Battery control system, battery control method, and battery control program

Abstract

In the present invention, a data acquisition unit acquires battery data for a secondary battery that is included in a battery pack (30) mounted on an electric mobility vehicle (1). A state detection unit detects signs of abnormality in the secondary battery on the basis of the battery data. A notification control unit performs control such that a user of the electric mobility vehicle (1) receives a notification prompting a safety response when a sign of abnormality is detected in the secondary battery. A response status confirmation unit confirms the status of the response to the notification. A mode management unit shifts the battery pack (30) to a safety mode or a prohibited-use mode in accordance with the confirmation result for the status of the response.

Description

Battery control system, battery control method, and battery control program

[0001] The present disclosure relates to a battery control system, a battery control method, and a battery control program that control a battery pack mounted on an electric mobility vehicle.

[0002] Portable, detachable, and replaceable battery packs are used in electric mobility devices such as electric bicycles and electric motorcycles. Battery packs typically use assembled batteries with multiple cells connected in series. If the voltage balance between multiple series-connected cells is disrupted, the risk of overcharging or over-discharging increases. Many battery packs are equipped with a protective shutdown function that shuts down the battery if the potential difference between the cells exceeds several hundred millivolts.

[0003] Patent Document 1 discloses a mobile terminal device that is configured to prevent a low voltage alert (LVA) state, which calls for battery replacement, from occurring even when a battery remains fully usable if recovery action is taken after the battery voltage drops due to the continued flow of a large current and enters a low voltage alert state. Patent Document 1 describes a technology for preventing a low voltage alert from being issued to call for battery replacement when the battery is in a state where recovery is possible by stopping the large current, but does not disclose an alert that calls for battery replacement based on an irreversible abnormality or its precursor.

[0004] Patent Document 2 discloses a cooking appliance that counts the number of times a battery is low and issues an audio notification at a predetermined rate. Patent Document 2 aims to prevent the user from feeling inconvenienced by prompting the user to change the battery at appropriate intervals, but does not give much consideration to safety.

[0005] JP 2000-209787 A JP 2015-50786 A

[0006] The present disclosure has been made in view of these circumstances, and its purpose is to provide a technology that realizes a battery pack protection function that balances user convenience and safety.

[0007] In order to solve the above problems, a battery control system according to one aspect of the present disclosure includes a data acquisition unit that acquires battery data of a secondary battery included in a battery pack mounted on an electric mobility vehicle, a status detection unit that detects signs of an abnormality in the secondary battery based on the battery data, a notification control unit that controls the issuance of a notification to the user of the electric mobility vehicle to encourage safety measures when a sign of an abnormality in the secondary battery is detected, a response status confirmation unit that confirms the response status in response to the notification, and a mode management unit that transitions the battery pack to a safety mode or a prohibited use mode depending on the results of the response status confirmation.

[0008] Any combination of the above components, and conversion of the expression of the present disclosure into an apparatus, system, method, computer program, etc., are also valid aspects of the present disclosure.

[0009] According to the present disclosure, it is possible to realize a battery pack protection function that is both convenient for the user and safe.

[0010] Fig. 1 is a diagram for explaining a battery control system according to an embodiment. Fig. 2 is a diagram showing a configuration example of a battery pack according to an embodiment. Fig. 3 is a diagram showing a configuration example of a mobile terminal device according to an embodiment. Fig. 4 is a diagram showing a configuration example of a battery control system according to an embodiment. Fig. 5 is a diagram showing an example of a battery replacement message screen displayed on an operation display unit of a mobile terminal device. Fig. 6 is a flowchart showing the flow of remote control processing of a battery pack by a battery control system according to an embodiment.

[0011] FIG. 1 is a diagram illustrating a battery control system 10 according to an embodiment. The battery control system 10 according to the embodiment is a system for remotely controlling a battery pack 30 mounted on an electric bicycle 1. The battery control system 10 may be constructed, for example, on an in-house server installed in the in-house facility or data center of a provider that provides a remote control service for the battery pack 30. The battery control system 10 may also be constructed on a cloud server used based on a cloud service. The battery control system 10 may also be constructed on multiple servers distributed across multiple locations (data centers, in-house facilities). The multiple servers may be a combination of multiple in-house servers, a combination of multiple cloud servers, or a combination of an in-house server and a cloud server.

[0012] The electric bicycle 1 is equipped with a detachable, portable, and replaceable battery pack 30. The battery pack 30 is charged while attached to a charging slot of a charger (not shown). The charged battery pack 30 is removed from the charging slot by the user and attached to the attachment slot of the electric bicycle 1.

[0013] The battery pack 30 and the mobile terminal device 20 (hereinafter, assumed to be a smartphone) carried by the user are connected via short-range wireless communication, either directly or via a hand switch fixed to the handle. When connected via the hand switch, the battery pack 30 and the hand switch are connected via a wired connection, and the hand switch and the mobile terminal device 20 are connected via short-range wireless communication. Bluetooth (registered trademark), Wi-Fi (registered trademark), infrared communication, etc. can be used as short-range wireless communication. In the following, in this embodiment, it is assumed that BLE (Bluetooth Low Energy) is used as short-range wireless communication. BLE is an extended standard of Bluetooth and is a low-power short-range wireless communication standard using the 2.4 GHz band.

[0014] The mobile terminal device 20 can access the network 2 to which the battery control system 10 is connected. The mobile terminal device 20 can access the network 2 via a mobile phone network (4G / 5G) or Wi-Fi.

[0015] Network 2 is a general term for communication paths such as the Internet, dedicated lines, and VPNs (Virtual Private Networks), and the communication media and protocols are not important. Examples of communication media that can be used include wired LANs, wireless LANs, mobile phone networks, optical fiber networks, ADSL networks, and CATV networks. Examples of communication protocols that can be used include TCP (Transmission Control Protocol) / IP (Internet Protocol), UDP (User Datagram Protocol) / IP, and Ethernet (registered trademark).

[0016] 2 is a diagram showing an example of the configuration of a battery pack 30 according to an embodiment. The battery pack 30 includes a battery pack 31 and a battery management device 32. The battery pack 31 includes multiple cells E1-En connected in series. The number of cells connected in series is determined by the load specifications. The main loads of the electric bicycle 1 are the motor and the inverter.

[0017] The cells can be lithium-ion battery cells, nickel-metal hydride battery cells, lead battery cells, etc. In the following description, we will assume an example in which lithium-ion battery cells (nominal voltage: 3.6-3.7 V) are used. Note that in each series stage of cells, multiple cells may be connected in parallel to increase capacity.

[0018] A switch SW1 for switching between electrical continuity with the load or charger is inserted in the power line connecting the battery pack 31 and the load or charger. A semiconductor switch or a relay can be used as the switch SW1.

[0019] The battery management device 32 includes a measurement unit 33, a control unit 34, a wireless communication unit 35, an antenna 35a, and a non-volatile memory unit 36. The measurement unit 33 is configured with an AFE (Analog Front End) IC or an ASIC (Application Specific Integrated Circuit). The control unit 34 is configured with a microcontroller. The non-volatile memory unit 36 ​​can be an EEPROM (Electrically Erasable Programmable Read Only Memory) or a NAND flash memory.

[0020] The measurement unit 33 is connected to each node of the multiple cells E1-En connected in series by multiple voltage measurement lines, and measures the voltage of each cell E1-En by measuring the voltage between each two adjacent voltage measurement lines.

[0021] The measurement unit 33 includes a multiplexer and an A / D converter. The multiplexer outputs the voltages of the multiple cells E1-En to the A / D converter in a predetermined order. The A / D converter converts the analog voltages input from the multiplexer into digital values. The measurement unit 33 transmits the voltage values ​​of the cells E1-En, converted into digital values, to the control unit 34 via a serial communication interface.

[0022] The measurement unit 33 measures the current flowing through the battery pack 31. A shunt resistor Rs is connected to a power line connecting the battery pack 31 to a load or a charger. A differential amplifier (not shown) amplifies the voltage across the shunt resistor Rs and outputs it to an A / D converter in the measurement unit 33. The A / D converter converts the analog voltage indicating the current flowing through the battery pack 31, which is input from the differential amplifier, into a digital value. The measurement unit 33 transmits the current value converted into a digital value to the control unit 34 via a serial communication interface.

[0023] A temperature sensor T1 (e.g., a thermistor) is installed on the surface of the battery pack 31. A divided voltage between the temperature sensor T1 and a voltage dividing resistor (not shown) is input to a measurement unit 33. An A / D converter in the measurement unit 33 converts the input analog voltage indicating the temperature into a digital value. The measurement unit 33 transmits the converted digital temperature value to the control unit 34 via a serial communication interface.

[0024] The control unit 34 manages the states of the cells E1-En based on the voltage values ​​of the cells E1-En, the current values ​​flowing through the battery pack 31, and the temperature values ​​of the battery pack 31 received from the measurement unit 33. When the control unit 34 detects overcharging, overdischarging, overcurrent, high temperature abnormality, or low temperature abnormality, it sends a shut-off signal for the switch SW1 to the measurement unit 33 to turn off the switch SW1. When a voltage difference between the cells E1-En that exceeds a set value occurs, the control unit 34 determines that a cell balance abnormality has occurred, and sends a shut-off signal for the switch SW1 to the measurement unit 33 to turn off the switch SW1.

[0025] The control unit 34 estimates the SOC (State Of Charge) by combining the OCV method and the current integration method. The OCV method is a method for estimating the SOC based on the OCV, which is based on the measured cell voltage, and the SOC-OCV curve of the cell. The SOC-OCV curve of the cell is created in advance by the battery manufacturer based on characteristic tests and is registered in the control unit 34 at the time of shipment.

[0026] The current integration method is a method for estimating the SOC based on the OCV at the start of charging and discharging the cell and the integrated value of the measured current. With the current integration method, current measurement errors accumulate as the charging and discharging time increases. Therefore, it is preferable to use a weighted average of the SOC estimated by the current integration method and the SOC estimated by the OCV method.

[0027] The control unit 34 stores battery data including the cell voltage, current, temperature, and SOC of the battery pack 30 in the non-volatile memory unit 36 ​​at a predetermined storage period (for example, every one minute). As the cell voltage, the voltage values ​​of all the cells E1-En may be stored, or only the maximum cell voltage and the minimum cell voltage may be stored.

[0028] The wireless communication unit 35 performs signal processing for short-range wireless communication. The wireless communication unit 35 pairs with the mobile terminal device 20 and transmits battery data stored in the non-volatile memory unit 36 ​​via short-range wireless communication. In this embodiment, the wireless communication unit 35 is configured as a BLE module, and the antenna 35a is configured as a chip antenna or a pattern antenna built into the BLE module. Note that when the battery pack 30 and the mobile terminal device 20 are connected via a hand switch, the wireless communication unit 35 is omitted from the battery pack 30 and instead is mounted in the hand switch. The battery pack 30 and the mobile terminal device 20 are connected via a wired connection.

[0029] 3 is a diagram showing an example of the configuration of mobile terminal device 20 according to an embodiment. Mobile terminal device 20 is a terminal device carried by a user of electric bicycle 1. The user downloads an application program for managing electric bicycle 1 (hereinafter referred to as a bicycle app) from a distribution server to mobile terminal device 20 and installs it on mobile terminal device 20. The bicycle app is uploaded to the distribution server in advance, and the distribution server provides the bicycle app it manages to mobile terminal device 20 that accesses it via network 2.

[0030] The mobile terminal device 20 includes a GPS sensor 21, an inertial sensor 22, an operation display unit 23, a control unit 24, a recording medium 25, a first antenna 26a, and a second antenna 26b.

[0031] The GPS sensor 21 is an example of a GNSS (Global Navigation Satellite System) receiver, and detects the current location information of the mobile terminal device 20 in terms of latitude, longitude, and altitude, and outputs the detected location information to the control unit 24. Specifically, the GPS sensor 21 receives radio waves, including their respective transmission times, from a plurality of GPS satellites, and calculates the latitude, longitude, and altitude of the reception point based on the plurality of transmission times included in the plurality of received radio waves.

[0032] The inertial sensor 22 may be, for example, a three-axis gyro sensor and a three-axis acceleration sensor, which detect angular velocity and acceleration in the X, Y, and Z directions applied to the three-axis gyro sensor and the three-axis acceleration sensor and output the results to the control unit 24 .

[0033] The operation display unit 23 includes a touch panel display such as a liquid crystal display, an organic EL display, or a mini LED display, and displays an image input from the control unit 24. The operation display unit 23 also accepts operations from the user and outputs an operation signal to the control unit 24 according to the content of the user's operation.

[0034] The control unit 24 includes a first wireless communication unit 242a, a second wireless communication unit 242b, and a display control unit 243. The control unit 24 is realized by a combination of hardware resources and software resources, or by hardware resources alone. Examples of hardware resources that can be used include a CPU, ROM, RAM, GPU (Graphics Processing Unit), NPU (Neural Network Processing Unit), ASIC, FPGA (Field Programmable Gate Array), and other LSIs. Examples of software resources that can be used include programs such as an operating system, middleware, and applications.

[0035] The recording medium 25 is a large-capacity non-volatile recording medium, and is configured with a built-in flash memory (e.g., a NAND flash memory). Some models also allow for the addition of an external semiconductor memory card. Various programs and data are recorded on the recording medium 25.

[0036] The first wireless communication unit 242a uses the first antenna 26a to access the network 2 via a mobile phone network (4G / 5G) or Wi-Fi and connects to the battery control system 10. The second wireless communication unit 24ba uses the second antenna 26b to connect to the battery pack 30 via Bluetooth. The display control unit 243 can display on the operation display unit 23 a map on which the current position of the electric bicycle 1 detected by the GPS sensor 21 is superimposed.

[0037] When the user of the electric bicycle 1 launches the bicycle app on the portable terminal device 20 while the Bluetooth of the portable terminal device 20 is on, a connection is established between the second wireless communication unit 242b of the portable terminal device 20 and the wireless communication unit 35 of the battery pack 30.

[0038] When a connection is established between the battery pack 30 and the mobile terminal device 20, the control unit 34 of the battery pack 30 transmits the battery data stored in the non-volatile memory unit 36 ​​to the mobile terminal device 20 via the wireless communication unit 35. The mobile terminal device 20 transmits the battery data received from the second wireless communication unit 242b to the battery control system 10 via the network 2.

[0039] After transmitting the battery data to the battery control system 10 via the mobile terminal device 20, the control unit 34 of the battery pack 30 erases the transmitted battery data from the non-volatile memory unit 36. In this way, each time the bicycle app on the mobile terminal device 20 is launched, the battery data recorded between the previous launch and the current launch is transmitted to the battery control system 10.

[0040] 4 is a diagram showing an example of the configuration of a battery control system 10 according to an embodiment. The battery control system 10 includes a control unit 11, a storage unit 12, and a communication unit 13. The communication unit 13 is an external communication interface (e.g., a network interface card (NIC)) for connecting to the network 2 via a wired or wireless connection.

[0041] The control unit 11 includes a data acquisition unit 111, a status detection unit 112, a notification control unit 113, a response status confirmation unit 114, and a mode management unit 115. The functions of the control unit 11 can be realized by a combination of hardware resources and software resources, or by hardware resources alone. Examples of hardware resources that can be used include a CPU, ROM, RAM, GPU, NPU, ASIC, FPGA, and other LSIs. Examples of software resources that can be used include programs such as an operating system and applications.

[0042] The storage unit 12 includes a non-volatile recording medium such as a hard disk drive (HDD) or a solid state drive (SSD), and stores various data. The storage unit 12 includes a battery data holding unit 121.

[0043] The data acquisition unit 111 acquires battery data of the battery pack 30 from the mobile terminal device 20 via the network 2. The data acquisition unit 111 stores the acquired battery data in the battery data storage unit 121.

[0044] The state detection unit 112 reads out the battery data of the target battery pack 30 from the battery data storage unit 121, and based on the read out battery data, detects signs of an irreversible abnormality in the battery pack 30. An irreversible abnormality in the battery pack 30 includes, for example, an internal short circuit in a cell.

[0045] When lithium dentrite grows inside a lithium-ion battery cell and breaks through the separator, it short-circuits the positive and negative electrodes. If the lithium dentrite grows further and breaks through the separator to an even greater extent, the short-circuit between the positive and negative electrodes worsens. As the short-circuit worsens, the internal resistance decreases, creating a risk of the lithium-ion battery cell catching fire or emitting smoke.

[0046] When a micro-short circuit occurs within a cell due to metal contamination, separator misalignment, expansion of the positive and negative electrodes themselves, or lithium deposition due to use in harsh environments such as low temperatures, leakage current within the cell gradually drops the voltage of the cell where the micro-short circuit occurred, disrupting the voltage balance between multiple cells E1-En. If the rate at which the voltage of a cell where a micro-short circuit occurs is α [mV / hour], the rate at which the voltage difference ΔV between cells E1-En increases can also be defined as α [mV / hour]. α gradually increases over time depending on the progression of the internal micro-short circuit in the cell.

[0047] The voltage difference ΔV between cells E1-En is a value that indicates the voltage variation between cells E1-En and is defined as the difference between the maximum and minimum voltages of cells E1-En. Note that the voltage difference ΔV between cells E1-En may be defined as the difference between the average voltage and the minimum voltage of cells E1-En, or may be defined as the difference between the median voltage and the minimum voltage of cells E1-En.

[0048] In this embodiment, a mechanism is introduced that detects signs of an increase in the voltage difference ΔV between cells E1 and En and prompts replacement of battery pack 30 in the short circuit progression region (a safe region with a low risk of fire or smoke) before reaching the short circuit growth region (a dangerous region with a high risk of fire or smoke).

[0049] The status detection unit 112 compares the voltage difference ΔV between cells E1-En with a warning reference value for detecting entry into the short circuit progression region, and when the voltage difference ΔV between cells E1-En exceeds the warning reference value, it determines that a sign of an internal short circuit in the cell has occurred.

[0050] If a sign of an abnormality in the battery pack 30 (in the above example, a sign of an internal short circuit in a cell) is detected, the notification control unit 113 controls so that a notification is sent to the user of the electric bicycle 1 urging them to take safety measures. Specifically, the notification control unit 113 controls so that a message urging them to take safety measures is sent to the mobile terminal device 20, and the mobile terminal device 20 notifies the user of the electric bicycle 1 of the message. The notification control unit 113 controls so that a notification is sent to the user urging them to take at least one of the following safety measures: replace the battery pack 30, end use of the battery pack 30, or contact a support center.

[0051] The response status confirmation unit 114 confirms the response status to the notification. For example, when a battery replacement message including answer buttons of "Yes" and "No" is notified, the response status confirmation unit 114 receives "Yes," "No," or "Ignore" as the response status to the notification.

[0052] 5 is a diagram showing an example of a battery replacement message screen 23a displayed on the operation display unit 23 of the mobile terminal device 20. In accordance with the battery replacement message, the user presses the "Yes" button 23b if they want to replace the battery pack 30, or presses the "No" button 23c if they do not want to replace it yet.

[0053] The mode management unit 115 manages the mode of the battery pack 30 depending on the confirmation result of the user's response status. After a notification urging a safety response is sent to the mobile terminal device 20, if the safety response in response to the notification is not confirmed, the mode management unit 115 transitions the battery pack 30 from the normal mode to the safety mode. After transitioning to the safety mode, if the safety response in response to the notification urging a safety response is not confirmed, the mode management unit 115 transitions the battery pack 30 from the safety mode to the use prohibited mode. The safety mode is a mode in which the battery pack 30 is used safely by restricting the capabilities or functions of the battery pack 30.

[0054] The mode management unit 115 may transition the battery pack 30 from normal mode to safety mode at the same time as a notification urging safety measures is sent to the mobile terminal device 20, and then transition from safety mode to prohibited use mode depending on the results of checking the response status to the notification.

[0055] In addition, after a notification urging safety measures is sent to the mobile terminal device 20, the mode management unit 115 may transition the battery pack 30 from normal mode to safety mode based on the results of checking the response status to the notification, and may further transition from safety mode to prohibited use mode based on the results of checking the response status thereafter.

[0056] Furthermore, after a notification urging safety measures is sent to the mobile terminal device 20, the mode management unit 115 may, based on the results of checking the response status to the notification, transition the battery pack 30 to safety mode if it is possible to transition to safety mode, or transition it to prohibited use mode if it is not possible to transition to safety mode.

[0057] The mode management unit 115 transitions the battery pack 30 from the normal mode to the safety mode or from the safety mode to the use prohibition mode when a predetermined time has elapsed since the notification urging safety measures was first transmitted to the mobile terminal device 20, or when the number of notifications urging safety measures reaches or exceeds a predetermined number. After the notification urging safety measures is transmitted to the mobile terminal device 20, the mode management unit 115 continuously monitors the battery data of the target battery pack 30, and transitions the battery pack 30 to the use prohibition mode if the state of the battery pack 30 is at a danger level.

[0058] For example, in the safety mode, the mode management unit 115 limits the upper limit of the SOC that can be charged to the battery pack 30. For example, in the safety mode, the upper limit of the SOC that can be charged to the battery pack 30 is limited to 75% or 50%. In this case, the usable discharge capacity of the battery pack 30 is reduced to ¾ or ½ compared to the normal mode. The mode management unit 115 transmits the upper limit of the chargeable SOC to the control unit 34 of the battery pack 30 via the mobile terminal device 20. When the SOC of the battery pack 31 reaches the upper limit received from the battery control system 10 during charging of the battery pack 31, the control unit 34 forcibly terminates charging. Note that the upper limit of the chargeable SOC may be limited by the voltage of the battery pack 31 instead of the SOC.

[0059] Furthermore, in the safety mode, the mode management unit 115 can set an upper limit on the amount of time that the battery pack 30 can be charged in a certain period of time. For example, in the safety mode, the amount of time that can be charged in one day can be limited to two hours or five hours. The mode management unit 115 transmits the upper limit value of the amount of time that can be charged in one day to the control unit 34 of the battery pack 30 via the mobile terminal device 20. When charging the battery pack 31, the control unit 34 forcibly terminates charging if the charging time of the battery pack 31 in one day reaches the upper limit value received from the battery control system 10.

[0060] Furthermore, in safety mode, the mode management unit 115 can limit the upper limit of the output current or output power that can be discharged from the battery pack 30. For example, in safety mode, the upper limit of the dischargeable output current or output power is limited to 75% or 50% of the upper limit of the dischargeable output current or output power in normal mode. The mode management unit 115 transmits the upper limit of the output current or output power to the control unit 34 of the battery pack 30 via the mobile terminal device 20. The control unit 34 transmits the upper limit of the output current or output power received from the battery control system 10 to the ECU (not shown) of the electric bicycle 1. The ECU of the electric bicycle 1 sets the upper limit of the output current or output power in the inverter or DC / DC converter of the electric bicycle 1.

[0061] In the use prohibition mode, the mode management unit 115 prohibits charging and discharging of the battery pack 30. The mode management unit 115 transmits a use prohibition notification to the control unit 34 of the battery pack 30 via the mobile terminal device 20. When the control unit 34 receives the use prohibition notification from the battery control system 10, it transmits a shut-off signal for the switch SW1 to the measurement unit 33 to permanently turn off the switch SW1.

[0062] 6 is a flowchart showing the flow of the remote control process of the battery pack 30 by the battery control system 10 according to the embodiment. The status detection unit 112 detects signs of an abnormality in the battery pack 30 based on the battery data of the target battery pack 30 (S10). The notification control unit 113 transmits a message (hereinafter referred to as a battery replacement message) to the mobile terminal device 20 prompting the user to replace the battery (S11). The control unit 24 of the mobile terminal device 20 displays the received battery replacement message on the operation / display unit 23. If the user selects "Yes" (Y in S12), the control unit 24 of the mobile terminal device 20 transmits "Yes" to the battery control system 10 as the response status. The notification control unit 113 of the battery control system 10 transmits a message (hereinafter referred to as a battery replacement procedure message) indicating the battery replacement procedure to the mobile terminal device 20, and the control unit 24 of the mobile terminal device 20 displays the received battery replacement procedure message on the operation / display unit 23 (S23).

[0063] If the user does not select "Yes" in response to the battery replacement message (N in S12), the mode management unit 115 determines whether the number of times the battery replacement message has been notified is equal to or greater than a predetermined number (S13). If the number of times is less than the predetermined number (N in S13), the mode management unit 115 determines whether a predetermined time or more has passed since the battery replacement message was first sent (S14). If the predetermined time or more has not passed (N in S14), after waiting 24 hours (S15), the notification control unit 113 resends the battery replacement message to the mobile terminal device 20 (S11).

[0064] If the number of times the battery replacement message has been sent is equal to or greater than a predetermined number (Y in S13), or if a predetermined amount of time has passed since the initial transmission of the battery replacement message (Y in S14), the mode management unit 115 determines that continued use of the battery pack 30 is at a warning level and transitions the battery pack 30 to safety mode (S16). The notification control unit 113 retransmits the battery replacement message to the mobile terminal device 20 (S17). The control unit 24 of the mobile terminal device 20 displays the received battery replacement message on the operation and display unit 23. If the user selects "Yes" (Y in S18), the control unit 24 of the mobile terminal device 20 transmits "Yes" as the response status to the battery control system 10. The notification control unit 113 of the battery control system 10 transmits a battery replacement procedure message to the mobile terminal device 20, and the control unit 24 of the mobile terminal device 20 displays the received battery replacement procedure message on the operation and display unit 23 (S23).

[0065] If the user does not select "Yes" in response to the presented battery replacement message (N in S18), the mode management unit 115 determines whether or not a predetermined time has elapsed since the battery replacement message was first transmitted after switching to the safety mode (S19). If the predetermined time has not elapsed (N in S19), the mode management unit 115 determines whether or not a monitoring value based on battery data of the battery pack 30 has exceeded a safety reference value (S20). In the above example, the monitoring value is the voltage difference ΔV between cells E1 and En, and the safety reference value is a reference value for detecting entry into a short-circuit growth region (a dangerous region with a high risk of fire or smoke).

[0066] If the monitored value does not exceed the safety standard value (N of S20), after waiting for 24 hours (S21), the notification control unit 113 will resend the battery replacement message to the mobile terminal device 20 (S17).

[0067] After transitioning to the safety mode, if a predetermined time or more has passed since the battery replacement message was first sent (Y in S19), or if the monitored value exceeds the safety standard value (Y in S20), the mode management unit 115 determines that continued use of the battery pack 30 is at a dangerous level, and transitions the battery pack 30 to the prohibited use mode (S22).

[0068] As described above, according to this embodiment, when an unsafe condition is detected based on collected battery data, a notification is sent to the user recommending that the battery pack 30 be replaced, the device is remotely controlled to switch to safety mode, and after a certain period of time has passed, the device is remotely controlled to switch to prohibited use mode. This gives the user time to prepare in advance before the battery pack 30 becomes unusable. The user can avoid a situation in which the electric bicycle 1 suddenly stops electric travel due to a protective stop while traveling in electric power. In this way, this embodiment can achieve a battery pack 30 protection function that combines user convenience and safety.

[0069] The present disclosure has been described above based on the embodiments. The embodiments are merely examples, and it will be understood by those skilled in the art that various modifications are possible in the combination of the respective components and processing steps, and that such modifications are also within the scope of the present disclosure.

[0070] In the above-described embodiment, an internal short circuit of a cell is used as an example of an irreversible abnormality of the battery pack 30. Other irreversible abnormalities of the battery pack 30 include an increase in external resistance (e.g., wiring resistance, contact resistance) due to mechanical factors external to the cell. The state detection unit 112 monitors the ohmic resistance (= ΔV / ΔI) of each cell E1-En. If the ohmic resistance continues to increase after eliminating fluctuation factors due to the internal state of the cell (e.g., temperature, SOC, SOH (State of Health), etc.), mechanical deterioration of the wiring or terminals may be progressing. The state detection unit 112 determines that a sign of mechanical deterioration has occurred when the ohmic resistance exceeds a warning reference value after eliminating fluctuation factors due to the internal state of the cell. If the ohmic resistance exceeds a danger reference value after eliminating fluctuation factors due to the internal state of the cell, the mode management unit 115 determines that continued use of the battery pack 30 is at a dangerous level and transitions the battery pack 30 to a prohibited use mode.

[0071] In the above-described embodiment, the electric bicycle 1 is assumed to be the electric mobility device equipped with the battery pack 30, but it may also be an electric motorcycle, an electric kick scooter, or a micro EV. In the above-described embodiment, the mobile terminal device 20 is assumed to be a smartphone, but it may also be any device that can access the network 2, such as a cycle computer or a smart watch.

[0072] The control function of the battery pack 30 executed by the battery control system 10 described above may be incorporated into the control unit 34 in the battery pack 30. In this case, the nonvolatile memory unit 36 ​​needs to be a large-capacity nonvolatile memory unit for storing battery data.

[0073] The embodiment may be specified by the following items.

[0074] [Item 1] A battery control system (10) comprising: a data acquisition unit (111) that acquires battery data of a secondary battery (31) included in a battery pack (30) mounted on an electric mobility (1); a status detection unit (112) that detects signs of an abnormality in the secondary battery (31) based on the battery data; a notification control unit (113) that, when a sign of an abnormality in the secondary battery (31) is detected, controls to issue a notification urging a user of the electric mobility (1) to take safety measures; a response status confirmation unit (114) that confirms the response status in response to the notification; and a mode management unit (115) that transitions the battery pack (30) to a safety mode or a use prohibited mode depending on the confirmation result of the response status. This makes it possible to achieve both convenience for the user and safety. [Item 2] The battery control system (10) according to Item 1, wherein the notification prompting the safety action is sent to a terminal device (20) accessible to the user, and the mode management unit (115) transitions to the safety mode; and if a safety action in response to the notification is not confirmed after transitioning to the safety mode, the mode management unit (115) transitions to the use prohibition mode. This gives the user time to prepare in advance before the battery pack (30) becomes unusable. [Item 3] The battery control system (10) according to Item 1, wherein the notification prompting the safety action is sent to a terminal device (20) accessible to the user, and if a safety action in response to the notification is not confirmed, the mode management unit (115) transitions to the safety mode; and if a safety action in response to the notification is not confirmed after transitioning to the safety mode, the mode management unit (115) transitions to the use prohibition mode. This gives the user time to prepare in advance before the battery pack (30) becomes unusable. [Item 4] The battery control system (10) according to any one of Items 1 to 3, wherein the mode management unit (115) transitions the battery pack (30) from a normal mode to the safety mode or from the safety mode to the use prohibition mode when the number of notifications urging the battery pack to take the safety action reaches or exceeds a predetermined number.This allows the user to be adequately notified before the battery pack (30) is switched to the safety mode or the use prohibition mode. [Item 5] The battery control system (10) according to any one of Items 1 to 3, wherein the mode management unit (115) switches the battery pack (30) from the normal mode to the safety mode or from the safety mode to the use prohibition mode when a predetermined time has elapsed since the notification prompting safety measures was first transmitted to the terminal device (20) accessible by the user. This allows the user to be given a sufficient grace period before the battery pack (30) is switched to the safety mode or the use prohibition mode. [Item 6] The battery control system (10) according to Item 1, wherein the mode management unit (115) switches the battery pack (30) to the use prohibition mode when the state of the secondary battery (31) is at a dangerous level. This ensures safety. [Item 7] The battery control system (10) according to Item 1, wherein the notification control unit (113) controls to issue a notification to the user urging at least one of replacing the battery pack (30), ending use of the battery pack (30), and contacting a support center as a safety measure. This allows the user to be prompted to take appropriate action in response to a sign of an abnormality in the secondary battery (31). [Item 8] The battery control system (10) according to Item 1, wherein the mode management unit (115), in the safety mode, limits an upper limit on the SOC (State of Charge) that can be charged to the battery pack (30) or sets an upper limit on the time that can be charged within a certain period. This reduces the burden on the battery pack (30) and improves safety. [Item 9] The battery control system (10) according to Item 1, wherein the mode management unit (115), in the safety mode, limits an upper limit on the output current or output power that can be discharged from the battery pack (30). This reduces the burden on the battery pack (30) and improves safety.[Item 10] A battery control method comprising the steps of: acquiring battery data of a secondary battery (31) included in a battery pack (30) mounted on an electric mobility (1); detecting a sign of an abnormality in the secondary battery (31) based on the battery data; controlling to issue a notification to a user of the electric mobility (1) urging the user to take safety measures when a sign of an abnormality in the secondary battery (31) is detected; confirming a response status to the notification; and transitioning the battery pack (30) to a safety mode or a use prohibited mode depending on the confirmation result of the response status. This makes it possible to achieve both convenience for the user and safety. [Item 11] A battery control program that causes a computer to execute the following processes: a process of acquiring battery data of a secondary battery (31) included in a battery pack (30) mounted on an electric mobility (1); a process of detecting a sign of an abnormality in the secondary battery (31) based on the battery data; a process of controlling to issue a notification urging a user of the electric mobility (1) to take safety measures when a sign of an abnormality in the secondary battery (31) is detected; a process of confirming a response status to the notification; and a process of transitioning the battery pack (30) to a safety mode or a use prohibited mode depending on the confirmation result of the response status. This makes it possible to achieve both convenience for the user and safety.

[0075] The present invention can be used to protect a battery pack mounted on an electric mobility vehicle.

[0076] REFERENCE SIGNS LIST 1 Electric bicycle, 2 Network, 30 Battery pack, 31 Assembled battery, 32 Battery management device, 33 Measurement unit, 34 Control unit, 35 Wireless communication unit, 35a Antenna, 36 Non-volatile memory unit, E1-En Cell, Rs Shunt resistor, T1 Temperature sensor, SW1 Switch, 10 Battery control system, 11 Control unit, 111 Data acquisition unit, 112 Status detection unit, 113 Notification control unit, 114 Response status confirmation unit, 115 Mode management unit, 12 Memory unit, 121 Battery data retention unit, 13 Communication unit, 20 Portable terminal device, 21 GPS sensor, 22 Inertial sensor, 23 Operation display unit, 24 Control unit, 242a First wireless communication unit, 242b Second wireless communication unit, 243 Display control unit, 25 recording medium, 26a first antenna, 26b second antenna.

Claims

1. A battery control system comprising: a data acquisition unit that acquires battery data of a secondary battery included in a battery pack mounted on an electric mobility; a status detection unit that detects signs of an abnormality in the secondary battery based on the battery data; a notification control unit that controls the issuance of a notification to encourage a user of the electric mobility to take safety measures when a sign of an abnormality in the secondary battery is detected; a response status confirmation unit that confirms the response status in response to the notification; and a mode management unit that transitions the battery pack to a safety mode or a prohibited use mode depending on the confirmation result of the response status.

2. The battery control system of claim 1, wherein the notification urging the user to take safety measures is sent to a terminal device that the user can refer to, and the mode management unit transitions to the safety mode, and if the safety measures taken in response to the notification are not confirmed after transitioning to the safety mode, the mode management unit transitions to the prohibited use mode.

3. The battery control system of claim 1, wherein, after the notification urging safety measures is sent to a terminal device that the user can refer to, if safety measures in response to the notification are not confirmed, the mode management unit transitions to the safety mode, and, after transitioning to the safety mode, if safety measures in response to the notification are not confirmed, the mode management unit transitions to the prohibited use mode.

4. A battery control system as described in any one of claims 1 to 3, wherein the mode management unit transitions the battery pack from normal mode to the safety mode, or from the safety mode to the prohibited use mode, when the number of notifications urging safety measures reaches a predetermined number or more.

5. A battery control system as described in any one of claims 1 to 3, wherein the mode management unit transitions the battery pack from normal mode to the safety mode, or from the safety mode to the prohibited use mode, when a predetermined time has elapsed since the notification urging safety measures was first sent to a terminal device that the user can refer to.

6. The battery control system according to claim 1, wherein the mode management unit switches the battery pack to the use prohibition mode when the state of the secondary battery is at a dangerous level.

7. The battery control system according to claim 1, wherein the notification control unit controls the user to receive a notification urging the user to take at least one of the following safety measures: replace the battery pack, stop using the battery pack, or contact a support center.

8. The battery control system according to claim 1, wherein, in the safety mode, the mode management unit limits the upper limit of the SOC (State Of Charge) that can be charged to the battery pack, or sets an upper limit on the amount of time that can be charged within a certain period of time.

9. The battery control system according to claim 1, wherein the mode management unit limits an upper limit of the output current or output power that can be discharged from the battery pack in the safety mode.

10. A battery control method comprising the steps of: acquiring battery data of a secondary battery included in a battery pack mounted on an electric mobility; detecting signs of an abnormality in the secondary battery based on the battery data; controlling the system so that, when a sign of an abnormality in the secondary battery is detected, a notification is sent to the user of the electric mobility urging them to take safety measures; confirming the response status to the notification; and transitioning the battery pack to a safety mode or a prohibited use mode depending on the confirmation result of the response status.

11. A battery control program that causes a computer to execute the following processes: a process of acquiring battery data of a secondary battery included in a battery pack installed in an electric mobility; a process of detecting signs of an abnormality in the secondary battery based on the battery data; a process of controlling so that, if signs of an abnormality in the secondary battery are detected, a notification is sent to the user of the electric mobility urging them to take safety measures; a process of confirming the response status to the notification; and a process of transitioning the battery pack to a safety mode or a prohibited use mode depending on the results of the confirmation of the response status.

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