Battery control system, battery pack, small electric vehicle, battery control method, and computer program

Abstract

To reduce a communication load and a calculation load of a vehicle control device.SOLUTION: A battery control system 20 for a small electric vehicle 1 comprises a plurality of battery packs 21. The plurality of battery packs 21 includes: a battery pack 21 having the authority to output electric power for driving an electric motor 32 that generates drive power for making the small electric vehicle 1 travel; and a battery pack 21 not having the authority. A plurality of control devices 120 of the plurality of battery packs 21 mutually transmits and receives internal information related to states of the battery packs 21. At least one of the plurality of control devices 120 changes the battery pack 21 having the authority out of the plurality of battery packs 21, on the basis of the internal information.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a battery control system, a battery pack, a small electric vehicle, a battery control method, and a computer program.

Background Art

[0002] As one of small electric vehicles that run using an electric motor as a drive source, an electric assist bicycle that assists the force applied by a rider to a pedal with an electric motor is known (see, for example, Patent Document 1). The electric motor generates a driving force by being supplied with electric power from a battery pack mounted on the vehicle body. In an electric assist bicycle, a driving force corresponding to the human power applied by the user to the pedal is generated in the electric motor, and for example, the burden on the user when traveling on a slope or when carrying luggage can be reduced.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In order to increase the distance that an electric assist bicycle can travel while the electric motor generates an assisting force, there may be cases where a plurality of battery packs are mounted on the electric assist bicycle. In this case, a vehicle control device (for example, an MCU (Motor Control Unit)) that controls the running of the electric assist bicycle manages these plurality of battery packs. The vehicle control device monitors the states of the plurality of battery packs and performs control such as switching the battery pack that supplies electric power to the electric motor. For this reason, in an electric assist bicycle equipped with a plurality of battery packs, there is a problem that the communication load and the calculation load of the vehicle control device increase.

[0005] It is required to reduce the communication load and the calculation load of the vehicle control device. [Means for solving the problem]

[0006] This specification discloses battery control systems, battery packs, small electric vehicles, battery control methods, and computer programs as described in the following sections.

[0007] [Item 1] A battery control system for small electric vehicles, Equipped with multiple battery packs, Each of the aforementioned plurality of battery packs is A battery module having multiple battery cells, A control device for controlling the discharge of the battery module, the control device having an internal control device that outputs internal information relating to the state of the battery pack, A battery housing that houses the battery module and the control device inside, Equipped with, The plurality of battery packs include battery packs that have the authority to output power to drive an electric motor that generates the driving force to move the small electric vehicle, and battery packs that do not have the authority. The multiple control devices of the multiple battery packs transmit and receive the internal information to each other. A battery control system in which at least one of the plurality of control devices changes the authorized battery pack among the plurality of battery packs based on the internal information.

[0008] According to one embodiment of the present invention, internal information is transmitted and received between multiple battery packs, and the authorized battery pack is changed based on the internal information. The vehicle control device that controls the vehicle's operation no longer needs to monitor the status of multiple battery packs and perform the process of changing the authorized battery pack, thereby reducing the communication load and computational load of the vehicle control device.

[0009] [Item 2] The aforementioned internal information is, Survival information to confirm whether the aforementioned battery pack is operating, Information indicating the presence or absence of abnormalities, Information indicating whether or not the aforementioned authority exists, Information indicating the upper limit of the output current, Information indicating remaining battery capacity, Information indicating battery capacity, A battery control system as described in item 1, including one or more of the following:

[0010] This allows multiple battery packs to monitor each other's status.

[0011] [Item 3] The plurality of battery packs include a first battery pack which is the authorized battery pack, and a second battery pack which is the unauthorized battery pack. When the control device of the first battery pack determines that the first battery pack is in a predetermined state, it outputs a command to the second battery pack indicating that it will transfer the authority to the second battery pack. The battery control system according to item 1 or 2, wherein the control device of the second battery pack is configured to set the second battery pack as the authorized battery pack.

[0012] When the first battery pack is in a predetermined state (for example, when the upper limit of the output current is below a threshold), the above authority is transferred from the first battery pack to the second battery pack. This ensures a stable power supply to the vehicle.

[0013] [Item 4] The aforementioned predetermined state is, A state in which the upper limit of the output current is below the threshold, The state in which the output voltage is below the threshold, When the remaining battery capacity is below a threshold, A state in which the temperature is above a threshold, The battery control system according to item 3, which is at least one of them.

[0014] When the first battery pack is in the above state, by transferring the above authority from the first battery pack to the second battery pack, a stable power supply to the vehicle can be continued.

[0015] [Item 5] The plurality of battery packs include a battery pack having the authority and two or more battery packs not having the authority. The control device of the battery pack having the authority When it is determined that the battery pack having the authority is in a predetermined state Determine a transfer target battery pack to which the authority is to be transferred from among two or more battery packs not having the authority. Output a command indicating that the authority is to be transferred to the transfer target battery pack to the transfer target battery pack. The control device of the transfer target battery pack sets the transfer target battery pack as a battery pack having the authority. The battery control system according to item 1 or 2.

[0016] When the battery pack having the authority is in a predetermined state (for example, a state where the upper limit value of the outputable current is less than the threshold value), transfer the above authority to another battery pack. Thereby, a stable power supply to the vehicle can be continued.

[0017] [Item 6] The predetermined state is A state where the upper limit value of the outputable current is less than the threshold value, A state where the output voltage is less than the threshold value, A state where the remaining battery capacity is less than the threshold value, A state where the temperature is equal to or higher than the threshold value, The battery control system according to item 5, which is at least one of them.

[0018] If a battery pack with the above authority is in the above state, it can continue to supply stable power to the vehicle by transferring the above authority to another battery pack.

[0019] [Item 7] Prior to the transfer of the said authority, the control device of the battery pack having said authority is: A battery control system according to item 5 or 6, which determines the transfer recipient battery pack from among the two or more battery packs that do not have the authority, based on the internal information of each of the two or more battery packs that do not have the authority.

[0020] This allows the above rights to be transferred to the appropriate battery pack.

[0021] [Item 8] Prior to the transfer of the said authority, the control device of the battery pack having said authority is: The battery control system described in item 7, which determines the battery pack to be transferred from among two or more battery packs that do not possess the aforementioned authority, the battery pack with the largest remaining battery capacity or the battery pack with the largest maximum output current limit.

[0022] This allows the aforementioned authority to be transferred to a battery pack capable of supplying greater power to the electric motor.

[0023] [Item 9] Prior to the transfer of the said authority, the control device of the battery pack having said authority is: A battery control system according to item 5 or 6, which determines the recipient battery pack from among the two or more battery packs that do not have the aforementioned authority, based on unique information assigned to each of the two or more battery packs that do not have the aforementioned authority.

[0024] This allows for the determination of the recipient battery pack with a simple process.

[0025] [Item 10] The aforementioned internal information includes the survival information, The plurality of battery packs include a first battery pack which is the authorized battery pack, and a second battery pack which is the unauthorized battery pack. The battery control system according to item 2, wherein the control device of the second battery pack is unable to receive the survival information from the first battery pack, and sets the second battery pack to the authorized battery pack.

[0026] If the first battery pack, which has the above authority, is not operating, the second battery pack will be set to the battery pack with the above authority. This will ensure a stable power supply to the vehicle.

[0027] [Item 11] The aforementioned internal information includes the survival information, The plurality of battery packs include the authorized battery pack and two or more battery packs that do not have the authorized, At least one of the control devices of two or more battery packs that do not have the aforementioned authority, If the survival information cannot be received from the battery pack having the aforementioned authority, From among two or more battery packs that do not possess the aforementioned authority, determine which battery pack is to be granted the aforementioned authority. The battery control system described in item 2, wherein the control device of the target battery pack is set to the authorized battery pack.

[0028] If the battery pack with the above permissions is not operating, another battery pack will be set to the battery pack with the above permissions. This will ensure a stable power supply to the vehicle.

[0029] [Item 12] At least one of the control devices of two or more battery packs that do not have the aforementioned authority, A battery control system according to item 11, which determines the target battery pack from among two or more battery packs that do not have the authority, based on the internal information of each of the two or more battery packs that do not have the authority.

[0030] This allows the appropriate battery pack to be granted the above permissions.

[0031] [Item 13] At least one of the control devices of two or more battery packs that do not have the aforementioned authority, The battery control system described in item 12, which determines the target battery pack to be the battery pack with the largest remaining battery capacity or the battery pack with the largest upper limit of the output current among two or more battery packs that do not have the aforementioned authority.

[0032] This allows the aforementioned authority to be granted to a battery pack capable of supplying greater power to the electric motor.

[0033] [Item 14] At least one of the control devices of two or more battery packs that do not have the aforementioned authority, A battery control system according to item 11, which determines the target battery pack from among two or more battery packs that do not have the aforementioned authority, based on unique information assigned to each of the two or more battery packs that do not have the aforementioned authority.

[0034] This allows for a simple process to determine which battery packs will be granted the above permissions.

[0035] [Item 15] The battery control system according to any one of items 1 to 14, wherein the type of information contained in the internal information transmitted and received between the plurality of battery packs is the same among the plurality of battery packs.

[0036] This allows multiple battery packs to monitor each other's status without any master-slave relationship.

[0037] [Item 16] The battery control system according to any one of items 1 to 15, wherein the plurality of battery packs are detachable from the small electric vehicle.

[0038] This allows the battery pack to be charged while removed from the vehicle. It also allows for adjustment of the number of battery packs installed in the vehicle.

[0039] [Item 17] A small electric vehicle equipped with a battery control system as described in any of items 1 through 16.

[0040] This makes it possible to realize a compact electric vehicle with reduced communication and computational load on the vehicle control system.

[0041] [Item 18] The aforementioned small electric vehicle is an electric assist bicycle, as described in item 17.

[0042] This makes it possible to realize an electric assist bicycle with reduced communication and computational load on the vehicle control unit (MCU).

[0043] [Item 19] A battery control method for controlling multiple battery packs for a small electric vehicle, which is executed by multiple computers, The plurality of battery packs include battery packs that have the authority to output power to drive an electric motor that generates the driving force to move the small electric vehicle, and battery packs that do not have the authority. Each of the aforementioned battery packs outputs internal information regarding the state of its own battery pack. The aforementioned battery control method is The internal information is transmitted and received between the plurality of battery packs. Based on the internal information transmitted and received between the plurality of battery packs, the battery pack with the authority among the plurality of battery packs is changed. A battery control method, including...

[0044] According to one embodiment of the present invention, internal information is transmitted and received between multiple battery packs, and the authorized battery pack is changed based on the internal information. The vehicle control device that controls the vehicle's operation no longer needs to monitor the status of multiple battery packs and perform the process of changing the authorized battery pack, thereby reducing the communication load and computational load of the vehicle control device.

[0045] [Item 20] A computer program that causes multiple computers to perform a process to control multiple battery packs for a small electric vehicle, The plurality of battery packs include battery packs that have the authority to output power to drive an electric motor that generates the driving force to move the small electric vehicle, and battery packs that do not have the authority. Each of the aforementioned battery packs outputs internal information regarding the state of its own battery pack. The aforementioned computer program, The internal information is transmitted and received between the plurality of battery packs. Based on the internal information transmitted and received between the plurality of battery packs, the battery pack with the authority among the plurality of battery packs is changed. A computer program that causes the aforementioned multiple computers to execute it.

[0046] According to one embodiment of the present invention, internal information is transmitted and received between multiple battery packs, and the authorized battery pack is changed based on the internal information. The vehicle control device that controls the vehicle's operation no longer needs to monitor the status of multiple battery packs and perform the process of changing the authorized battery pack, thereby reducing the communication load and computational load of the vehicle control device.

[0047] [Item 21] A battery pack for small electric vehicles, A battery module having multiple battery cells, A control device for controlling the discharge of the battery module, A battery housing that houses the battery module and the control device inside, Equipped with, The aforementioned small electric vehicle is equipped with multiple battery packs, including the aforementioned battery pack. Each of the aforementioned battery packs outputs internal information regarding the state of its own battery pack. The plurality of battery packs include battery packs that have the authority to output power to drive an electric motor that generates the driving force to move the small electric vehicle, and battery packs that do not have the authority. The aforementioned multiple battery packs mutually transmit and receive the internal information, The control device changes the authorized battery pack among the plurality of battery packs based on the internal information transmitted and received between the plurality of battery packs.

[0048] According to one embodiment of the present invention, internal information is transmitted and received between multiple battery packs, and the authorized battery pack is changed based on the internal information. The vehicle control device that controls the vehicle's operation no longer needs to monitor the status of multiple battery packs and perform the process of changing the authorized battery pack, thereby reducing the communication load and computational load of the vehicle control device. [Effects of the Invention]

[0049] According to one embodiment of the present invention, internal information is transmitted and received between multiple battery packs, and based on this internal information, the battery pack authorized to output power for driving an electric motor is changed. The vehicle control device that controls the vehicle's movement no longer needs to monitor the status of multiple battery packs and perform the process of changing the authorized battery pack, thereby reducing the communication load and computation load of the vehicle control device. [Brief explanation of the drawing]

[0050] [Figure 1] This is a right side view showing an electric assist bicycle 1 according to an embodiment of the present invention. [Figure 2] This is a block diagram showing an example of the hardware configuration of a battery pack 21 according to an embodiment of the present invention. [Figure 3] This figure shows how to attach and detach the battery pack 21a to the electric assist bicycle 1 according to an embodiment of the present invention. [Figure 4] This is a block diagram showing an example of the hardware configuration of a drive unit 30 according to an embodiment of the present invention. [Figure 5] This is a block diagram showing a battery control system 20 according to an embodiment of the present invention. [Figure 6] This flowchart shows an example of a process for modifying a battery pack 21 authorized according to an embodiment of the present invention. [Figure 7] This flowchart shows another example of a process for modifying a battery pack 21 authorized according to an embodiment of the present invention. [Figure 8] This is a block diagram showing another example of the battery control system 20 according to an embodiment of the present invention. [Figure 9] This flowchart shows yet another example of a process for modifying a battery pack 21 authorized according to an embodiment of the present invention. [Figure 10] This flowchart shows yet another example of a process for modifying a battery pack 21 authorized according to an embodiment of the present invention. [Modes for carrying out the invention]

[0051] Embodiments of the present invention will be described below with reference to the drawings. In the description of the embodiments, similar components will be denoted by the same reference numerals, and their descriptions will be omitted if they are redundant. The numerals F, Re, U, and D in the drawings represent front, back, top, and bottom, respectively.

[0052] In the following description of embodiments, an electric assist bicycle is given as an example of a small electric vehicle, but the small electric vehicle in the embodiment is not limited to an electric assist bicycle. Small electric vehicles include personal mobility devices. Small electric vehicles may be, for example, electric two-wheeled vehicles, electric three-wheeled vehicles, electric wheelchairs, electric assist wheelchairs, PLEV (Personal Light Electric Vehicles), etc. Electric two-wheeled vehicles include parallel two-wheeled vehicles. Electric wheelchairs include handlebar-type electric wheelchairs. The electric assist bicycle exemplified below is a two-wheeled electric assist bicycle, but it may also be a three-wheeled electric assist bicycle. The following embodiments are illustrative, and the present invention is not limited to the embodiments described below.

[0053] [Electric-assisted bicycle] Figure 1 is a right side view showing the electric assist bicycle 1 according to this embodiment.

[0054] The electric assist bicycle 1 has a frame 2 that extends in the front-to-back direction. The frame 2 includes a head pipe 11, a down tube 12, a top tube 14, a seat tube 16, a chain stay 18, a seat stay 19, and a bracket 26. The head pipe 11 is located at the front end of the frame 2. The handlebar column 13 is rotatably inserted into the head pipe 11. The handlebars 4 are fixed to the handlebar column 13. The handlebars 4 are equipped with a meter unit 5 that displays various information about the electric assist bicycle 1. A headlamp 8 is provided on the front part of the handlebars 4.

[0055] The front fork 15 is fixed to the lower end of the handlebar column 13. The lower end of the front fork 15 rotatably supports the front wheel 6, which is the steering wheel.

[0056] The down tube 12 extends diagonally downward and rearward from the head pipe 11. The seat tube 16 extends upward from the rear end of the down tube 12. The chainstay 18 extends rearward from the lower end of the seat tube 16. The bracket 26 connects the rear end of the down tube 12, the lower end of the seat tube 16, and the front end of the chainstay 18. The top tube 14 is provided to connect the head pipe 11 and the upper part of the seat tube 16. A seatpost 17 is inserted into the seat tube 16, and a saddle 3 on which the user sits is provided at the upper end of the seatpost 17.

[0057] The rear end of the chainstay 18 rotatably supports the rear wheel 7, which is the drive wheel. The seatstay 19 extends diagonally downward and rearward from the top of the seat tube 16. The lower end of the seatstay 19 is connected to the rear end of the chainstay 18. A derailleur 28 for changing the gear ratio is provided at the rear end of the chainstay 18. The derailleur may be provided around the pedal crank axle 35. A speed sensor 29 for detecting the rotation of the rear wheel 7 is provided at the rear of the chainstay 18. The speed sensor 29 may be provided at the bottom of the front fork 15 to detect the rotation of the front wheel 6.

[0058] A drive unit 30 is mounted on a bracket 26 located near the center of the vehicle frame 2. The housing of the drive unit 30 contains an electric motor 32, an MCU (motor control unit), a reduction gear, etc. The pedal crank shaft 35 is supported by passing through the drive unit 30 in the left-right direction. Crank arms 36 are provided at both ends of the pedal crank shaft 35. A pedal 37 is rotatably mounted at the tip of the crank arm 36.

[0059] The electric assist bicycle 1 of this embodiment is equipped with multiple battery packs 21. In the example shown in Figure 1, battery packs 21a and 21b are mounted on the electric assist bicycle 1. For example, battery pack 21a is mounted on the down tube 12 and battery pack 21b is mounted on the top tube 14. In the example shown in Figure 1, battery pack 21a is mounted inside the down tube 12 and battery pack 21b is mounted inside the top tube 14. The down tube 12 and the top tube 14 may each have a hollow shape. The down tube 12 and the top tube 14 may each have a U-shaped cross-section in at least a part thereof and may have a cover that covers the U-shaped portion.

[0060] The battery pack 21a may be positioned on the outer surface of the down tube 12. The battery pack 21b may be positioned on the outer surface of the top tube 14. At least one of the battery packs 21a and 21b may be mounted on the bracket 26 or on the seat tube 16. The battery packs 21a and 21b may be detachable from the electric assist bicycle 1.

[0061] Each of the battery packs 21a and 21b has multiple battery cells and a BMS (Battery Management System). These multiple battery cells are rechargeable batteries that can be charged and discharged. The BMS controls the charging and discharging of the battery pack and monitors the status of the battery pack.

[0062] The electric assist bicycle 1 may be equipped with three or more battery packs 21.

[0063] The MCU of the drive unit 30 controls the operation of the electric motor 32 and the operation of each part of the electric assist bicycle 1. The MCU has a semiconductor integrated circuit such as a processor and a motor drive circuit. The rotation of the pedal crank shaft 35 generated by the user pressing the pedal 37 with their foot is transmitted to the rear wheel 7 via the drive sprocket 38 and chain 27. The MCU controls the electric motor 32 to generate a drive assist output corresponding to the rotation output of the pedal crank shaft 35 generated by the user pressing the pedal 37 with their foot. The assist force generated by the electric motor 32 is transmitted to the rear wheel 7 via the drive sprocket 38 and chain 27. A belt, shaft, etc. may be used instead of the chain 27.

[0064] Figure 2 is a block diagram showing an example of the hardware configuration of the battery pack 21. Each of the battery packs 21a and 21b comprises the components illustrated in Figure 2.

[0065] The battery pack 21 includes a BMS 120, a battery module 126, and a sensor 127. The BMS 120 controls various operations of the battery pack 21, such as charging and discharging, and monitors the status of the battery pack 21. The BMS 120 monitors the voltage, current, temperature, SOC (State of Charge), SOH (State of Health), etc. of the battery pack 21. The BMS 120 includes a processing unit 121, a ROM (Read Only Memory) 122, a RAM (Random Access Memory) 123, a communication device 124, and a cell monitor 125.

[0066] ROM 122 stores a computer program (or firmware) that causes the processing unit 121 to perform processing. The computer program may be stored in ROM 122 during the manufacturing of the battery pack 21. The computer program may be provided to the battery pack 21 via a storage medium or telecommunications line. Such a computer program may be sold as commercial software.

[0067] The processing unit 121 is a semiconductor integrated circuit such as a processor, and includes, for example, a central processing unit (CPU). The processing unit 121 can be implemented by a microprocessor or a microcontroller. The processing unit 121 sequentially executes a computer program (a computer program stored in the ROM 122) that describes a set of instructions for performing various processes, thereby realizing the desired process.

[0068] The processing unit 121 may be an FPGA (Field Programmable Gate Array) equipped with a CPU, a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), an ASSP (Application Specific Standard Product), or a combination of two or more circuits selected from these circuits.

[0069] ROM122 may be, for example, writable memory (e.g., PROM), rewritable memory (e.g., flash memory), or read-only memory. Again, ROM122 may store computer programs that cause the processing unit 121 to perform processing. Furthermore, ROM122 may store computer programs that control the operation of the processing unit 121. ROM122 does not have to be a single recording medium, but may be a collection of multiple recording media. Some of the collection of multiple recording media may be removable memory.

[0070] RAM123 provides a workspace for temporarily unpacking computer programs stored in ROM122 during boot-up. RAM123 does not need to be a single storage medium; it may be a collection of multiple storage mediums.

[0071] The number of battery modules 126 in the battery pack 21 is arbitrary, with one or more battery modules 126 provided in the battery pack 21. Each battery module 126 is equipped with multiple battery cells 126a. The number of battery cells 126a in each battery module 126 is arbitrary.

[0072] Sensor 127 includes a current sensor for detecting the current of the battery pack 21, a voltage sensor for detecting the voltage of the battery pack 21, and a temperature sensor for detecting the temperature of the battery pack 21. The cell monitor 125 monitors the current, voltage, temperature, etc. of the battery pack 21 based on the output signals of sensor 127. The cell monitor 125 outputs information indicating the current, voltage, temperature, etc. to the processing unit 121. Sensor 127 may also detect the current, voltage, temperature, etc. of each battery module 126.

[0073] The communication device 124 is a communication module for wired communication with the drive unit 30. The communication device 124 can also perform wired communication between multiple battery packs. Communication is performed using a communication method such as CAN (Controller Area Network). Communication is not limited to wired communication; it may also be wireless communication.

[0074] As described above, the battery pack 21 may be a portable battery that can be attached to and detached from the electric assist bicycle 1. Figure 3 shows how to attach and detach the battery pack 21a from the electric assist bicycle 1. In this example, the battery pack 21a is mounted inside the down tube 12. The down tube 12 has a U-shaped cross-section in at least a portion thereof and has a cover 12a that covers the U-shaped portion. By opening the cover 12a, the battery pack 21a can be removed from the down tube 12 or attached to the down tube 12.

[0075] Similar to attaching and detaching the battery pack 21a, the battery pack 21b can be removed from the top tube 14 or attached to the top tube 14 by opening the cover of the top tube 14.

[0076] Because the battery pack 21 is detachable, it can be removed from the electric assist bicycle 1 and charged by connecting it to an external charging device. This means that even if a charging device for the battery pack 21 is not provided at the parking location, the battery pack 21 can be charged by transporting it to a location where a charging device is available. Furthermore, because the battery pack 21 is detachable, the number of battery packs 21 installed on the electric assist bicycle 1 can be adjusted.

[0077] The battery pack 21 may be charged while it is attached to the electric assist bicycle 1. In this case, for example, the battery pack 21 can be charged by connecting the connector of the charging device to a connector provided on the electric assist bicycle.

[0078] Figure 4 is a block diagram showing an example of the hardware configuration of the drive unit 30.

[0079] The drive unit 30 includes an MCU 130, an electric motor 32, and a sensor 137. The MCU 130 includes a processing unit 131, a ROM 132, a RAM 133, a communication device 134, and a drive device 135. The description of the configuration of the processing unit 131, ROM 132, and RAM 133 is omitted here because it overlaps with the description of the processing unit 121, ROM 122, and RAM 123 of the battery pack 21.

[0080] ROM 132 stores a computer program (or firmware) that causes the processing unit 131 to perform processing. The computer program may be stored in ROM 132 during the manufacture of the drive unit 30. The computer program may be provided to the drive unit 30 via a storage medium or telecommunications line. Such a computer program may be sold as commercial software. The processing unit 131 sequentially executes the computer program (the computer program stored in ROM 132) which describes a set of instructions for performing various processes, thereby realizing the desired processing. The processing unit 131 controls the operation of the drive unit 30.

[0081] The drive unit 135 includes a power supply circuit that outputs power to drive the electric motor 32. The power supply circuit includes, for example, a smoothing circuit that smooths the DC voltage output from the battery pack 21, and an inverter circuit that generates the motor drive current.

[0082] The sensors 137 include a torque sensor that detects torque generated on the rotating shaft including the pedal crank shaft 35, and a rotation sensor that detects the rotation of the electric motor 32. The processing unit 131 controls the operation of the drive unit 135 based on the output signals of the sensors 137.

[0083] The processing unit 131 controls the drive unit 135 so that the electric motor 32 generates an auxiliary force corresponding to the magnitude of the torque detected by the torque sensor. The drive unit 135 generates and outputs a motor drive current to drive the electric motor 32. The electric motor 32, supplied with the motor drive current, rotates and generates an auxiliary force. The auxiliary force generated by the electric motor 32 is transmitted to the drive sprocket 38 (Figure 1) via a reduction gear or the like. The rotation of the drive sprocket 38 is transmitted to the rear wheel 7 via the chain 27.

[0084] The communication device 134 is a communication module for wired communication with the battery pack 21 and the meter unit 5 (Figure 1). Communication is performed using a communication method such as CAN. The communication device 134 may also communicate wirelessly with the battery pack 21 and / or the meter unit 5.

[0085] [Battery control system] Next, a battery control system that controls the operation of multiple battery packs 21 will be described.

[0086] Figure 5 is a block diagram of the battery control system 20 according to this embodiment. The battery control system 20 includes a plurality of battery packs 21. In the example shown in Figure 5, the battery control system 20 includes battery packs 21a and 21b as battery packs 21.

[0087] Each of the multiple battery packs 21 includes a battery housing 110 that houses a BMS 120 and a battery module 126. The battery housing 110 is also called a casing. The battery housing 110 is provided with a connector (plug) 111.

[0088] The electric assist bicycle 1 is provided with connectors (receptacles) 101 and 102 that connect to the connector 111 of the battery pack 21. Connectors 101 and 102 are provided, for example, inside the down tube 12 and the top tube 14. In the example shown in Figure 5, the connector 111 of battery pack 21a is connected to connector 101, and the connector 111 of battery pack 21b is connected to connector 102.

[0089] Battery pack 21a can supply power to the MCU 130 to drive the electric motor 32 and communicate with the MCU 130 via connectors 111 and 101. Battery pack 21b can supply power to the MCU 130 to drive the electric motor 32 and communicate with the MCU 130 via connectors 111 and 102. Battery packs 21a and 21b can communicate with each other via connectors 111, 101 and 102.

[0090] In this embodiment, one of the multiple battery packs 21 has the authority to output power to drive the electric motor 32, while the other battery packs 21 do not have this authority. The battery pack 21 with the authority supplies power to drive the electric motor 32 to the MCU 130, while the battery packs 21 without the authority remain in standby mode without supplying power to drive the electric motor 32 to the MCU 130.

[0091] In this embodiment, a battery pack that has the authority to output power to drive the electric motor 32 is referred to as an "authorized battery pack." A battery pack that does not have the authority to output power to drive the electric motor 32 is referred to as an "unauthorized battery pack."

[0092] In the initial setup when the power of the electric assist bicycle 1 is turned on, which battery pack 21 becomes the "authorized battery pack" may be determined, for example, based on the connection positions of multiple battery packs 21 to the electric assist bicycle 1, or it may be determined by sending and receiving information between multiple battery packs 21.

[0093] For example, the MCU 130 assigns different unique information to the battery pack 21 connected to connector 101 and the battery pack 21 connected to connector 102. The BMS 120 of the battery pack 21 can determine whether to set it as an "authorized battery pack" or an "unauthorized battery pack" based on the assigned unique information. The unique information may be pre-assigned to each of multiple battery packs 21. In addition, one of the connectors 101 and 102 may be provided with a terminal to specify that it should be a "authorized battery pack".

[0094] Here, as an example, we will set battery pack 21a connected to connector 101 as an "authorized battery pack" and battery pack 21b connected to connector 102 as an "unauthorized battery pack".

[0095] In this embodiment, information is transmitted and received between the BMS 120s of multiple battery packs 21. The processing unit 121 of battery pack 21a generates and outputs internal information regarding the state of battery pack 21a. The BMS 120 of battery pack 21b generates and outputs internal information regarding the state of battery pack 21b.

[0096] Internal information includes, for example, one or more of the following: survival information, information indicating the presence or absence of abnormalities, information indicating whether or not authorization is granted, information indicating the upper limit of the output current, information indicating the remaining battery capacity, and information indicating the battery capacity. Information indicating the remaining battery capacity includes, for example, SOC (State of Charge), DOD (Depth of Discharge), ampere-hours (Ah), and watt-hours (Wh). Information indicating the battery capacity includes, for example, FCC (Full Charge Capacity), SOH (State of Health), and discharge capacity (Ah, Wh). The BMS120 can generate this information by performing calculations based on, for example, the detected value of the sensor 127 and the counted time. Survival information is information for confirming whether the battery pack 21 is operating. The BMS120 may output, for example, a heartbeat as survival information.

[0097] The BMS120s of multiple battery packs 21 mutually transmit and receive internal information from each battery pack. This allows the multiple battery packs 21 to monitor the status of each other.

[0098] The type of information contained in the internal information transmitted and received between multiple battery packs 21 can be the same among them. This allows the multiple battery packs 21 to monitor each other's status without any master-slave relationship.

[0099] In this embodiment, the authorized battery pack 21 among the multiple battery packs 21 is changed based on the internal information described above.

[0100] Figure 6 is a flowchart illustrating an example of the process for changing the authorized battery pack 21. The BMS 120s of battery packs 21a and 21b mutually transmit and receive internal information of their respective battery packs (step S101) and monitor the status of each of the multiple battery packs (step S102). At this time, the processing unit 121 of battery pack 21a monitors the status of battery pack 21a, and the processing unit 121 of battery pack 21b monitors the status of battery pack 21b.

[0101] The processing unit 121 of the battery pack 21a, which is the "authorized battery pack," controls the output of power to the MCU 130 to drive the electric motor 32. The state of the battery pack 21a changes during the process of outputting power to the MCU 130. For example, the upper limit of the current that the battery pack 21a can output changes due to a decrease in battery capacity and an increase in battery temperature. For example, the ROM 122 of the BMS 120 has table information pre-stored that shows the relationship between battery capacity, battery temperature, and the upper limit of the output current. The processing unit 121 changes the upper limit of the output current based on such table information.

[0102] The processing unit 121 of the battery pack 21a determines whether the battery pack 21a is in a predetermined state (step S103). The predetermined state is, for example, at least one of the following states: the upper limit of the output current is below a threshold, the output voltage is below a threshold, the remaining battery capacity is below a threshold, or the battery temperature is above a threshold. Information on each of these thresholds is stored in advance in the ROM 122 of the BMS 120.

[0103] When the processing unit 121 of battery pack 21a determines that battery pack 21a is in a predetermined state, it outputs a command to battery pack 21b indicating that it will transfer authority to battery pack 21b (step S104). For example, when the upper limit of the current that battery pack 21a can output falls below a threshold, the processing unit 121 outputs the above command to battery pack 21b. When the processing unit 121 of battery pack 21b receives the above command, it updates battery pack 21b to an "authorized battery pack" (step S105). For example, the processing unit 121 of battery pack 21b updates the information indicating whether or not it has authority to "authorized" and stores it in ROM 122.

[0104] The processing unit 121 of the battery pack 21a updates the battery pack 21a to an "unauthorized battery pack". For example, the processing unit 121 of the battery pack 21a updates the information indicating whether or not it is authorized to "unauthorized" and stores it in the ROM 122. The processing unit 121 of the battery pack 21a that has been updated to an "unauthorized battery pack" stops the control that outputs power to the MCU 130 to drive the electric motor 32, but continues to send and receive internal information between multiple battery packs 21. The continuation of sending and receiving internal information of the battery pack 21a can be done, for example, using a predischarge output.

[0105] The processing unit 121 of the battery pack 21b, which has been newly designated as an "authorized battery pack," controls the output of power to the MCU 130 to drive the electric motor 32.

[0106] According to this embodiment, when the battery pack 21a is in a predetermined state (for example, when the upper limit of the output current is below a threshold), the authority is transferred from battery pack 21a to battery pack 21b. This ensures a stable power supply to the drive unit 30.

[0107] The authorized battery pack is changed by mutually sending and receiving information between the BMS 120s of multiple battery packs 21. The MCU 130 of the drive unit 30 does not need to monitor the status of multiple battery packs 21 and perform the process of changing the authorized battery pack 21. This reduces the communication load and computation load on the MCU 130.

[0108] Figure 7 is a flowchart illustrating another example of the process for changing the authorized battery pack 21. The authorized battery pack 21 may be changed when the existence of the currently authorized battery pack 21 can no longer be confirmed due to a failure of the currently authorized battery pack 21, etc.

[0109] The operations of steps S201 and S202 shown in Figure 7 are the same as the operations of steps S101 and S102 shown in Figure 6. The BMS120s of the multiple battery packs 21 send and receive survival information to and from each other. Bidirectional communication of survival information occurs multiple times per second.

[0110] The processing unit 121 of battery pack 21a, which is the "authorized battery pack," transmits survival information to battery pack 21b. The processing unit 121 of battery pack 21b determines whether or not it has received survival information from battery pack 21a (step S203).

[0111] If the processing unit 121 of battery pack 21b determines that it cannot receive survival information from battery pack 21a, it updates battery pack 21b to an "authorized battery pack" (step S204). For example, if the processing unit 121 of battery pack 21b cannot continuously receive survival information from battery pack 21a for a predetermined period of time, it updates battery pack 21b to an "authorized battery pack". The predetermined period is, for example, 3 to 6 seconds, but is not limited to that value.

[0112] The processing unit 121 of the battery pack 21b, which has been newly designated as an "authorized battery pack," controls the output of power to the MCU 130 to drive the electric motor 32.

[0113] If the operation of the authorized battery pack 21a cannot be confirmed, battery pack 21b is set to the authorized battery pack. This ensures a stable power supply to the drive unit 30.

[0114] The process of changing the authorized battery pack 21 can also be applied to configurations in which three or more battery packs 21 are mounted on the electric assist bicycle 1.

[0115] Figure 8 is a block diagram showing another example of the battery control system 20 according to this embodiment. In the example shown in Figure 8, the battery control system 20 includes three battery packs 21a, 21b, and 21c as the battery pack 21. Battery pack 21c has the same configuration as, for example, battery packs 21a and 21b. The placement of battery pack 21c is arbitrary. Battery pack 21c is mounted, for example, on the down tube 12, top tube 14, or seat tube 16.

[0116] In the example shown in Figure 8, the electric assist bicycle 1 is equipped with a connector (receptacle) 103. The connector 111 of the battery pack 21c is connected to the connector 103.

[0117] Battery pack 21c can supply power to the MCU 130 to drive the electric motor 32 via connectors 111 and 103, and can also communicate with the MCU 130. Battery packs 21a, 21b, and 21c can communicate with each other via connectors 111, 101, 102, and 103.

[0118] Here, as an example, we will set battery pack 21a connected to connector 101 as an "authorized battery pack," and battery packs 21b and 21c connected to connectors 102 and 103 as "unauthorized battery packs."

[0119] Figure 9 is a flowchart showing yet another example of the process of changing the authorized battery pack 21. The operations of steps S101 to S103 shown in Figure 9 are the same as the operations of steps S101 to S103 shown in Figure 6, except for the number of battery packs 21. The BMS 120s of battery packs 21a, 21b, and 21c send and receive internal information of each battery pack to each other (step S101) and monitor the status of each of the multiple battery packs to each other (step S102).

[0120] The processing unit 121 of the battery pack 21a, which is an "authorized battery pack," determines whether the battery pack 21a is in a predetermined state (step S103). The predetermined state is, for example, at least one of the following states: the upper limit of the outputtable current is less than a threshold, the output voltage is less than a threshold, the remaining battery capacity is less than a threshold, or the battery temperature is above a threshold.

[0121] When the battery pack 21a's processing unit 121 determines that the battery pack 21a is in a predetermined state, it determines which battery pack to transfer authority to from among the battery packs 21b and 21c that do not have authority (step S111). For example, when the upper limit of the current that battery pack 21a can output falls below a threshold, the processing unit 121 determines which battery pack to transfer authority to.

[0122] The processing unit 121 of battery pack 21a determines which battery pack to transfer to from among battery packs 21b and 21c based on the internal information of each battery pack. For example, the processing unit 121 of battery pack 21a determines the battery pack with the largest remaining battery capacity among battery packs 21b and 21c as the transfer destination. Alternatively, for example, the processing unit 121 of battery pack 21a determines the battery pack with the largest upper limit of the output current among battery packs 21b and 21c as the transfer destination. This allows the authority to be transferred to a battery pack capable of supplying more power to the electric motor 32.

[0123] Furthermore, for example, the processing unit 121 of battery pack 21a may determine the recipient battery pack from among battery packs 21b and 21c based on the unique information assigned to each of them. For example, each of the connectors 101, 102, and 103 (Figure 8) may be provided with a terminal to specify the content of the unique information (e.g., a number). In this case, for example, the battery pack with the smallest number indicated by the unique information among battery packs 21b and 21c is determined to be the recipient battery pack. This allows the recipient battery pack to be determined with a simple process.

[0124] Here, as an example, let's assume that battery pack 21b is designated as the recipient battery pack. The processing unit 121 of battery pack 21a outputs a command to battery pack 21b indicating that it is transferring authority to battery pack 21b (step S104). Upon receiving the above command, the processing unit 121 of battery pack 21b updates battery pack 21b to a “authorized battery pack” (step S105). The processing unit 121 of battery pack 21a updates battery pack 21a to a “non-authorized battery pack”.

[0125] The processing unit 121 of the battery pack 21b, which has been newly designated as an "authorized battery pack," controls the output of power to the MCU 130 to drive the electric motor 32.

[0126] Figure 10 is a flowchart showing yet another example of the process of changing the authorized battery pack 21.

[0127] The operation of steps S201 to S203 shown in Figure 10 is the same as the operation of steps S201 to S203 shown in Figure 7, except for the number of battery packs 21. The BMS 120s of the multiple battery packs 21 send and receive survival information to and from each other.

[0128] The processing unit 121 of battery pack 21a, which is the "authorized battery pack," transmits survival information to battery packs 21b and 21c. The processing units 121 of battery packs 21b and 21c determine whether or not they have received survival information from battery pack 21a (step S203).

[0129] If the battery packs 21b and 21c processing unit 121 determines that it cannot receive survival information from battery pack 21a, it determines which battery pack from battery packs 21b and 21c will be authorized (step S211). Based on the internal information of each battery pack 21b and 21c, the battery packs 21b and 21c processing unit 121 determines which battery pack from battery packs 21b and 21c will be authorized. For example, the battery packs 21b and 21c processing unit 121 may determine which battery pack from battery packs 21b and 21c has the largest remaining battery capacity as the battery pack to be authorized. Alternatively, for example, the battery packs 21b and 21c processing unit 121 may determine which battery pack from battery packs 21b and 21c has the largest upper limit of the output current as the battery pack to be authorized. Furthermore, for example, the processing units 121 for battery packs 21b and 21c may determine which battery pack to grant authorization to from among battery packs 21b and 21c based on the unique information assigned to each of them.

[0130] Here, as an example, let's assume that battery pack 21c is determined to be the battery pack to be granted authority. In this case, the processing unit 121 of battery pack 21c updates battery pack 21c to an "authorized battery pack" (step S204). The processing unit 121 of battery pack 21b maintains that battery pack 21b is an "unauthorized battery pack".

[0131] The processing unit 121 of the battery pack 21c, which has been newly designated as an "authorized battery pack," controls the output of power to the MCU 130 to drive the electric motor 32.

[0132] In the example above, the processing units 121 of battery packs 21b and 21c determined which battery pack to grant authority to, but the processing unit 121 of either battery pack 21b or 21c may determine which battery pack to grant authority to.

[0133] In the embodiment described above, power to drive the electric motor 32 was supplied to the MCU 130 from an authorized battery pack 21, but the present invention is not limited thereto. The authorized battery pack 21 may also control the supply of power to the MCU 130 from an unauthorized battery pack 21.

[0134] The process of changing the authorized battery pack 21 based on its status, as explained using Figures 7 and 10, can also be applied to the charging of multiple battery packs 21. In this case, the authorized battery pack 21 controls the charging of multiple battery packs 21. As shown in Figures 7 and 10, if status information for the authorized battery pack 21 cannot be received, the authorized battery pack is changed to another battery pack 21. This allows for control of the charging of the normal battery packs 21.

[0135] In the embodiments described above, the drive wheel to which the human power generated by the user pedaling and the assistive power generated by the electric motor were transmitted was the rear wheel, but the present invention is not limited to this. Depending on the form of the electric assist bicycle, the human power and assistive power may be transmitted to the front wheel, or to both the front and rear wheels. Furthermore, the present invention may be applied to an electric assist bicycle equipped with a hub motor on the front wheel.

[0136] The above describes exemplary embodiments of the present invention. This specification discloses a battery control system, battery pack, small electric vehicle, battery control method, and computer program as described in the following sections.

[0137] [Item 1] A battery control system 20 for a small electric vehicle 1, Equipped with multiple battery packs 21, Each of the multiple battery packs 21 is A battery module 126 having multiple battery cells 126a, A control device 120 that controls the discharge of the battery module 126, the control device 120 which outputs internal information regarding the state of the battery pack 21 located inside the control device 120, A battery housing 110 that houses the battery module 126 and the control device 120 inside, Equipped with, The multiple battery packs 21 include battery packs 21 that have the authority to output power to drive the electric motor 32 that generates the driving force to move the small electric vehicle 1, and battery packs 21 that do not have that authority. Multiple control devices 120 of multiple battery packs 21 transmit and receive internal information to each other. A battery control system 20 in which at least one of the multiple control devices 120 changes the authorized battery pack 21 among the multiple battery packs 21 based on internal information.

[0138] According to one embodiment of the present invention, internal information is transmitted and received between multiple battery packs 21, and the authorized battery pack 21 is changed based on the internal information. The vehicle control device 130, which controls the driving of the vehicle, no longer needs to monitor the status of the multiple battery packs 21 and perform the process of changing the authorized battery pack 21, thereby reducing the communication load and computation load of the vehicle control device 130.

[0139] [Item 2] Internal information is, Survival information to check if battery pack 21 is working, Information indicating the presence or absence of abnormalities, Information indicating whether or not permission is granted. Information indicating the upper limit of the output current, Information indicating remaining battery capacity, Information indicating battery capacity, A battery control system 20 as described in item 1, including one or more of the following:

[0140] This allows multiple battery packs 21 to monitor each other's status.

[0141] [Item 3] Multiple battery packs 21 include a first battery pack 21a which is an authorized battery pack, and a second battery pack 21b which is an unauthorized battery pack. When the control device 120 of the first battery pack 21a determines that the first battery pack 21a is in a predetermined state, it outputs a command to the second battery pack 21b indicating that it will transfer authority to the second battery pack 21b. The control device 120 of the second battery pack 21b sets the second battery pack 21b to an authorized battery pack, as described in item 1 or 2 of the battery control system 20.

[0142] When the first battery pack 21a is in a predetermined state (for example, when the upper limit of the output current is below a threshold), the above authority is transferred from the first battery pack 21a to the second battery pack 21b. This ensures a stable power supply to the vehicle.

[0143] [Item 4] The specified state is, A state in which the upper limit of the output current is below the threshold, The state in which the output voltage is below the threshold, When the remaining battery capacity is below a threshold, A state in which the temperature is above a threshold, A battery control system 20 as described in item 3, which is at least one of the following.

[0144] If the first battery pack 21a is in the above state, the vehicle can continue to receive a stable power supply by transferring the above authority from the first battery pack 21a to the second battery pack 21b.

[0145] [Item 5] Multiple battery packs 21 include an authorized battery pack 21a and two or more non-authorized battery packs 21b and 21c. The control device 120 of the authorized battery pack 21a, If the authorized battery pack 21a is determined to be in a predetermined state, From among battery packs 21b and 21c that do not possess more than one set of authority, the recipient battery pack 21 to which the authority will be transferred is determined. A command indicating the transfer of authority to the recipient battery pack 21 is output to the recipient battery pack 21. The battery control system 20 described in item 1 or 2 sets the recipient battery pack 21 as an authorized battery pack, with the control device 120 of the recipient battery pack 21 being configured as such.

[0146] If the authorized battery pack 21a is in a predetermined state (for example, a state where the upper limit of the output current is below a threshold), it transfers the above authority to another battery pack 21. This ensures a stable power supply to the vehicle.

[0147] [Item 6] The specified state is, A state in which the upper limit of the output current is below the threshold, The state in which the output voltage is below the threshold, When the remaining battery capacity is below a threshold, A state in which the temperature is above a threshold, A battery control system 20 as described in item 5, which is at least one of the following.

[0148] If the battery pack 21a having the above authority is in the above state, the stable power supply to the vehicle can be continued by transferring the above authority to another battery pack 21.

[0149] [Item 7] The control device 120 of the battery pack 21a, which has authority prior to the transfer of authority, A battery control system 20 as described in item 5 or 6, which determines which battery pack to transfer from among the battery packs 21b and 21c that do not have two or more authorizations, based on the internal information of each of the battery packs 21b and 21c that do not have two or more authorizations.

[0150] This allows the above authority to be transferred to the appropriate battery pack 21.

[0151] [Item 8] The control device 120 of the battery pack 21a, which has authority prior to the transfer of authority, The battery control system 20 described in item 7 determines, among battery packs 21b and 21c that do not have authority over more than one, the battery pack with the largest remaining battery capacity or the battery pack with the largest maximum output current value as the battery pack to be transferred.

[0152] This allows the above authority to be transferred to the battery pack 21, which is capable of supplying greater power to the electric motor 32.

[0153] [Item 9] The control device 120 of the battery pack 21a, which has authority prior to the transfer of authority, A battery control system 20 as described in item 5 or 6, which determines the recipient battery pack from among the battery packs 21b and 21c that do not have two or more authorizations, based on unique information assigned to each of the battery packs 21b and 21c that do not have two or more authorizations.

[0154] This allows the recipient battery pack 21 to be determined through a simple process.

[0155] [Item 10] Internal information includes survival information, Multiple battery packs 21 include a first battery pack 21a which is an authorized battery pack, and a second battery pack 21b which is an unauthorized battery pack. The battery control system 20 described in item 2, wherein the control device 120 of the second battery pack 21b sets the second battery pack 21b as the authorized battery pack if it cannot receive survival information from the first battery pack 21a.

[0156] If the first battery pack 21a, which has the above authority, is not operating, the second battery pack 21b is set to be the battery pack with the above authority. This ensures a stable power supply to the vehicle.

[0157] [Item 11] Internal information includes survival information, Multiple battery packs 21 include an authorized battery pack 21a and two or more non-authorized battery packs 21b and 21c. At least one of the control devices 120 of battery packs 21b and 21c that does not have more than one authority, If survival information cannot be received from the authorized battery pack 21a, From among battery packs 21b and 21c that do not possess two or more authorizations, determine which battery pack to grant authorization to. The battery control system 20 described in item 2 sets the target battery pack as an authorized battery pack, with the control device 120 of the target battery pack being the control device 120 of the target battery pack.

[0158] If the battery pack 21a with the above authority is not operating, another battery pack 21b or 21c is set to be the battery pack with the above authority. This ensures a stable power supply to the vehicle.

[0159] [Item 12] At least one of the control devices 120 of battery packs 21b and 21c that does not have more than one authority, The battery control system 20 described in item 11 determines the target battery pack from among the battery packs 21b and 21c that do not have two or more authorizations, based on the internal information of each of the battery packs 21b and 21c that do not have two or more authorizations.

[0160] This allows the appropriate battery pack 21 to be granted the above permissions.

[0161] [Item 13] At least one of the control devices 120 of battery packs 21b and 21c that does not have more than one authority, The battery control system 20 described in item 12 determines the target battery pack from among battery packs 21b and 21c that do not possess more than one authority, whichever battery pack has the largest remaining battery capacity or the largest maximum output current.

[0162] This allows the battery pack 21 to be granted the above authority, which enables it to supply greater power to the electric motor 32.

[0163] [Item 14] At least one of the control devices 120 of battery packs 21b and 21c that does not have more than one authority, The battery control system 20 described in item 11 determines the target battery pack from among the battery packs 21b and 21c that do not have two or more authorizations, based on the unique information assigned to each of the battery packs 21b and 21c that do not have two or more authorizations.

[0164] This makes it possible to determine which battery pack 21 to grant the above permissions to with a simple process.

[0165] [Item 15] The battery control system 20 according to any one of items 1 to 14, wherein the type of information contained in the internal information transmitted and received between multiple battery packs 21 is the same among the multiple battery packs 21.

[0166] This allows multiple battery packs 21 to monitor each other's status without any master-slave relationship.

[0167] [Item 16] A battery control system 20 according to any one of items 1 to 15, wherein multiple battery packs 21 are detachable from a small electric vehicle 1.

[0168] This allows the battery pack 21 to be charged while it is removed from the vehicle. Furthermore, the number of battery packs 21 installed in the vehicle can be adjusted.

[0169] [Item 17] A small electric vehicle 1, equipped with a battery control system 20 as described in any of items 1 to 16.

[0170] This makes it possible to realize a compact electric vehicle 1 with reduced communication and computational load on the vehicle control device 130.

[0171] [Item 18] Small electric vehicle 1 is an electric assist bicycle, as described in item 17.

[0172] This makes it possible to realize an electric assist bicycle with reduced communication and computational load on the vehicle control unit (MCU) 130.

[0173] [Item 19] A battery control method for controlling multiple battery packs 21 for a small electric vehicle 1, which is executed by multiple computers, The multiple battery packs 21 include battery packs 21 that have the authority to output power to drive the electric motor 32 that generates the driving force to move the small electric vehicle 1, and battery packs 21 that do not have that authority. Each of the multiple battery packs 21 outputs internal information about the state of its own battery pack 21. The battery control method is, Intermittent transmission and reception of internal information between multiple battery packs 21, Based on internal information exchanged between multiple battery packs 21, the authorized battery pack 21 among the multiple battery packs 21 is changed. A battery control method, including...

[0174] According to one embodiment of the present invention, internal information is transmitted and received between multiple battery packs 21, and the authorized battery pack 21 is changed based on the internal information. The vehicle control device 130, which controls the driving of the vehicle, no longer needs to monitor the status of the multiple battery packs 21 and perform the process of changing the authorized battery pack 21, thereby reducing the communication load and computation load of the vehicle control device 130.

[0175] [Item 20] A computer program that causes multiple computers to perform control processing for multiple battery packs 21 for a small electric vehicle 1, The multiple battery packs 21 include battery packs 21 that have the authority to output power to drive the electric motor 32 that generates the driving force to move the small electric vehicle 1, and battery packs 21 that do not have that authority. Each of the multiple battery packs 21 outputs internal information about the state of its own battery pack 21. Computer programs are Intermittent transmission and reception of internal information between multiple battery packs 21, Based on internal information exchanged between multiple battery packs 21, the authorized battery pack 21 among the multiple battery packs 21 is changed. A computer program that causes multiple computers to run the same program.

[0176] According to one embodiment of the present invention, internal information is transmitted and received between multiple battery packs 21, and the authorized battery pack 21 is changed based on the internal information. The vehicle control device 130, which controls the driving of the vehicle, no longer needs to monitor the status of the multiple battery packs 21 and perform the process of changing the authorized battery pack 21, thereby reducing the communication load and computation load of the vehicle control device 130.

[0177] [Item 21] A battery pack 21 for a small electric vehicle 1, A battery module 126 having multiple battery cells 126a, A control device 120 that controls the discharge of the battery module 126, A battery housing 110 that houses the battery module 126 and the control device 120 inside, Equipped with, The small electric vehicle 1 is equipped with multiple battery packs 21. Each of the multiple battery packs 21 outputs internal information about the state of its own battery pack 21. The multiple battery packs 21 include battery packs 21 that have the authority to output power to drive the electric motor 32 that generates the driving force to move the small electric vehicle 1, and battery packs 21 that do not have that authority. Multiple battery packs 21 send and receive internal information to each other. The control device 120 changes the authorized battery pack 21 from among the multiple battery packs 21 based on internal information transmitted and received between the multiple battery packs 21.

[0178] According to one embodiment of the present invention, internal information is transmitted and received between multiple battery packs 21, and the authorized battery pack 21 is changed based on the internal information. The vehicle control device 130, which controls the driving of the vehicle, no longer needs to monitor the status of the multiple battery packs 21 and perform the process of changing the authorized battery pack 21, thereby reducing the communication load and computation load of the vehicle control device 130. [Industrial applicability]

[0179] This invention is particularly useful in the field of small electric vehicles. [Explanation of symbols]

[0180] 1: Small electric vehicle (electric assist bicycle), 2: Frame, 3: Saddle, 4: Handlebars, 5: Meter unit, 6: Front wheel, 7: Rear wheel, 8: Headlamp, 11: Head pipe, 12: Down tube, 12a: Cover, 13: Handlebar column, 14: Top tube, 15: Front fork, 16: Seat tube, 17: Seat post, 18: Chainstay, 19: Seatstay, 20: Battery control system, 21: Battery pack, 26: Bracket, 27: Chain, 28: Gear shifter, 29: Speed ​​sensor, 30: Drive unit, 32: Electric motor, 35: Pedal crank axle, 36: Crank arm, 37: Pedal, 38: Drive sprocket, 101: Connector, 102: Connector, 103: Connector, 110: Battery housing, 111: Connector, 120: BMS, 121: Processing Unit, 122: ROM, 123: RAM, 124: Communication Device, 125: Cell Monitor, 126: Battery Module, 126a: Battery Cell, 127: Sensor, 130: MCU, 131: Processing Unit, 132: ROM, 133: RAM, 134: Communication Device, 135: Drive Unit, 137: Sensor

Claims

1. A battery control system for an electric vehicle, Equipped with multiple battery packs, Each of the aforementioned plurality of battery packs is A battery module having multiple battery cells, A control device for controlling the discharge of the battery module, the control device having an internal control device that outputs internal information relating to the state of the battery pack, A battery housing that houses the battery module and the control device inside, Equipped with, The plurality of battery packs include battery packs that have the authority to output power to drive an electric motor that generates the driving force to move the electric vehicle, and battery packs that do not have the authority. The multiple control devices of the multiple battery packs transmit and receive the internal information to each other. At least one of the multiple control devices modifies the authorized battery pack among the multiple battery packs based on the internal information, The plurality of battery packs include a first battery pack which is the authorized battery pack and a second battery pack which is the unauthorized battery pack, When the control device of the first battery pack determines that the first battery pack is in a predetermined state, it outputs a command to the second battery pack indicating that it will transfer the authority to the second battery pack. The control device of the second battery pack is a battery control system that sets the second battery pack to the authorized battery pack.

2. The aforementioned internal information is, Survival information to confirm whether the aforementioned battery pack is operating, Information indicating the presence or absence of abnormalities, Information indicating whether or not the aforementioned authority exists, Information indicating the upper limit of the output current, Information indicating remaining battery capacity, Information indicating battery capacity, The battery control system according to claim 1, comprising one or more of the following:

3. The aforementioned predetermined state is, A state in which the upper limit of the output current is below the threshold, The state in which the output voltage is below the threshold, When the remaining battery capacity is below a threshold, A state in which the temperature is above a threshold, The battery control system according to claim 1, wherein at least one of the following is included.

4. A battery control system for an electric vehicle, Equipped with multiple battery packs, Each of the aforementioned plurality of battery packs is A battery module having multiple battery cells, A control device for controlling the discharge of the battery module, the control device having an internal control device that outputs internal information relating to the state of the battery pack, A battery housing that houses the battery module and the control device inside, Equipped with, The plurality of battery packs include battery packs that have the authority to output power to drive an electric motor that generates the driving force to move the electric vehicle, and battery packs that do not have the authority. The multiple control devices of the multiple battery packs transmit and receive the internal information to each other. At least one of the multiple control devices modifies the authorized battery pack among the multiple battery packs based on the internal information, The plurality of battery packs include the authorized battery pack and two or more battery packs that do not have the authorized, The control device of the battery pack having the aforementioned authority If the battery pack having the aforementioned authority is determined to be in a predetermined state, From among two or more battery packs that do not possess the aforementioned authority, determine which battery pack will be to which the authority will be transferred. A command indicating the transfer of the authority to the transferee battery pack is output to the transferee battery pack, The control device of the transferee battery pack is a battery control system that sets the transferee battery pack as the authorized battery pack.

5. The aforementioned predetermined state is, A state in which the upper limit of the output current is below the threshold, The state in which the output voltage is below the threshold, When the remaining battery capacity is below a threshold, A state in which the temperature is above a threshold, The battery control system according to claim 4, wherein at least one of the following is included.

6. Prior to the transfer of the said authority, the control device of the battery pack having said authority is: The battery control system according to claim 4, which determines the transfer recipient battery pack from among the two or more battery packs that do not have the authority, based on the internal information of each of the two or more battery packs that do not have the authority.

7. Prior to the transfer of the said authority, the control device of the battery pack having said authority is: The battery control system according to claim 6, which determines the battery pack to be transferred from among two or more battery packs that do not have the aforementioned authority, the battery pack with the largest remaining battery capacity or the battery pack with the largest upper limit of the output current.

8. Prior to the transfer of the said authority, the control device of the battery pack having said authority is: The battery control system according to claim 4, which determines the transfer recipient battery pack from among the two or more battery packs that do not have the aforementioned authority, based on unique information assigned to each of the two or more battery packs that do not have the aforementioned authority.

9. A battery control system for an electric vehicle, Equipped with multiple battery packs, Each of the aforementioned plurality of battery packs is A battery module having multiple battery cells, A control device for controlling the discharge of the battery module, the control device having an internal control device that outputs internal information relating to the state of the battery pack, A battery housing that houses the battery module and the control device inside, Equipped with, The plurality of battery packs include battery packs that have the authority to output power to drive an electric motor that generates the driving force to move the electric vehicle, and battery packs that do not have the authority. The multiple control devices of the multiple battery packs transmit and receive the internal information to each other. At least one of the multiple control devices modifies the authorized battery pack among the multiple battery packs based on the internal information, The aforementioned internal information is, Survival information to confirm whether the aforementioned battery pack is operating, Information indicating the presence or absence of abnormalities, Information indicating whether or not the aforementioned authority exists, Information indicating the upper limit of the output current, Information indicating remaining battery capacity, Information indicating battery capacity, Includes one or more of the following: The aforementioned internal information includes the survival information, The plurality of battery packs include a first battery pack which is the authorized battery pack and a second battery pack which is the unauthorized battery pack, A battery control system in which the control device of the second battery pack, if it cannot receive the survival information from the first battery pack, sets the second battery pack to the authorized battery pack.

10. A battery control system for an electric vehicle, Equipped with multiple battery packs, Each of the aforementioned plurality of battery packs is A battery module having multiple battery cells, A control device for controlling the discharge of the battery module, the control device having an internal control device that outputs internal information relating to the state of the battery pack, A battery housing that houses the battery module and the control device inside, Equipped with, The plurality of battery packs include battery packs that have the authority to output power to drive an electric motor that generates the driving force to move the electric vehicle, and battery packs that do not have the authority. The multiple control devices of the multiple battery packs transmit and receive the internal information to each other. At least one of the multiple control devices modifies the authorized battery pack among the multiple battery packs based on the internal information, The aforementioned internal information is, Survival information to confirm whether the aforementioned battery pack is operating, Information indicating the presence or absence of abnormalities, Information indicating whether or not the aforementioned authority exists, Information indicating the upper limit of the output current, Information indicating remaining battery capacity, Information indicating battery capacity, Includes one or more of the following: The aforementioned internal information includes the survival information, The plurality of battery packs include the authorized battery pack and two or more battery packs that do not have the authorized, At least one of the control devices of two or more battery packs that do not have the aforementioned authority, If the survival information cannot be received from the battery pack having the aforementioned authority, From among two or more battery packs that do not possess the aforementioned authority, determine which battery pack is to be granted the aforementioned authority. The control device of the target battery pack is a battery control system that sets the target battery pack to the authorized battery pack.

11. At least one of the control devices of two or more battery packs that do not have the aforementioned authority, The battery control system according to claim 10, which determines the target battery pack from among the two or more battery packs that do not have the necessary authority, based on the internal information of each of the two or more battery packs that do not have the necessary authority.

12. At least one of the control devices of two or more battery packs that do not have the aforementioned authority, The battery control system according to claim 11, which determines the target battery pack to be the battery pack with the largest remaining battery capacity or the battery pack with the largest upper limit of the output current among two or more battery packs that do not have the aforementioned authority.

13. At least one of the control devices of two or more battery packs that do not have the aforementioned authority, The battery control system according to claim 10, which determines the target battery pack from among the two or more battery packs that do not have the necessary authority, based on unique information assigned to each of the two or more battery packs that do not have the necessary authority.

14. The battery control system according to claim 1 or 2, wherein the type of information contained in the internal information transmitted and received between the plurality of battery packs is the same among the plurality of battery packs.

15. A battery control system for an electric vehicle, Equipped with multiple battery packs, Each of the aforementioned plurality of battery packs is A battery module having multiple battery cells, A control device for controlling the discharge of the battery module, the control device having an internal control device that outputs internal information relating to the state of the battery pack, A battery housing that houses the battery module and the control device inside, Equipped with, The plurality of battery packs include battery packs that have the authority to output power to drive an electric motor that generates the driving force to move the electric vehicle, and battery packs that do not have the authority. The multiple control devices of the multiple battery packs transmit and receive the internal information to each other. At least one of the multiple control devices modifies the authorized battery pack among the multiple battery packs based on the internal information, The plurality of battery packs are a battery control system that can be attached to and detached from the electric vehicle.

16. An electric vehicle comprising the battery control system according to claim 1 or 2.

17. The electric vehicle according to claim 16, wherein the electric vehicle is an electric assist bicycle.

18. A battery control method for controlling multiple battery packs for an electric vehicle, which is run by multiple computers, The plurality of battery packs include battery packs that have the authority to output power to drive an electric motor that generates the driving force to move the electric vehicle, and battery packs that do not have the authority. Each of the aforementioned battery packs outputs internal information regarding the state of its own battery pack. The aforementioned battery control method is The internal information is transmitted and received between the plurality of battery packs. Based on the internal information transmitted and received between the plurality of battery packs, the battery pack with the authority among the plurality of battery packs is changed. Includes, The plurality of battery packs include a first battery pack which is the authorized battery pack and a second battery pack which is the unauthorized battery pack, The aforementioned battery control method is When it is determined that the first battery pack is in a predetermined state, the first battery pack outputs a command to the second battery pack indicating that it is transferring the authority to the second battery pack. To set the second battery pack to the battery pack having the authority, A battery control method, including...

19. A computer program that causes multiple computers to perform a process for controlling multiple battery packs for an electric vehicle, The plurality of battery packs include battery packs that have the authority to output power to drive an electric motor that generates the driving force to move the electric vehicle, and battery packs that do not have the authority. Each of the aforementioned battery packs outputs internal information regarding the state of its own battery pack. The aforementioned computer program, The internal information is transmitted and received between the plurality of battery packs. Based on the internal information transmitted and received between the plurality of battery packs, the battery pack with the authority among the plurality of battery packs is changed. The above-mentioned multiple computers are made to execute this, The plurality of battery packs include a first battery pack which is the authorized battery pack and a second battery pack which is the unauthorized battery pack, The aforementioned computer program, When it is determined that the first battery pack is in a predetermined state, the first battery pack outputs a command to the second battery pack indicating that it is transferring the authority to the second battery pack. To set the second battery pack to the battery pack having the authority, A computer program that causes the aforementioned multiple computers to execute it.

20. A battery pack for an electric vehicle, A battery module having multiple battery cells, A control device for controlling the discharge of the battery module, A battery housing that houses the battery module and the control device inside, Equipped with, The electric vehicle is equipped with multiple battery packs, including the aforementioned battery pack. Each of the plurality of battery packs comprises the battery module, the control device, and the battery housing. Each of the aforementioned battery packs outputs internal information regarding the state of its own battery pack. The plurality of battery packs include battery packs that have the authority to output power to drive an electric motor that generates the driving force to move the electric vehicle, and battery packs that do not have the authority. The aforementioned multiple battery packs mutually transmit and receive the internal information, The control device changes the authorized battery pack among the plurality of battery packs based on the internal information transmitted and received between the plurality of battery packs, The plurality of battery packs include a first battery pack which is the authorized battery pack and a second battery pack which is the unauthorized battery pack, When the control device of the first battery pack determines that the first battery pack is in a predetermined state, it outputs a command to the second battery pack indicating that it will transfer the authority to the second battery pack. The control device of the second battery pack sets the second battery pack to the authorized battery pack.

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