging the power storage device so that the SOC of the power storage device does not exceed an upper limit SOC lower than the full charge SOC of the power storage device. The estimation process includes a process for estimating a full charge capacity by dividing a charge amount charged to the power storage device by ΔSOC indicating an increment of SOC by the charging process. The processing device executes a first process or a second process when a condition indicating a decrease in the estimation accuracy of the full charge capacity is satisfied, and executes a limited charging process when the above condition is not satisfied. The first process includes a process for executing a charging process by raising an upper limit SOC set in the limited charging process to a value higher than when the condition is not satisfied. The second process includes a process for executing a charging process without executing a limited charging process.

[0008] With the above configuration, when the condition is not satisfied, the limited charging process is executed, and the power storage device is not charged to a fully charged state. As a result, deterioration of the power storage device is suppressed. On the other hand, when the condition is satisfied, the charging process is executed with the upper limit SOC raised, or the charging process is executed without executing the limited charging process (i.e., with the upper limit SOC not set). This increases ΔSOC more than when the condition is not satisfied. As a result, the error in the estimation result of the full charge capacity is reduced. Therefore, it is possible to achieve both suppression of deterioration of the power storage device and improvement of the estimation accuracy of the full charge capacity.

[0009] When the upper limit SOC is set by the user, the processing device may execute the first process or the second process.

[0010] With the above configuration, the first process or the second process is executed while allowing the user to set the upper limit SOC, thereby improving the accuracy of estimating the full charge capacity while improving the convenience for the user.

[0011] The above conditions may include a condition that a state in which the upper limit SOC is set by the user continues for a threshold time or longer.

[0012] The longer the state in which the upper limit SOC is set by the user continues, the longer the time the power storage device is not fully charged. Therefore, the likelihood that the estimation process will be executed in a state in which ΔSOC is small increases. As a result, the accuracy of estimating the full charge capacity may decrease. With the above configuration, the limited charging process can be executed until the state in which the upper limit SOC is set by the user continues for a threshold time or more. On the other hand, if this state continues for a threshold time or more, the first process or the second process is executed. As a result, the first process or the second process can be executed at an appropriate timing.

[0013] The above condition may include a condition that the limited charging process is executed consecutively a threshold number of times or more.

[0014] The more the number of times the limited charging process is executed in succession, the longer the time the power storage device is not fully charged. Therefore, the more likely it is that the estimation process will be executed when ΔSOC is small. As a result, the accuracy of estimating the full charge capacity may decrease. With the above configuration, when the limited charging process is executed in succession a threshold number of times or more, the first process or the second process is executed. As a result, the first process or the second process can be executed at an appropriate timing.

[0015] The processing device may further execute a notification process for notifying the user that the first process or the second process is to be executed.

[0016] With the above configuration, the user is notified that the first process or the second process is to be executed, thereby improving user convenience.

[0017] The processing device may further execute a reduction notification process for notifying a user to reduce the SOC at the start of charging the power storage device when the first process is executed.

[0018] The above configuration provides a user with an incentive to lower the SOC at the start of charging the power storage device, thereby making it possible to increase ΔSOC.

[0019] The charging process may include a reference charging process for charging the power storage device in a state in which the SOC at the end of charging of the power storage device is higher than a first reference value and the SOC at the start of charging of the power storage device is lower than a second reference value that is less than the first reference value. The above condition may include a condition that a state in which the reference charging process is not executed continues for a threshold duration or more from the end time of the reference charging process.

[0020] When the above state continues for a threshold duration or more, it is considered that the state in which the power storage device is not sufficiently charged continues for a long period of time. With the above configuration, it is possible to execute the limited charging process until this state continues for the threshold duration or more. On the other hand, when the above state continues for the threshold duration or more, the first process or the second process is executed. As a result, it is possible to execute the first process or the second process at an appropriate timing.

[0021] The threshold duration may be shorter as the time that has elapsed since the start of use of the power storage device is shorter. The full charge capacity of the power storage device is more likely to change (decrease) the shorter the time that has elapsed since the start of use of the power storage device. With the above configuration, the threshold duration becomes shorter the longer the period during which the full charge capacity is more likely to change, making it easier to execute the first process or the second process. As a result, the frequency of the first process or the second process is increased. Therefore, the frequency with which the full charge capacity estimation process is appropriately executed can be increased.

[0022] The estimation accuracy may be determined according to the SOC at the start of charging the power storage device and the SOC at the end of charging the power storage device. The above conditions may include a condition under which the estimation accuracy is equal to or less than a threshold accuracy.

[0023] With the above configuration, the first process or the second process is executed when the estimation accuracy is equal to or lower than the threshold accuracy, so that the first process or the second process can be executed at an appropriate timing.

[0024] The power storage device may be mounted on a vehicle. The charging process may be an external charging process in which the power storage device is charged using electric power from an electric power facility provided outside the vehicle. The charging amount may be an amount of electric power charged from the electric power facility to the power storage device from the start of the external charging process to the end of the external charging process.

[0025] With the above configuration, it is possible to improve the accuracy of estimating the full charge capacity when external charging is performed.

[0026] The vehicle of the present disclosure is equipped with the above-described estimation system. Effect of the Invention

[0027] According to the present disclosure, it is possible to both suppress deterioration of a power storage device and improve the accuracy of estimating the full charge capacity. [Brief description of the drawings]

[0028] [Figure 1] 1 is a diagram showing roughly the overall configuration of a vehicle according to a first embodiment. [Diagram 2] FIG. 13 is a diagram showing an example of a screen displayed on an HMI device of a user terminal for setting an upper limit SOC. [Diagram 3] 5 is a diagram for explaining an estimation process for estimating a full charge capacity of a battery. FIG. [Figure 4] 4 is a diagram for explaining a process for estimating a full charge capacity of a battery executed by an ECU in the first embodiment. FIG. [Diagram 5] FIG. 13 is a diagram showing an example of a screen displayed on a display device of a user terminal for raising an upper limit SOC. [Figure 6] FIG. 11 is a diagram showing another example of a screen displayed on the display device of the user terminal for raising the upper limit SOC. [Figure 7] 5 is a flowchart showing an example of a process executed by an ECU in relation to a limited charging process. [Figure 8] 5 is a flowchart showing an example of a process executed by an ECU in relation to raising an upper limit SOC in the first embodiment. [Figure 9] 10 is a flowchart showing another example of the process executed by the ECU in relation to the release of the upper limit SOC. [Figure 10] 10 is a flowchart showing an example of a process executed by an ECU in the first modification. [Figure 11] 11 is a diagram showing the relationship between the fully charged capacity of a battery and the time elapsed since the start of use of the battery. [Figure 12] 13 is a flowchart showing an example of a process executed by an ECU in a third modified example. [Figure 13] 13 is a flowchart showing an example of a process executed by an ECU in a fourth modified example. [Figure 14] 4 is a diagram for explaining a method in which the ECU determines the estimation accuracy of the full charge capacity of the battery. FIG. [Figure 15] 10 is a flowchart showing an example of a process executed by an ECU in relation to estimation of a full charge capacity in the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will not be repeated. Each of the embodiments and their modified examples may be appropriately combined as long as there is no contradiction.

[0030] [Embodiment 1] Fig. 1 is a diagram that shows a schematic overall configuration of a vehicle according to a first embodiment. With reference to Fig. 1, vehicle 1 is an electric vehicle (BEV: Battery Electric Vehicle) that includes a battery 10. Vehicle 1 is configured to be capable of performing external charging that charges battery 10 using power supplied from power equipment 85 (described later) that is provided outside vehicle 1.

[0031] The vehicle 1 includes a PCU (Power Control Unit) 30, an inlet 40, a charging device 50, a motor generator 62, drive wheels 66, and an estimation system 2.

[0032] The PCU 30 includes an inverter (not shown). The inverter is configured to convert DC power supplied from the battery 10 into AC power and supply the converted power to the motor generator 62.

[0033] The inlet 40 is configured to receive power through a charging cable from power equipment 85 provided outside the vehicle 1. A signal (cable connection signal PISW) indicating whether the vehicle 1 is connected to the power equipment 85 through the charging cable is transmitted from the inlet 40 to the ECU 100.

[0034] The charging device 50 is configured to charge the battery 10 by converting the power (AC power) received by the inlet 40 into DC power suitable for charging the battery 10. The charging device 50 is configured to include, for example, an inverter and a converter (neither of which are shown).

[0035] The motor generator 62 is an AC rotating electric machine, for example a three-phase AC synchronous motor with a permanent magnet embedded in the rotor. The motor generator 62 drives the drive wheels 66 using the electric power supplied from the PCU 30. This causes the vehicle 1 to run.

[0036] The estimation system 2 includes a battery 10, a monitoring unit 20, an HMI (Human Machine Interface) device 70, a communication device 80, and an ECU (Electronic Control Unit) 100.

[0037] The battery 10 is a secondary battery configured to store power for driving the vehicle 1. The state of charge of the battery 10 is represented by a State of Charge (SOC). The battery 10 may be replaced by another power storage device such as an electric double layer capacitor.

[0038] The monitoring unit 20 includes a voltage sensor 21, a current sensor 22, and a temperature sensor 23. The voltage sensor 21 detects the voltage VB of the battery 10. The current sensor 22 detects the current IB (e.g., the charging current of the battery 10) input to or output from the battery 10. The temperature sensor 23 detects the temperature TB of the battery 10.

[0039] The HMI device 70 includes a display device 72 and an input device 74. The display device 72 displays various information to a user of the vehicle 1. The input device 74 is configured to receive input of operations performed by the user of the vehicle 1. In this example, the display device 72 and the input device 74 configure a touch screen. The HMI device 70 may further include a speaker.

[0040] The communication device 80 is configured to communicate with devices (e.g., power equipment 85 and a user terminal 90) outside the vehicle 1. The communication device 80 exchanges various information with the power equipment 85, for example, by CAN (Controller Area Network) communication. The communication device 80 exchanges various information with the user terminal 90, for example, by wireless communication.

[0041] The ECU 100 includes a processor 100A and a memory 100B. The processor 100A is, for example, a central processing unit (CPU). The memory 100B includes a read only memory (ROM) and a random access memory (RAM). The ROM stores a program executed by the processor 100A. The RAM functions as a working memory.

[0042] The ECU 100 controls each device of the vehicle 1 (for example, the PCU 30, the charging device 50, the motor generator 62, the HMI device 70, and the communication device 80).

[0043] The ECU 100 determines the connection state between the vehicle 1 and the power equipment 85 (i.e., whether or not the vehicle 1 is connected to the power equipment 85) according to the signal level of the cable connection signal PISW. The ECU 100 receives a signal from the HMI device 70 indicating the result of a user operation performed on the input device 74 of the HMI device 70.

[0044] The ECU 100 is configured to execute a charging process for charging the battery 10. In the following description, a case where the charging process is an external charging process will be mainly described. The external charging process is a process for charging the battery 10 using power from the power equipment 85. In this example, the external charging process is a process for converting power from the power equipment 85 to the charging device 50 and charging the battery 10 using the converted power.

[0045] For example, the ECU 100 starts the external charging process when it receives from the power equipment 85 a signal indicating that an operation to instruct the start of power supply from the power equipment 85 to the vehicle 1 has been performed using an HMI device 85B (described later). Then, the ECU 100 determines whether the SOC of the battery 10 has reached a threshold SOC. The threshold SOC is, for example, a fully charged SOC (100%) that is the SOC when the battery 10 is fully charged, or an upper limit SOC that is lower than the fully charged SOC. A method for setting the upper limit SOC will be described in detail later. When the SOC reaches the threshold SOC, the ECU 100 ends the external charging. Specifically, the ECU 100 outputs a power supply stop request to the power equipment 85 so that power supply from the power equipment 85 to the vehicle 1 is ended.

[0046] When the external charging process is executed so that the SOC at the end of external charging is higher than a first reference value (e.g., 80%) and the SOC at the start of external charging is lower than a second reference value (e.g., 30%) that is less than the first reference value (i.e., when the external charging process is executed so that the SOC increases from the second reference value to the first reference value), this external charging process is also called a reference charging process. The end time of the reference charging process is also referred to as a "reference time."

[0047] The ECU 100 is configured to be capable of executing a limited charging process for charging the battery 10 so that the SOC of the battery 10 does not exceed an upper limit SOC. The limited charging process is executed in order to suppress deterioration of the battery 10.

[0048] The ECU 100 receives detection values ​​(voltage VB, current IB, and temperature TB) from the sensors of the monitoring unit 20. The ECU 100 calculates the SOC of the battery 10 in accordance with the above detection values.

[0049] The ECU 100 executes an "estimation process" for estimating the full charge capacity of the battery 10. The ECU 100 executes the estimation process according to the detection values ​​from the sensors of the monitoring unit 20 and the programs and maps stored in the memory 100B. The ECU 100 may execute the estimation process each time the charging process is executed, or may execute the estimation process each time the charging process is executed a predetermined number of times. The estimation process will be described in detail later.

[0050] The power equipment 85 includes a power source 85A and an HMI device 85B. The power source 85A is, for example, a commercial power source, and is configured to supply AC power to the vehicle 1. The HMI device 85B is configured to receive a user operation related to power supply from the power equipment 85 to the vehicle 1 (for example, an operation to start or stop power supply). A signal indicating the result of this user operation is transmitted to the vehicle 1 by, for example, CAN communication.

[0051] The user terminal 90 is a communication terminal that can be carried by a user of the vehicle 1, and is, for example, a smartphone. The user terminal 90 includes a communication device 98, an HMI device 94, and a control device 99. The communication device 98 is configured to communicate with the vehicle 1 wirelessly.

[0052] The HMI device 94 includes a display device 95 and an input device 97. The HMI device 94 may further include a speaker. The display device 95 displays various information to the user. The input device 97 receives input of a user operation. The user operation is, for example, an operation for setting an upper limit SOC at the time of completion of external charging of the vehicle 1. The display device 95 and the input device 97 form a touch screen.

[0053] The control device 99 controls each device (e.g., the HMI device 94 and the communication device 98) of the user terminal 90. For example, when the input device 97 receives an input of a user operation, the control device 99 transmits a signal indicating the result of the user operation to the vehicle 1 via the communication device 98.

[0054] FIG. 2 is a diagram showing an example of a screen displayed on the HMI device 94 of the user terminal 90 for setting an upper limit SOC.

[0055] Referring to FIG. 2, a screen 700 includes a message 710, a setting input portion 715, a setting display portion 720, and a button 725.

[0056] A message 710 prompts the user to input a setting value for the upper SOC limit. A setting input unit 715 receives an input of a setting value (X%) for the upper SOC limit from the user. A setting display unit 720 displays the current setting value (Y%) for the upper SOC limit.

[0057] Button 725 is provided for receiving a user operation for outputting the set value of the upper limit SOC to vehicle 1. When button 725 is operated with the set value of the upper limit SOC (X%) input to setting input unit 715, the set value of the upper limit SOC is output from user terminal 90 to vehicle 1. As a result, the set value of the upper limit SOC is overwritten (from Y% to X%).

[0058] 3 is a diagram for explaining an estimation process for estimating the full charge capacity of the battery 10. This example is a comparative example in which the ECU 100 does not execute the process described below.

[0059] Referring to FIG. 3, ΔSOC is the difference between the start SOC (SOC1) and end SOC (SOC2) when external charging processing is executed (ΔSOC=SOC2-SOC1). The start SOC is the SOC at the start of external charging. The end SOC is the SOC at the end of external charging. In this example, the end SOC is equal to the upper limit SOC set in the limited charging processing, which is SOC2A. SOCF corresponds to the fully charged SOC.

[0060] The ECU estimates the full charge capacity by dividing the charge amount (ΔAh) charged to the battery 10 by the external charging process by ΔSOC indicating the increment of SOC by the external charging process. That is, the ECU estimates the estimated value Ce of the full charge capacity of the battery 10 according to the following equation (1).

[0061] Ce=(ΔAh / ΔSOC)×100 [Ah] …(1) ΔAh is the integrated value (time integrated value) of the current IB from the start of external charging to the end of external charging. The larger ΔSOC is, the higher the accuracy of the estimated value Ce is. On the other hand, if ΔSOC is large enough that the battery 10 is charged to a fully charged state, the battery 10 is likely to deteriorate due to the battery 10 being in a highly charged state.

[0062] In recent years, the capacity of the battery 10 has been increasing. When the capacity of the battery 10 increases, it may be preferable not to charge the battery 10 to a fully charged state in order to suppress deterioration of the battery 10. For example, an upper limit SOC lower than the fully charged SOC of the battery 10 may be set (using the screen 700 of FIG. 2 as an example) and a limited charging process may be executed. When the battery 10 is not charged to a fully charged state, there are many cases in which the ΔSOC associated with charging is smaller than when the battery 10 is charged to a fully charged state. As a result, the accuracy of the full charge capacity estimated using the above formula (1) (the accuracy of the estimated value Ce) may decrease.

[0063] For example, when an upper limit SOC is set, ΔSOC in the above formula (1) is smaller than when an upper limit SOC is not set (when the charging end SOC is the full charge SOC) (assuming that the charging start SOC is the same). As a result, the estimated value Ce varies more, and the accuracy of the estimated value Ce may decrease. In particular, when the battery 10 is not fully charged for a long period of time, the accuracy of the estimated value Ce decreases significantly. Thus, when an upper limit SOC is set, the accuracy of the estimated value Ce may decrease.

[0064] Vehicle 1 according to the first embodiment has a configuration for dealing with the above problems, which will be described in detail below.

[0065] FIG. 4 is a diagram for explaining the process of estimating the full charge capacity of the battery 10 executed by the ECU 100 in the first embodiment.

[0066] Referring to FIG. 4, the ECU 100 performs the estimation process of the full charge capacity (the calculation process of the estimated value Ce) by dividing ΔAh by ΔSOC in the above formula (1) in the same manner as in the comparative example (FIG. 3). On the other hand, the ECU 100 performs the first process or the second process when a predetermined condition indicating a decrease in the estimation accuracy of the full charge capacity is satisfied. The first process is a process of performing the charging process by raising the upper limit SOC set in the limited charging process to a value higher than that when the above-mentioned predetermined condition is not satisfied (raising it from SOC2A to SOC2B). In this example, SOC2B is equal to SOCF, but may be within a range between SOC2A and SOCF. The second process is a process of performing the charging process without performing the limited charging process. The second process is a process of canceling the setting of the upper limit SOC (i.e., even if the upper limit SOC is set, the above-mentioned threshold SOC is set to the full charge SOC instead of the upper limit SOC) and performing the charging process so that the charging end SOC becomes the full charge SOC. The second process may be a process of canceling a user operation to set the upper limit SOC using the screen 700 and executing an external charging process (so that the battery 10 is charged to a fully charged state). If the above-mentioned predetermined condition is not satisfied, the ECU 100 executes the limited charging process in a state where the upper limit SOC is SOC2A.

[0067] With the above configuration, when the predetermined condition is not met, the limited charging process is executed, and the battery 10 is not charged to a full charge state. As a result, deterioration of the battery 10 is suppressed. On the other hand, when the predetermined condition is met, the charging process is executed with the upper limit SOC raised (first process), or the charging process is executed without executing the limited charging process (i.e., with the upper limit SOC not set) (second process).

[0068] When the first process is executed, the upper limit SOC (SOC2 as the end-of-charge SOC) is raised more than in the comparative example. This increases ΔSOC from ΔSOC1 to ΔSOC2. That is, ΔSOC in the above formula (1) becomes larger than in the comparative example. As a result, the variation in the estimated value Ce is reduced more than in the comparative example. Therefore, the error in the estimated value Ce is reduced, and the accuracy of the estimated value Ce (the estimation accuracy of the full charge capacity) is improved.

[0069] Alternatively, when the second process is executed, the SOC (SOC2) at the end of external charging becomes the full charge SOC (SOCF). This increases ΔSOC compared to the comparative example. As a result, the accuracy of estimating the full charge capacity can be improved. As described above, according to the first embodiment, it is possible to both suppress deterioration of the battery 10 and improve the accuracy of estimating the full charge capacity.

[0070] The first process or the second process is particularly effective when executed by the ECU 100 in a case where the upper limit SOC is set by the user (for example, using the screen 700 in FIG. 2). In this way, the first process or the second process is executed while allowing the user to set the upper limit SOC. As a result, it is possible to improve the accuracy of estimating the full charge capacity while improving the convenience for the user.

[0071] When the ECU 100 executes the first process or the second process, the ECU 100 may further execute a notification process for notifying a user of the execution of the first process or the second process (that is, that the first process or the second process is being executed).

[0072] For example, when the execution of the first process is notified to the user, the user is motivated to raise the upper limit SOC from the current setting value (for example, Y% in FIG. 2) (for example, using the screen 700). This makes it possible to raise the upper limit SOC. Furthermore, it is possible to improve user convenience.

[0073] FIG. 5 is a diagram showing an example of a screen displayed on the display device 95 of the user terminal 90 for raising the upper limit SOC.

[0074] 5, the screen 900 is displayed when the battery 10 has not been fully charged for a long period of time (e.g., a predetermined period of time such as one month). The screen 900 includes a message 927. The message 927 prompts the user to fully charge the battery 10 within N external charging times. In this example, the message 927 prompts the user to set the upper limit SOC to the fully charged SOC using the screen 700 displayed on the user terminal 90.

[0075] If the battery 10 is not fully charged after the screen 900 is displayed, the number "N" in the message 927 will be smaller the next time the screen 900 is displayed. The smaller N may be displayed more highlighted. For example, if N is equal to or greater than a predetermined threshold, N may be displayed in a first color (e.g., blue), while if N falls below the threshold, N may be displayed in a second color (e.g., a warning color such as red). Highlighting N in this manner can effectively prompt the user to fully charge the battery 10 as soon as possible.

[0076] The ECU 100 may be configured to notify the user to inquire whether or not the user agrees to raising the upper limit SOC. Inquiring the user in this manner can further improve user convenience. This will be described in detail below.

[0077] FIG. 6 is a diagram showing another example of a screen displayed on the display device 95 of the user terminal 90 for raising the upper limit SOC.

[0078] 6, a screen 950 is displayed when the battery 10 has not been fully charged for an extended period of time (e.g., a predetermined period of time). The screen 900 includes a message 960 and buttons 965 and 970. The message 960 asks the user whether or not to increase the upper SOC limit from its current setting.

[0079] The buttons 965 and 970 are operated by the user. When the button 965 is operated, the ECU 100 increases the upper limit SOC from the currently set value. When the button 970 is operated, the upper limit SOC is maintained at the currently set value.

[0080] 7 is a flowchart showing an example of a process related to the limited charging process and executed by the ECU 100. The process of this flowchart is started when the vehicle 1 is connected to the power equipment 85 in a case where the upper limit SOC is set.

[0081] 7, the ECU 100 sets the FLAG to 0 (step S105). The FLAG is used by the ECU 100 to determine whether the battery 10 is sufficiently charged or not.

[0082] Next, the ECU 100 determines whether or not an instruction to start external charging of the vehicle 1 has been issued (step S110). The ECU 100 receives, for example, a signal indicating whether or not an instruction to supply power from the power equipment 85 to the vehicle 1 has been issued from the power equipment 85 by CAN communication using the HMI device 85B. Then, the ECU 100 executes the determination process of step S110 according to the signal.

[0083] When the start of external charging has not been instructed (NO in step S110), ECU 100 executes the above-described determination process until the start of external charging is instructed. On the other hand, when the start of external charging has been instructed (YES in step S110), the process proceeds to step S115.

[0084] Next, ECU 100 determines whether or not the charging start SOC is lower than a reference value RVS (step S115). The reference value RVS corresponds to the second reference value described above, and is appropriately set in advance as a value lower than a reference value RVE described below (e.g., 30%). If the charging start SOC is equal to or higher than the reference value RVS (NO in step S115), the process proceeds to step S125. On the other hand, if the charging start SOC is lower than the reference value RVS (YES in step S115), ECU 100 sets FLAG to 1 (step S120), and proceeds to step S125.

[0085] Next, ECU 100 determines whether or not the SOC has reached the upper limit SOC (step S125). If the SOC has not reached the upper limit SOC (NO in step S125), ECU 100 executes this determination process until the SOC reaches the upper limit SOC. On the other hand, if the SOC has reached the upper limit SOC (YES in step S125), ECU 100 ends external charging (step S126). In this case, the charging end SOC is the upper limit SOC. Then, the process proceeds to step S130.

[0086] Next, the ECU 100 switches the process depending on whether the end-of-charge SOC is higher than the reference value RVE (step S130). The reference value RVE corresponds to the above-mentioned first reference value, and is appropriately determined in advance as a value equal to or lower than the full-charge SOC (for example, 80%).

[0087] If the end-of-charge SOC is equal to or lower than the reference value RVE (NO in step S130), the process in FIG. 7 ends.

[0088] On the other hand, if the end-of-charge SOC is higher than the reference value RVE (YES in step S130), ECU 100 branches the process according to the value of FLAG (step S135). If FLAG is 0 (NO in step S135), the process in FIG.

[0089] On the other hand, if FLAG is 1 (YES in step S135), the external charging process starts with the start-of-charging SOC being sufficiently low so as to fall below the reference value RVS (YES in step S115), and ends with the end-of-charging SOC being sufficiently high so as to exceed the reference value RVE (YES in step S130). When the external charging process starts and ends in this manner, the external charging process is a reference charging process. When the ECU 100 executes the reference charging process, it determines that the battery 10 is sufficiently charged, and stores the charging end time (reference time) in the memory 100B (step S140). Thereafter, the process of FIG. 7 ends.

[0090] 8 is a flowchart showing an example of a process executed by the ECU 100 in relation to raising the upper limit SOC in the embodiment 1. The process of this flowchart is executed at predetermined time intervals.

[0091] 8, ECU 100 determines whether a predetermined condition indicating a decrease in the estimation accuracy of the full charge capacity is satisfied (step S205). In this example, the predetermined condition is that a state in which the reference charging process is not executed continues for a threshold duration THD or more from a reference time. Therefore, the determination process of step S205 corresponds to a process of determining whether a state in which battery 10 is not sufficiently charged continues for the threshold duration THD or more. The threshold duration THD is appropriately determined in advance by experiment as a time during which the estimation accuracy of the full charge capacity of battery 10 does not substantially change if the time during which the reference charging process is not executed continues for less than the threshold duration THD.

[0092] If the state in which the reference charging process is not being executed has not continued for the threshold duration THD or more from the reference time (NO in step S205), ECU 100 ends the process in Fig. 8. If ECU 100 executes the external charging process during the period until the above state continues for the threshold duration THD or more, ECU 100 executes the limited charging process. On the other hand, if the above state continues for the threshold duration THD or more (YES in step S205), the process proceeds to step S210.

[0093] Next, the ECU 100 executes a process of notifying the user to increase the upper limit SOC from the current setting value (for example, to the full charge SOC) (step S210). In this example, the ECU 100 outputs a request to the user terminal 90 through the communication device 80 to display a screen 950 (FIG. 6) on the display device 95 of the user terminal 90.

[0094] Next, the ECU 100 determines whether or not permission to increase the upper limit SOC is granted (step S215).

[0095] When permission to increase the upper limit SOC is granted, for example, when button 965 on screen 950 is operated within a predetermined time (YES in step S215), ECU 100 increases the upper limit SOC set in the limited charging process from the current setting (step S220). The setting before the increase is equal to the setting of the upper limit SOC when the limited charging process is executed when the process branches to NO in step S205.

[0096] On the other hand, if permission to increase the upper limit SOC is not granted, for example, if button 970 on screen 950 is operated within a predetermined time (NO in step S215), ECU 100 maintains the upper limit SOC at the current setting value (step S225).

[0097] After step S220 or S225, ECU 100 switches the process depending on whether external charging has been performed (step S230). When external charging is performed after step S220, ECU 100 executes the charging process in a state where the upper limit SOC is increased compared to when the above-mentioned predetermined condition is not satisfied (first process). When external charging is performed after step S225, the charging process is executed in a state where the upper limit SOC is maintained.

[0098] If external charging has not been performed after step S220 or S225 and before step S230 (NO in step S230), ECU 100 executes the determination process of step S230 until external charging is performed. On the other hand, if external charging has been performed (YES in step S230), the process proceeds to step S240.

[0099] Next, the ECU 100 executes an estimation process to estimate the full charge capacity of the battery 10 using the above formula (1) (step S240).

[0100] In the above description, when a predetermined condition is met (for example, YES in step S205), ECU 100 increases the upper limit SOC and executes external charging processing (first processing) and notifies the user of this (step S210), but it may also execute external charging processing (so that battery 10 is fully charged) (second processing) without executing limited charging processing and notify the user of this. Below, a description will be given of a process in which ECU 100 executes the second processing in place of the first processing in association with the release of the upper limit SOC.

[0101] In step S210, the ECU 100 notifies the user to cancel the upper limit SOC. In the next step S215, the ECU 100 switches the process depending on whether or not permission to cancel the upper limit SOC has been granted. If permission has been granted, the ECU 100 cancels the upper limit SOC in step S220. If external charging is performed after the upper limit SOC has been released, the ECU 100 executes the charging process without executing the limited charging process. Then, the full charge capacity estimation process is executed (step S240).

[0102] 9 is a flowchart showing another example of the process related to the release of the upper limit SOC, which is executed by the ECU 100. The process of this flowchart is executed at predetermined time intervals.

[0103] 9, the processes in steps S305 and S340 are similar to those in steps S205 and S240 (FIG. 8), respectively.

[0104] Next, ECU 100 determines whether or not a user operation for setting the upper limit SOC has been performed (step S310). If the user operation has not been performed (NO in step S310), ECU 100 ends the process in Fig. 9. On the other hand, if the user operation has been performed (YES in step S310), the set value of the upper limit SOC is output from user terminal 90 to vehicle 1, and the process proceeds to step S312.

[0105] Next, ECU 100 determines whether the set value of the upper limit SOC output by the user operation is lower than a predetermined value (step S312). This predetermined value is, for example, the same as reference value RVE. If the set value is equal to or higher than the predetermined value (NO in step S312), the possibility that battery 10 is sufficiently charged is relatively high. In this case, processing proceeds to step S330. On the other hand, if the set value of the upper limit SOC is lower than the predetermined value (YES in step S312), the possibility that battery 10 is sufficiently charged is relatively low. In this case, processing proceeds to step S315.

[0106] Next, the ECU 100 executes a process of notifying the user that the external charging process will be executed without executing the limited charging process (in this example, the set value of the upper limit SOC output by the user operation will be canceled and the external charging process will be executed) (step S315). The ECU 100 outputs a request to the user terminal 90 through the communication device 80, for example, to display a screen for this notification on the display device 95 of the user terminal 90.

[0107] Next, the ECU 100 determines whether or not the user has agreed to the execution of the external charging process without executing the restricted charging process (step S320). The ECU 100 receives, for example, a signal indicating whether or not the user has agreed (i.e., a signal indicating the result of a user operation performed on the HMI device 94 of the user terminal 90 in response to the notification in step S315) from the user terminal 90 via the communication device 80, and executes the above-mentioned determination process in accordance with the signal.

[0108] If the user agrees (YES in step S320), ECU 100 cancels the set value of the upper limit SOC output from user terminal 90 (step S325). Then, ECU 100 determines whether or not an instruction to start external charging has been issued (step S335). If an instruction to start external charging has not been issued (NO in step S335), ECU 100 executes the above-described determination process until an instruction to start external charging is issued. On the other hand, if an instruction to start external charging has been issued (YES in step S335), ECU 100 executes the external charging process without executing the limited charging process (step S336).

[0109] If the user does not agree in step S320 (NO in step S320), ECU 100 sets the upper limit SOC in accordance with the user operation (step S330). That is, ECU 100 sets the setting value output by the user operation as the upper limit SOC.

[0110] Next, ECU 100 determines whether or not a command to start external charging has been issued (step S338). If a command to start external charging has not been issued (NO in step S338), ECU 100 executes the above-described determination process until a command to start external charging is issued. On the other hand, if a command to start external charging has been issued (YES in step S338), ECU 100 executes external charging processing according to the upper limit SOC set by a user operation (step S339).

[0111] After step S336 or step S339, the ECU 100 executes a process for estimating a full charge capacity (step S340), and ends the process of FIG.

[0112] The ECU 100 may increase (e.g., stepwise) the predetermined value in step S312 as the time (duration) during which the state in which the reference charging process is not executed continues from the reference time becomes longer. As a result, if the duration is sufficiently long, the predetermined value becomes high enough to be substantially equal to the full-charge SOC. As a result, the set value of the upper limit SOC output by the user operation can be canceled unless the set value is sufficiently high so as to be close to the full-charge SOC. As a result, only a sufficiently high upper limit SOC can be set, so that the upper limit SOC (charging end SOC) can be necessarily made sufficiently high. Therefore, the estimation accuracy of the full-charge capacity can be improved.

[0113] As described above, according to the estimation system 2 of the present embodiment, it is possible to both suppress deterioration of the battery 10 and improve the accuracy of estimating the full charge capacity.

[0114] [First Modification of First Embodiment] In this modified example 1, the ECU 100 further executes a reduction notification process for notifying a user before the execution of the first process to reduce the charging start SOC when the first process is executed. For example, the ECU 100 outputs a request to the user terminal 90 through the communication device 80 to display on the display device 95 of the user terminal 90 a screen notifying the user to start external charging in a state in which the charging start SOC is lower than the reference value RVS in addition to the screen 950 ( FIG. 6 ).

[0115] With this configuration, the user is motivated to lower the charging start SOC. That is, the user is prompted to use the vehicle 1 until the SOC becomes sufficiently low. In response to the above notification, the user can start external charging of the vehicle 1 in a state in which the charging start SOC is lowered from the normal charging start SOC. The normal charging start SOC is the SOC when the user often desires to start external charging of the vehicle 1 in daily life. When external charging is started as described above, the charging start SOC is lowered, so that ΔSOC can be further increased.

[0116] 10 is a flowchart showing an example of processing executed by the ECU 100 in this modified example 1. The processing of this flowchart is executed at predetermined time intervals.

[0117] 10, this flowchart differs from the flowchart of FIG 8 in that the process of step S412 is executed instead of step S210 (FIG 8). The processes of steps S405, and S415 to S440 are similar to the processes of steps S205, and S215 to S240, respectively.

[0118] When a predetermined condition indicating a decrease in the estimation accuracy of the full charge capacity is satisfied (YES in step S405), ECU 100 executes a process to raise the upper limit SOC and notify the user to lower the charging start SOC before executing the first process (step S412). This notification process includes the above-mentioned lowering notification process. Then, the process proceeds to step S415. Then, when permission is granted in step S415 (YES in step S415), the upper limit SOC is raised and then the external charging process is executed (first process).

[0119] When the user uses the vehicle 1 so that the start-of-charging SOC at the start of the external charging process is lowered below the normal start-of-charging SOC, the ΔSOC can be increased more than when the start-of-charging SOC is not lowered. As a result, according to the first modification, the process of estimating the full charge capacity can be more appropriately executed.

[0120] [Modification 2 of the First Embodiment] The threshold duration THD may be determined so as to be shorter as the time that has elapsed since the start of use of the battery 10 becomes shorter. The start of use of the battery 10 refers to, for example, when a new battery 10 is installed in the vehicle 1 at a factory or when a user registers the vehicle 1 using the HMI device 94.

[0121] FIG. 11 is a diagram showing the relationship between the full charge capacity of the battery 10 and the time elapsed since the start of use of the battery 10. In FIG.

[0122] 11, time t0 is the start of use of battery 10. Period P1 is the period from time t0 to t3. Period P2 is the period from time t3 to t5. The length of each of periods P1 and P2 is ΔT.

[0123] Line 500 indicates the transition of the full charge capacity of battery 10. Line 500 indicates that the shorter the elapsed time t from time t0, the easier it is for the full charge capacity to decrease. For example, during period P1, the full charge capacity is easier to change (decrease) than during period P2 (the rate of change of the full charge capacity is higher). Therefore, during period P1, a more accurate estimation process of the full charge capacity is required compared to other periods (for example, period P2).

[0124] In this example, the ECU 100 determines the threshold duration THD for each period such that the threshold duration THD for the period P1 (THD11) is shorter than the threshold duration THD for the period P2 (THD12) (THD11). <THD12)。

[0125] For example, during period P1, if a state in which the reference charging process is not executed continues for a threshold duration THD (THD11) from time t1 as the reference time (after time t2), ECU 100 executes the first process or the second process.

[0126] On the other hand, during period P2, if the state in which the reference charging process is not executed continues for the threshold duration THD (THD12) from time t4 as the reference time (after time t5), ECU 100 executes the first process or the second process.

[0127] When the threshold duration THD is determined as described above, the threshold duration THD becomes shorter as the period in which the estimation accuracy is more likely to change. This makes it easier to execute the first process or the second process. This increases the frequency of the first process or the second process. Therefore, it is possible to increase the frequency at which the full charge capacity estimation process is appropriately executed.

[0128] [Third Modification of First Embodiment] The predetermined condition indicating a decrease in the accuracy of estimating the full charge capacity may be a condition in which the state in which the upper limit SOC is set by the user continues for a threshold time or more. The threshold time is appropriately determined in advance as a time during which the accuracy of estimating the full charge capacity of the battery 10 does not substantially change if the state continues for less than the threshold time.

[0129] The longer the above state continues, the longer the battery 10 is not fully charged. Therefore, the possibility that the estimation process is executed when ΔSOC is small increases. As a result, the accuracy of estimating the full charge capacity may decrease. When the predetermined condition is determined as described above, the limited charging process can be executed until the state in which the upper limit SOC is set by the user continues for a threshold time or more. On the other hand, if this state continues for a threshold time or more, the first process or the second process is executed. In the following description, the case in which the first process is executed out of the first process and the second process will be mainly described.

[0130] 12 is a flowchart showing an example of a process executed by the ECU 100 in this modified example 3. The process of this flowchart is executed at predetermined time intervals.

[0131] 12, this flowchart differs from the flowchart of FIG 8 in that the process of step S506 is executed instead of step S205 (FIG 8). The processes of steps S510 to S540 are similar to the processes of steps S210 to S240, respectively.

[0132] ECU 100 determines whether the state in which the upper limit SOC is set by the user continues for a threshold time THT or more (step S506). If this state has not continued for the threshold time THT or more (NO in step S506), ECU 100 ends the process in FIG. 12. On the other hand, if the above state has continued for the threshold time THT or more (YES in step S506), the process proceeds to step S510. Thereafter, in step S520, the upper limit SOC is raised and a charging process is executed (first process). If the above state has continued for the threshold time THT or more, ECU 100 may execute an external charging process without executing a limited charging process (second process).

[0133] As described above, according to the third modification, the first process or the second process can be executed at an appropriate timing.

[0134] [Fourth Modification of the First Embodiment] The predetermined condition indicating a decrease in the accuracy of estimating the full charge capacity may be a condition in which the limited charging process is executed a threshold number of times or more in succession when the external charging process is executed. The threshold number of times is appropriately determined in advance as a value for preventing a decrease in the accuracy of estimating the full charge capacity.

[0135] The more the number of times the limited charging process is executed in succession, the longer the time during which the battery 10 is not fully charged. Therefore, the likelihood that the estimation process will be executed when ΔSOC is small increases. As a result, the accuracy of estimating the full charge capacity may decrease. When the predetermined condition is determined as described above, the first process or the second process is executed when the limited charging process has been executed in succession a threshold number of times or more. In the following description, the case in which the first process is executed out of the first process and the second process will be mainly described.

[0136] 13 is a flowchart showing an example of a process executed by the ECU 100 in this modified example 4. The process of this flowchart is executed at predetermined time intervals.

[0137] 13, this flowchart differs from the flowchart of FIG 8 in that the process of step S606 is executed instead of step S205 (FIG 8) and in that the process of step S650 is further executed. The processes of steps S610 to S640 are similar to the processes of steps S210 to S240, respectively.

[0138] The ECU 100 determines whether the limited charging process has been executed consecutively a threshold number of times THN or more (step S606). The number of times the limited charging process has been executed consecutively (number of executions N) is stored in the memory 100B. When the ECU 100 executes the limited charging process, it counts up the number of executions N by 1, and executes the above determination process by determining whether the number of executions N after the count-up is equal to or greater than the threshold number of times THN.

[0139] If the limited charging process has not been executed consecutively the threshold number of times THN or more (NO in step S606), ECU 100 executes the process in Fig. 13. On the other hand, if the limited charging process has been executed consecutively the threshold number of times THN or more (YES in step S606), the process proceeds to step S610.

[0140] After the processes of steps S610 to S640 are executed, the ECU 100 resets the execution count N to 0 (step S650) and ends the process of FIG. 13.

[0141] As described above, according to this Modification 4, the first process or the second process can be executed at an appropriate timing.

[0142] [Embodiment 2] In this Embodiment 2, the estimation accuracy of the full charge capacity of the battery 10 is determined (calculated) according to the charge start SOC and the charge end SOC, and when the estimation accuracy is equal to or lower than a threshold value, the first or second process is executed. In this case, the predetermined condition indicating a decrease in the estimation accuracy of the full charge capacity may be a condition where the estimation accuracy becomes equal to or lower than the threshold accuracy.

[0143] FIG. 14 is a diagram for explaining a method by which the ECU 100 determines the estimation accuracy of the full charge capacity of the battery 10.

[0144] Referring to FIG. 14, a table 800 is stored in the memory 100B. The table 800 shows the relationship between the combination of the charge start SOC (SOC1) and the charge end SOC (SOC2 > SOC1) and the estimation accuracy of the full charge capacity.

[0145] When external charging ends, the ECU 100 uses the table 800 to determine the estimation accuracy of the full charge capacity according to the charge start SOC and the charge end SOC. For example, when the charge start SOC is SOCA and the charge end SOC is SOCB (SOCA < SOCB), the ECU 100 determines the estimation accuracy as PAB.

[0146] Basically, the estimation accuracy is higher as the difference (ΔSOC = SOC2 - SOC1) between the charge start SOC and the charge end SOC is larger. For example, PAD > PAC > PAB. The estimation accuracy corresponding to the combination of the charge start SOC and the charge end SOC is appropriately determined in advance by experiments based on the characteristics of the battery 10.

[0147] The ECU 100 may calculate the estimation accuracy of the full charge capacity according to the estimation accuracy and the history of the estimation accuracy of the full charge capacity, instead of the estimation accuracy itself determined using the table 800. This history is assumed to be stored in the memory 100B. When the estimation accuracy of the full charge capacity is calculated in this manner, the history of the estimation accuracy of the full charge capacity can be reflected in the calculation process of the estimation accuracy of the full charge capacity.

[0148] The ECU 100 calculates the estimation accuracy of the full charge capacity by using, for example, the following equation (2), and executes the first process or the second process when the estimation accuracy is equal to or lower than the threshold accuracy.

[0149] PRn=PR(n-1)×(1-RR)+Pn×RR…(2) In the above formula (2), PRn represents the estimation accuracy of the full charge capacity calculated when the nth external charging is performed (in this example, when the current external charging is performed) from the start of use of the battery 10. PRn is related to the following PR(n-1), and therefore reflects the history of the estimation accuracy of the full charge capacity.

[0150] PR(n-1) represents the estimation accuracy of the full charge capacity calculated when the (n-1)th external charging is performed (the previous time when external charging was performed).

[0151] Pn is the estimation accuracy of the full charge capacity that is determined when the current external charging is performed, using the table 800 itself. In other words, Pn is unrelated to the history of the estimation accuracy of the full charge capacity.

[0152] RR is a reflection rate (0≦RR≦1) indicating to what extent Pn related to the current external charging and PR(n-1) related to the previous external charging are each reflected in PRn. The closer RR is to 1, the more Pn related to the current external charging is reflected in PRn. For example, when RR is 1, the second term on the right side of the above equation (2) coincides with Pn. RR is appropriately determined in advance through a prior evaluation test.

[0153] Fig. 15 is a flowchart showing an example of a process executed by the ECU 100 in relation to estimating the full charge capacity in the second embodiment. This flowchart is started when the vehicle 1 is connected to the power equipment 85 in a case where an upper limit SOC is set. In the following description, Figs. 7 to 9 will be referred to as appropriate.

[0154] 15, ECU 100 executes the same processes as steps S105 to S140 (FIG. 7).

[0155] Next, the ECU 100 determines the estimation accuracy of the full charge capacity by using the table 800 according to the charging start SOC and the charging end SOC (step S750). The ECU 100 may further use the above formula (2) to calculate the estimation accuracy of the full charge capacity.

[0156] Next, ECU 100 determines whether the estimation accuracy is equal to or lower than the threshold accuracy (step S755). If the estimation accuracy is higher than the threshold accuracy (NO in step S755), ECU 100 maintains the upper limit SOC at the current setting value (similar process to step S225). After that, ECU 100 executes the same processes as steps S230 to S240 (FIG. 8).

[0157] On the other hand, if the estimation accuracy is equal to or lower than the threshold accuracy (YES in step S755), ECU 100 executes a process of informing the user to increase the upper limit SOC from the current setting value (similar process to step S210). After that, ECU 100 executes the same processes as steps S215 to S240. ECU 100 executes, for example, the first process (steps S220, S235).

[0158] In the above, when the estimation accuracy is equal to or lower than the threshold accuracy, ECU 100 executes the same processes as steps S215 to S240, but may execute the processes of steps S310 to S340 (FIG. 9). In these processes, when the process branches to YES in step S335, ECU 100 executes the process of step S336 (second process).

[0159] As described above, according to the second embodiment, the first process or the second process can be executed at an appropriate timing.

[0160] [Other variations] The ECU 100 may output a request to the user terminal 90 via the communication device 80 to display the estimation accuracy calculated using the table 800 and the estimation accuracy of the full charge capacity (estimated value Ce) on a display device 95 of the user terminal 90. In order to guarantee the quality of a power storage device mounted on an electric vehicle such as the vehicle 1, it may be required by law to display the full charge capacity of the power storage device to a user with high accuracy. When a request is output as described above, such a law can be satisfied.

[0161] The notification to the user may be performed by audio using a speaker of the HMI device 94. Alternatively, the notification to the user may be performed by a screen display using the display device 72 of the HMI device 70 of the vehicle 1, or by audio using the speaker of the HMI device 70.

[0162] The power equipment 85 may be a DC power equipment. That is, the power equipment 85 may further include a power conversion device that converts AC power supplied from the power source 85A into DC power. In this case, the charging device 50 of the vehicle 1 is not essential, and the above-mentioned DC power is directly supplied to the battery 10 without going through the charging device 50. Even when the power equipment 85 is a DC power equipment in this way, the first process and the second process by the ECU 100 are effective in terms of improving the estimation accuracy of the full charge capacity.

[0163] The power equipment 85 may include a power transmission device that wirelessly transmits power to the vehicle 1. In this case, the vehicle 1 may further include a power receiving device that wirelessly receives power from the power transmission device. The ECU 100 may be configured to execute, as the external charging process, a wireless charging process that charges the battery 10 using the power received by the power receiving device.

[0164] The vehicle 1 may be another type of electric vehicle, such as a plug-in hybrid electric vehicle (PHEV) further equipped with an engine, as long as the ECU 100 is capable of executing an external charging process.

[0165] The screen 700 (FIG. 2) may be displayed on the HMI device 70 of the vehicle 1. That is, the user can set the upper limit SOC using the HMI device 70. In this case, the set value of the upper limit SOC is output from the HMI device 70 to the ECU 100.

[0166] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, and it is intended to include all modifications within the scope and meaning equivalent to the claims. [Explanation of symbols]

[0167] 1 vehicle, 2 estimation system, 10 battery, 70, 85B, 94 HMI device, 85 power equipment, 100A processor, 100B memory, 800 table.

Claims

1. A power storage device; a processing device configured to execute a charging process for charging the power storage device and an estimation process for estimating a full charge capacity of the power storage device; the charging process includes a limited charging process of charging the power storage device so that the SOC of the power storage device does not exceed an upper limit SOC that is lower than a full charge SOC of the power storage device, the estimation process includes a process of estimating the full charge capacity by dividing an amount of charge charged to the power storage device by a ΔSOC indicating an increment of the SOC by the charging process, The processing device includes: When a condition indicating a decrease in the accuracy of estimating the full-charge capacity is satisfied, a first process or a second process is executed; When the condition is not satisfied, the limited charging process is executed. The first process includes a process of executing the charging process by raising the upper limit SOC set in the limited charging process to a value higher than that in a case where the condition is not satisfied, the second process includes a process of executing the charging process without executing the limited charging process, When the upper limit SOC is set by a user, the processing device executes the first process or the second process; The condition includes a condition that a state in which the upper limit SOC is set by the user continues for a threshold time or more.

2. The estimation system according to claim 1 , wherein the condition includes a condition that the limited charging process is executed consecutively a threshold number of times or more.

3. A power storage device; a processing device configured to execute a charging process for charging the power storage device and an estimation process for estimating a full charge capacity of the power storage device; the charging process includes a limited charging process of charging the power storage device so that the SOC of the power storage device does not exceed an upper limit SOC that is lower than a full charge SOC of the power storage device, the estimation process includes a process of estimating the full charge capacity by dividing an amount of charge charged to the power storage device by a ΔSOC indicating an increment of the SOC by the charging process, The processing device includes: When a condition indicating a decrease in the accuracy of estimating the full-charge capacity is satisfied, a first process or a second process is executed; When the condition is not satisfied, the limited charging process is executed. The first process includes a process of executing the charging process by raising the upper limit SOC set in the limited charging process to a value higher than that in a case where the condition is not satisfied, the second process includes a process of executing the charging process without executing the limited charging process, When the upper limit SOC is set by a user, the processing device executes the first process or the second process; The condition includes a condition that the limited charging process is executed consecutively a threshold number of times or more.

4. The estimation system according to claim 1 , wherein the processing device further executes a notification process for notifying a user that the first process or the second process is executed when the first process or the second process is executed.

5. The estimation system according to claim 4 , wherein the processing device further executes a reduction notification process for notifying a user to reduce an SOC at the start of charging of the power storage device when the first process is executed.

6. A power storage device; a processing device configured to execute a charging process for charging the power storage device and an estimation process for estimating a full charge capacity of the power storage device; the charging process includes a limited charging process of charging the power storage device so that the SOC of the power storage device does not exceed an upper limit SOC that is lower than a full charge SOC of the power storage device, the estimation process includes a process of estimating the full charge capacity by dividing an amount of charge charged to the power storage device by a ΔSOC indicating an increment of the SOC by the charging process, The processing device includes: When a condition indicating a decrease in the accuracy of estimating the full-charge capacity is satisfied, a first process or a second process is executed; When the condition is not satisfied, the limited charging process is executed. The first process includes a process of executing the charging process by raising the upper limit SOC set in the limited charging process to a value higher than that in a case where the condition is not satisfied, the second process includes a process of executing the charging process without executing the limited charging process, The processing device further executes a notification process of notifying a user when the first process or the second process is executed; The processing device further executes a reduction notification process for notifying a user to reduce an SOC at the start of charging of the power storage device when the first process is executed.

7. A power storage device; a processing device configured to execute a charging process for charging the power storage device and an estimation process for estimating a full charge capacity of the power storage device; the charging process includes a limited charging process of charging the power storage device so that the SOC of the power storage device does not exceed an upper limit SOC that is lower than a full charge SOC of the power storage device, the estimation process includes a process of estimating the full charge capacity by dividing an amount of charge charged to the power storage device by a ΔSOC indicating an increment of the SOC by the charging process, The processing device includes: When a condition indicating a decrease in the accuracy of estimating the full-charge capacity is satisfied, a first process or a second process is executed; When the condition is not satisfied, the limited charging process is executed. The first process includes a process of executing the charging process by raising the upper limit SOC set in the limited charging process to a value higher than that in a case where the condition is not satisfied, the second process includes a process of executing the charging process without executing the limited charging process, the charging process includes a reference charging process of charging the power storage device in a state in which an SOC at a time when charging of the power storage device is started is lower than a second reference value that is less than the first reference value, so that an SOC at a time when charging of the power storage device is completed is higher than a first reference value, The condition includes a condition that a state in which the reference charging process is not executed continues for a threshold duration or longer from an end time of the reference charging process.

8. The estimation system according to claim 7 , wherein the threshold duration is shorter as the time that has elapsed since the start of use of the power storage device is shorter.

9. A power storage device; a processing device configured to execute a charging process for charging the power storage device and an estimation process for estimating a full charge capacity of the power storage device; the charging process includes a limited charging process of charging the power storage device so that the SOC of the power storage device does not exceed an upper limit SOC that is lower than a full charge SOC of the power storage device, the estimation process includes a process of estimating the full charge capacity by dividing an amount of charge charged to the power storage device by a ΔSOC indicating an increment of the SOC by the charging process, The processing device includes: When a condition indicating a decrease in the accuracy of estimating the full-charge capacity is satisfied, a first process or a second process is executed; When the condition is not satisfied, the limited charging process is executed. The first process includes a process of executing the charging process by raising the upper limit SOC set in the limited charging process to a value higher than that in a case where the condition is not satisfied, the second process includes a process of executing the charging process without executing the limited charging process, the estimation accuracy is determined according to an SOC at a start of charging the power storage device and an SOC at an end of charging the power storage device; The conditions include a condition that the estimation accuracy is equal to or less than a threshold accuracy.

10. The power storage device is mounted on a vehicle, the charging process is an external charging process in which the power storage device is charged using electric power from an electric power facility provided outside the vehicle, The estimation system according to claim 1 , wherein the charge amount is an amount of power charged from the power facility to the power storage device from a start of the external charging process to an end of the external charging process.

11. A vehicle comprising an estimation system according to any one of claims 1 to 10.

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