Electric vehicle and Anti-theft system for secondary battery

Abstract

Provided are an electric vehicle and a system that easily recognize the theft of a secondary battery of an electric vehicle represented by an electric assist bicycle to prevent theft. In order to prevent theft of a secondary battery that can be removed from an electric vehicle represented by an electric assist bicycle or an electric motorcycle, an electric vehicle body unit and a secondary battery unit mutually authenticate on a one-to-one basis. At least the secondary battery unit is configured to include a first storage unit for storing first identification information, an authentication unit, and a wireless communication unit.

Description

Anti-theft system for electric vehicles and secondary batteries

[0001] This invention relates to an electric vehicle and its anti-theft system.

[0002] One embodiment of the present invention relates to a semiconductor device, a display device, a light-emitting device, a power storage device, a lighting device, an electronic device, or a manufacturing method thereof.

[0003] In this specification, the term "semiconductor device" refers to any device that can function by utilizing semiconductor characteristics, and electro-optical devices, semiconductor circuits, and electronic devices are all included in the category of semiconductor devices.

[0004] In this specification, the term "power storage device" refers to elements and devices in general that have a power storage function, including, for example, power storage devices of lithium ion secondary batteries (also called secondary batteries), lithium ion capacitors, and electric double layer capacitors.

[0005] In recent years, the development of various power storage devices, such as lithium-ion secondary batteries, lithium-ion capacitors, and air batteries, has been actively pursued. In particular, lithium-ion secondary batteries, which have high output and high energy density, are applied to mobile information terminals, such as mobile phones, smartphones, and notebook computers, as well as portable music players, digital cameras, medical devices, and next-generation clean energy vehicles, such as hybrid vehicles (HVs), electric vehicles (EVs), and plug-in hybrid vehicles (PHVs). Demand for lithium-ion secondary batteries has expanded rapidly along with the development of the semiconductor industry, and they have become indispensable in the modern information society as a rechargeable energy source.

[0006] Lithium-ion secondary batteries are also being installed in electrically assisted bicycles and electric motorcycles (also called electric scooters).

[0007] In these electric vehicles, the secondary battery is detachable from the electric vehicle, and when charging, the battery is removed from the electric vehicle and charged.

[0008] An example of a block diagram of a conventional electric vehicle is shown in Figure 13. For quality control, the electric vehicle main unit 1220 is stamped or labeled with the serial number of the vehicle body or the serial number of the operation unit. The operation unit 1207 has a display unit 1208 and a power switch 1209, and when the user presses the power switch 1209, power from the secondary battery 1200 is supplied to the motor unit 1201 via the charge / discharge control unit 1203. The secondary battery unit 1210 also has a serial number labeled. In the case of electrically power-assisted bicycles in Japan, the electric vehicle main unit 1220 may be registered for theft prevention purposes, and the serial number of the vehicle body is used to prevent theft, but the serial number of the secondary battery unit 1210 is merely an individual identification number for quality control purposes.

[0009] Furthermore, a highly safe power storage system using a neural network is disclosed in Patent Document 1. Patent Document 1 discloses a power storage system in which the operation of the storage battery is stopped.

[0010] JP 2019-023853 A

[0011] Secondary batteries that can be removed from electric vehicles, such as electrically assisted bicycles or electric motorcycles, are being stolen and resold, creating a problem. Secondary batteries are consumables, and their performance deteriorates as they age. Therefore, they must be replaced after a certain number of years, making them expensive. However, compared to replacing the entire electric vehicle, simply replacing the secondary battery is more costly, so there is demand for secondary batteries alone. Furthermore, secondary batteries are merely locked with a fragile physical key, and can be easily removed by destroying the key. Furthermore, theft can result in significant losses.

[0012] Furthermore, rechargeable batteries can now be bought and sold online, making it easy for thieves to cash in on them. Thieves can also resell the batteries without using them. Furthermore, because rechargeable batteries for electrically assisted bicycles are compatible, they can be freely installed in electric vehicles of different years. Therefore, users who unknowingly purchase stolen batteries online can continue to use them.

[0013] An object of the present invention is to provide an electric vehicle and a system that can easily identify theft of a secondary battery of an electric vehicle, such as an electrically assisted bicycle, and prevent theft.

[0014] In order to prevent theft of a secondary battery that can be removed from an electric vehicle, such as an electrically assisted bicycle or an electric motorcycle, one-to-one mutual authentication is performed between the electric vehicle main unit and the secondary battery unit.

[0015] The secondary battery unit is configured to have at least a first storage unit for storing first identification information, an authentication unit, and a wireless communication unit. The electric vehicle main unit has a second storage unit for storing second identification information, and only when the authentication unit of the secondary battery unit can authenticate the first identification information, power is supplied from the secondary battery to the electrically driven part in normal mode.

[0016] If the authentication section of the secondary battery unit is unable to authenticate, it determines that the secondary battery has been stolen and switches to theft mode, displaying a warning on the display of the electric vehicle main unit or turning on a lamp on the secondary battery unit. Alternatively, it may determine that the secondary battery has experienced an abnormality and switches to abnormal mode, displaying a warning on the display of the electric vehicle main unit or turning on a lamp on the secondary battery unit.

[0017] Furthermore, if the authentication section of the secondary battery unit fails to authenticate the stolen secondary battery, the lamp may be kept lit to render the stolen secondary battery unusable, putting it into an over-discharged state. By rendering the stolen secondary battery unusable, theft through resale can be reduced.

[0018] The configuration of the invention disclosed in this specification is an electric vehicle having an electric vehicle main unit having an electric part, and a secondary battery unit that can be attached to and detached from the electric vehicle main unit, wherein the secondary battery unit has a first memory unit that stores first identification information, the electric vehicle main unit has a second memory unit that stores second identification information, and the secondary battery unit has an authentication unit that compares the first identification information with the second identification information, and a wireless communication unit that receives the first identification information and the second identification information.

[0019] In the above configuration, the secondary battery unit has a secondary battery and a charge / discharge control unit electrically connected to the secondary battery, and supplies power to the motorized unit based on a signal from the authentication unit.

[0020] In the above configuration, the first identification information and the second identification information are transmitted from the user's information terminal to the wireless communication unit. The wireless communication unit may be provided not only in the secondary battery unit but also in the electric vehicle main unit.

[0021] Furthermore, by using a server device to manage the identification number of the electric vehicle main unit or the identification number of the secondary battery unit, it is possible to determine whether or not a secondary battery has been stolen.

[0022] Furthermore, a secondary battery theft prevention system can be realized using the server device.

[0023] The secondary battery theft prevention system disclosed in this specification is configured to include an electric vehicle main unit having an electric part, a secondary battery unit that can be attached and detached to the electric vehicle main unit, and a server device that creates, registers, and manages first identification information and second identification information, wherein the secondary battery unit has a first memory unit that stores the first identification information, a wireless communication unit that can communicate with the user's information terminal, and an authentication unit, and the electric vehicle main unit has a second memory unit that stores the second identification information, and is a secondary battery theft prevention system that compares the first identification information with the second identification information, and allows output from the secondary battery unit to the electric part if authentication by the authentication unit is successful, and stops output from the secondary battery unit to the electric part if authentication fails.

[0024] In the above system configuration, the server device generates first identification information and second identification information. Specifically, the server device generates an identification number (first identification information) that serves as an encryption key based on the serial number of the electric vehicle main unit, the serial number of the secondary battery unit, and user information that identifies the individual user, and then generates an identification number (second identification information) that serves as the encryption key. Note that the number of pieces of data is not limited to three (the serial number of the electric vehicle main unit, the serial number of the secondary battery unit, and user information that identifies the individual user), and the server device may generate an identification number that serves as the encryption key based on any one of the three pieces of data. The identification numbers may be common data or may be different from each other.

[0025] The user information may be numeric data obtained from an IC chip embedded in an ID card such as a driver's license or My Number card, the telephone number of the information terminal, an email address, or an account name.

[0026] The My Number card identification number is an identification number for an individual registered with a Japanese city, town, or village, and refers to the data consisting of a 12-digit number among the multiple pieces of data registered on the IC chip built into the My Number card. Furthermore, the secondary battery theft prevention system disclosed in this specification is not limited to Japan, and if used in the United States, a social security number can be used as user information, or a personal ID number conforming to the system of each country can be used as user information.

[0027] Although there is a risk that a malicious third party may decipher the encryption key, it is preferable because it can be used to prevent theft within a certain standard. An encryption key can also be called an encryption code, and is not limited to a code whose contents are not known to a third party, but can be any combination of numbers or symbols (including alphabets), and ID information is also included.

[0028] Note that the server device may be installed overseas, so it does not matter whether it is located in Japan or not. Even if part or all of the server device is located overseas, if the user who uses it is in Japan, and even if the program (application software) to be installed is downloaded from an overseas server device, it will be considered that the user is receiving a service using the present invention. Furthermore, if a third party provides a service for individual users to use, not as a business, it will be considered that the third party is using the present invention.

[0029] Furthermore, in the above system, if authentication fails, a message is displayed indicating that the secondary battery has been stolen, or the secondary battery is made unusable.

[0030] Theft prevention is achieved by providing an authentication unit in a secondary battery unit that can be attached to or detached from the electric vehicle main unit. If the authentication unit determines that a secondary battery unit has been stolen, it is rendered unusable. The theft prevention system using the authentication unit can achieve anti-theft measures by nullifying the purpose of the secondary battery unit's theft.

[0031] FIG. 1 is a block diagram illustrating one embodiment of the present invention. FIG. 2 illustrates an example of an authentication flow illustrating one embodiment of the present invention. FIGS. 3A and 3B are circuit diagrams of an anti-theft system for a secondary battery according to one embodiment of the present invention. FIGS. 4A and 4B are circuit diagrams of a charge / discharge control circuit. FIG. 5 is a circuit diagram of a charge / discharge control circuit. FIG. 6A illustrates an example of a cylindrical secondary battery, FIG. 6B illustrates an example of a cylindrical secondary battery, FIG. 6C illustrates an example of multiple cylindrical secondary batteries, and FIG. 6D illustrates an example of a battery management system including multiple cylindrical secondary batteries. FIGS. 7A and 7B are diagrams illustrating an example of a secondary battery, and FIG. 7C is a diagram illustrating the internal state of the secondary battery. FIGS. 8A to 8C are diagrams illustrating an example of a secondary battery. FIGS. 9A and 9B are diagrams illustrating the external appearance of a secondary battery. FIGS. 10A to 10C are diagrams illustrating a method for manufacturing a secondary battery. FIG. 11A is a perspective view of a battery pack illustrating one embodiment of the present invention, and FIG. 11B is a block diagram of the battery pack. Fig. 12A is a diagram showing an electric bicycle, Fig. 12B is a diagram showing a secondary battery of the electric bicycle, and Fig. 12C is a diagram explaining an electric motorcycle. Fig. 13 is a block diagram showing a conventional example.

[0032] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it will be readily understood by those skilled in the art that various modifications can be made to the embodiments and details. Furthermore, the present invention should not be interpreted as being limited to the description of the embodiments shown below.

[0033] (Embodiment 1) In this embodiment, an electric vehicle and an anti-theft system will be described with reference to Figures 1 and 2. In this embodiment, an electric-assisted bicycle will be described as an example.

[0034] The electrically assisted bicycle is composed of an electric vehicle main unit 220 and a detachable secondary battery unit 210.

[0035] In addition to the secondary battery 200 and the charge / discharge control unit 203, the secondary battery unit 210 also has an authentication unit 215, a wireless communication unit 213, and a first memory unit 214. The charge / discharge control unit 203, authentication unit 215, wireless communication unit 213, and first memory unit 214, which are enclosed by dotted lines in FIG. 1, form a circuit group, and each IC can be mounted on a single IC board. The secondary battery unit 210 also has an identification number, specifically a serial number label or stamp. A first identification number 202a is created based on the serial number of this secondary battery unit 210, and the first memory unit 214 is provided to store this number.

[0036] Electric vehicle main unit 220 has electric section 201 and operation section 207. Electric vehicle main unit 220 also has an identification number, specifically a serial number label or stamp. A second identification number 202b is created based on the serial number of electric vehicle main unit 220, and electric vehicle main unit 220 has second storage section 204 for storing this number. Second storage section 204 may also be included in operation section 207.

[0037] Next, an example of an authentication flow in an anti-theft system for an electrically assisted bicycle using a first identification number 202a and a second identification number 202b used in the authentication unit 215 for theft prevention is shown in FIG.

[0038] 1 has a wireless communication unit 263 capable of two-way communication with a wireless communication unit 253 of an information terminal 252 owned by a user 250, and has an encrypted data creation program 261. The information terminal 252 owned by the user 250 is a personal computer, a smartphone, or a small portable information terminal (a wristwatch-type information terminal), and has a third storage unit 254 for recording various data.

[0039] User 250 downloads application software (also called an app) for authenticating the anti-theft system of the electrically assisted bicycle from server device 260 to third storage unit 254 of information terminal 252 via wireless communication unit 253. This step is shown in step S1 in FIG. 2.

[0040] Then, the manufacturing label of the electric vehicle main unit 220, the manufacturing label of the secondary battery unit 210, or the user's personal identification information 251 is read by the information terminal 252, or is manually entered by the user 250 and stored in the third storage unit 254. This step is shown in step S2 in Fig. 2. The user's personal identification information 251 may be a fingerprint, a driver's license number, or a number on a My Number card.

[0041] Then, based on these pieces of data (one or more of the manufacturing label of the electric vehicle main unit 220, the manufacturing label of the secondary battery unit 210, and the user's personal identification information 251), encryption data is created by the encryption data creation program 261 of the server device 260. This step is shown in step S3 in FIG. 2.

[0042] The encrypted data is then stored in the fourth storage unit 264 of the server device 260 and registered to function as a database corresponding to a plurality of users 250. This step is shown in step S4 of FIG.

[0043] In addition, if the capacity of the third memory unit 254 is sufficient and the information terminal 252 has a processing circuit with sufficient computing power, the encryption data creation program 261 of the server device 260 may be downloaded to the third memory unit 254, and the encryption data may be created by the information terminal 252.

[0044] The user 250 uses the information terminal 252 to record encryption data in the electric vehicle main unit 220 and the secondary battery unit 210 of the user's power-assisted bicycle. The recorded encryption data may be the same or different. Because a single electric vehicle main unit 220 may be used with two interchangeable secondary battery units 210, it is preferable that the recorded encryption data be different, as long as the encryption data is associated with each secondary battery unit by the authentication unit 215. In this case, one electric vehicle main unit 220 is designed to be compatible with multiple secondary battery units. However, one secondary battery unit 210 is only allowed to authenticate the encryption data of one electric vehicle main unit 220. For this reason, it is preferable that the first memory unit 214 of the secondary battery unit 210 be a write-only memory. In this embodiment, the first identification number 202a is written to the first memory unit 214 via the wireless communication unit 213 as encryption data. The second identification number 202b is written to the second memory unit 204 via the wireless communication unit 213 as encryption data. This step is shown in step S5 of FIG.

[0045] Although an example has been shown in which secondary battery unit 210 and electric vehicle main unit 220 are connected and data is written using one wireless communication unit 213, a wireless communication unit may be provided in electric vehicle main unit 220. Bluetooth (registered trademark) may also be used as the wireless communication unit.

[0046] In this way, the identification numbers are stored in the secondary battery unit 210 and the electric vehicle main unit 220, and advance preparations for using the electric-assisted bicycle are completed.

[0047] Next, user 250 presses power switch 209 on operating unit 207 of electric vehicle main unit 220 to use electric unit 201 of the electrically assisted bicycle. This step is shown as step S6 in Figure 2. Unless user 250 presses power switch 209, the electrically assisted bicycle operates as a normal bicycle, and only when power switch 209 is pressed to activate electric unit 201 does the user's leg strength begin to be assisted. Furthermore, for the sake of power consumption reduction and safety, secondary battery 200, which serves as the main battery, is electrically disconnected from operating unit 207 when the anti-theft system is off.

[0048] In this embodiment, when the power switch 209 is pressed, the authentication unit 215 verifies whether the combination of the first identification number 202a and the second identification number 202b is correct. This step is shown in step S7 in FIG.

[0049] Then, authentication unit 215 determines whether the authentication is successful, and if successful, permits the supply of power to motorized unit 201. This stage is shown in step S8 in Fig. 2. In this way, by pressing power switch 209 on operation unit 207, the display on display unit 208 is displayed for a certain period of time, and power from secondary battery 200 is supplied to motorized unit 201 based on a signal from authentication unit 215.

[0050] If the battery is not authenticated, it is assumed to be a stolen secondary battery, and the system switches to theft mode, making the secondary battery unusable on the user's electrically power assisted bicycle. This step is shown in step S9 in Figure 2. Making the secondary battery unusable means at least preventing the secondary battery from supplying power to the electric motor unit 201 of the electrically power assisted bicycle.

[0051] The theft mode makes the battery unusable in the electric vehicle of the user to which it is set, or displays a theft mark. The theft mode may also turn on a theft indicator lamp in addition to displaying the remaining capacity meter on the secondary battery unit 210. The theft mode may also emit a warning sound from the speaker. The theft indicator lamp or theft mode may be replaced by an abnormality indicator lamp or abnormality mode. Of course, a stolen secondary battery can be used if it is installed in the original electric vehicle that was authenticated before the theft.

[0052] In addition, as a measure to make the secondary battery unusable for the user's electric vehicle in theft mode, for example, the charge switch or discharge switch in the charge / discharge control unit 203 is turned off. Alternatively, the secondary battery may be discharged using the cell balance function of the charge / discharge control unit 203. Alternatively, the secondary battery may be discharged by keeping the theft indicator lamp illuminated. Furthermore, if a battery management system capable of regenerative charging is used, regenerative charging of the secondary battery is stopped.

[0053] Although this embodiment has been described as an example of an electrically assisted bicycle, the present invention can also be applied to an electric motorcycle. With an electrically assisted bicycle, the user 250 manually turns on the power switch to use the electric unit while riding, so authentication is performed each time the power switch is turned on. On the other hand, with an electric motorcycle, the electric unit is driven while riding, so authentication is performed before the user starts moving.

[0054] This embodiment mode can be freely combined with other embodiment modes.

[0055] (Embodiment 2) In this embodiment, an example of the charge / discharge control unit 203 that is partially different from that in Embodiment 1 will be described. The charge / discharge control unit 203 can also be called a battery management system.

[0056] FIG. 3A shows an example of a battery management system 10 constituting a part of the anti-theft system for a secondary battery according to one embodiment of the present invention. The battery management system 10 includes a charge / discharge control circuit 135, a battery 107, and an authentication unit 109. The charge / discharge control circuit 135 is electrically connected to the battery 107. Specifically, the charge / discharge control circuit 135 is electrically connected to the positive and negative electrodes of the battery 107. The battery 107 may have a positive terminal such as a positive lead or a positive tab attached thereto as the positive electrode. The battery 107 may have a negative terminal such as a negative lead or a negative tab attached thereto as the negative electrode. In this case, the charge / discharge control circuit 135 is electrically connected to the positive and negative terminals. The authentication unit 109 includes a memory. The authentication unit 109 has a function of comparing the identification number of the electric vehicle body with the identification number of the battery 107. Specifically, the authentication unit 109 has a function of comparing encrypted data stored in the memory of the electric vehicle main body (corresponding to the second identification number 202b shown in Embodiment 1) with encrypted data corresponding to the battery's serial number (corresponding to the first identification number 202a shown in Embodiment 1). The authentication unit 109 is electrically connected to the charge / discharge control circuit 135. The authentication unit 109 obtains the encrypted data stored in the memory of the electric vehicle main body from a terminal 40. The terminal 40 is electrically connected to a readout circuit for the memory of the electric vehicle main body.

[0057] 3A includes at least a voltage measurement circuit 15, a current measurement circuit 16, and a control circuit 18. The charge / discharge control circuit 135 further includes a first switch 35 and a second switch 36 electrically connected to the control circuit 18. The first switch 35 functions to stop charging in the event of overcharging, and the second switch 36 functions to stop discharging in the event of overdischarging. Furthermore, the first switch 35 can be used to stop charging the battery 107 based on a signal from the authentication unit 109.

[0058] Although not shown here, the authentication unit 109 includes a memory, a circuit for rewriting or reading data from the memory, and a wireless communication unit capable of communicating with the user's information terminal. The user can write data to the memory from the information terminal via the wireless communication unit. When writing data to the memory via the wireless communication unit, the system switches to registration mode, and power from the secondary battery is supplied to at least the charge / discharge control circuit 135, the memory of the authentication unit 109, and the memory of the electric vehicle body, but not to the electric units. The information stored in the memory is information that is rewritten infrequently. Therefore, a write-once read-only memory (ROM) may be used as the memory. Also, a well-known non-volatile oxide semiconductor random access memory (NOSRAM) may be used as the memory. Furthermore, as the memory, a known magnetoresistive random access memory (MRAM) utilizing MTJ (magnetic tunnel junction) characteristics, a known resistive random access memory (ReRAM), or a known phase-change memory may be used.

[0059] The charge / discharge control circuit 135 shown in FIG. 3B is different from that shown in FIG. 3A and is an example of a configuration in which a temperature sensor 20 is further included.

[0060] 3A and 3B, the voltage measurement circuit 15 is electrically connected to the positive and negative electrodes of the battery 107. The voltage measurement circuit 15 may be electrically connected to the positive and negative terminals.

[0061] The voltage measurement circuit 15 has a function of measuring the voltage (referred to as terminal voltage) of the battery 107, for example, a function of measuring the terminal voltage (referred to as charging voltage) when the battery 107 is being charged. The voltage measurement circuit 15 may also have a function of measuring the terminal voltage (referred to as discharging voltage) when the battery 107 is being discharged in addition to the charging voltage.

[0062] The voltage measurement circuit 15 can provide the measured voltage value to the control circuit 18. If the measured voltage value is an analog value, the analog value may be converted to digital and provided to the control circuit 18. That is, the voltage measurement circuit 15 may have a circuit that converts the analog value to digital, and this circuit can be an analog-to-digital converter (ADC). ADC configurations include a ΔΣ modulation type, a parallel comparison type (also referred to as a flash type), and a pipeline type. The ΔΣ modulation type is suitable for the voltage measurement circuit 15 because of its high resolution.

[0063] <Measurement Example 1 of Voltage Vb1> Measurement Example 1 of voltage Vb1 between the positive and negative electrodes of a secondary battery will be described using Fig. 4A. Of the charge / discharge control circuit 135 in Fig. 4A, only the voltage measurement circuit 15 is shown, and the rest is omitted. The voltage measurement circuit 15 can directly measure the voltage Vb1 between the positive and negative electrodes of the secondary battery, as shown in Fig. 4A.

[0064] <Measurement Example 2 of Voltage Vb1> As shown in FIG. 4B , the voltage measurement circuit 15 can also measure the resistively divided voltage Vb1. In FIG. 4B , only the voltage measurement circuit 15 is shown in the charge / discharge control circuit 135; the rest of the circuit is omitted. In FIG. 4B , the voltage Vb1 is divided into voltages Vb2 and Vb3 by resistive elements 122 and 123, and the voltage measurement circuit 15 can measure, for example, voltage Vb3. To be able to measure voltage Vb3, the voltage measurement circuit 15 is electrically connected between the negative electrode of the battery 107 and the resistor elements 122 and 123.

[0065] When the voltage measurement circuit 15 measures the voltage obtained by resistively dividing the voltage between the positive and negative electrodes of the battery 107, the voltage measurement circuit 15 or the control circuit 18 may estimate the voltage Vb1 between the positive and negative electrodes of the battery 107 from the resistively divided voltage.

[0066] 3A and 3B , the current measurement circuit 16 is electrically connected to the positive electrode of the battery 107, with a resistive element positioned between the connection points to measure the potential difference across the resistive element. The current measurement circuit 16 may also be electrically connected to the positive electrode terminal. Furthermore, the current measurement circuit 16 is not limited to the current measurement circuit 16, and a Hall-type current sensor may also be used.

[0067] The current measuring circuit 16 has a function of measuring the current flowing through the positive and negative electrodes of the battery 107, and preferably has a function of measuring, for example, the current (referred to as the charging current) when the battery 107 is being charged. The current measuring circuit 16 may also have a function of measuring the current (referred to as the discharging current) when the battery 107 is being discharged in addition to the charging current.

[0068] The current measurement circuit 16 can provide the measured current value to the control circuit 18. The measured current value is an analog value, but the analog value may be converted to digital and provided to the control circuit 18, and the analog-to-digital converter (ADC) described above can be used.

[0069] 3A and 3B has a function of controlling the start and stop of charging of the battery 107. Furthermore, the control circuit 18 may have a calculation function, a detection function, or a determination function. The calculation function can calculate data indicating the battery characteristics of the battery 107 from the value provided by the voltage measurement circuit 15.

[0070] <Determination Function> The determination function of the control circuit 18 enables it to determine, based on a signal obtained from the authentication unit 109, when charging should be stopped.

[0071] <Stopping Charging and Discharging> The control circuit 18 has a function of stopping charging and discharging based on a signal obtained from the authentication unit 109 .

[0072] <Charging Conditions> Constant current-constant voltage (CC-CV) charging is sometimes used to charge secondary batteries. CC-CV charging involves performing constant current charging, and then, after the upper limit of the charging voltage has been reached during constant current charging, performing constant voltage charging.

[0073] It is preferable that the charging condition from the start of charging to the end of charging be constant current charging. For example, during constant current charging, the voltage changes after charging is stopped and then resumed, making it easier to grasp the SOC (state of charge).

[0074] <Coulomb Counter> The charge / discharge control circuit 135 preferably has a function as a coulomb counter. For example, as a function of the coulomb counter, the charge / discharge control circuit 135 can calculate the cumulative amount of electricity of the battery 107 using the current measurement circuit 16 and the control circuit 18. From the calculated amount of electricity, the charge capacity and discharge capacity of the secondary battery can be calculated.

[0075] <SOC> The control circuit 18 may also have a function of analyzing the SOC using the calculated charge capacity and discharge capacity. The control circuit 18 may be a CPU (Central Processing Unit) or an MCU (Micro Controller Unit).

[0076] The control circuit 18 may include a memory circuit 19 in addition to the CPU or MCU. The memory circuit 19 can also store encrypted data of the battery (corresponding to the first identification number 202a described in Embodiment 1) used for authentication by the authentication unit 109.

[0077] <Temperature Sensor> The temperature sensor 20 shown in Fig. 3B can measure the operating temperature of the secondary battery. The temperature sensor 20 is only required to be able to measure a range from low to high temperatures. The temperature sensor 20 is preferably installed so as to be in contact with the exterior body of the battery 107 or the outer casing of the exterior body.

[0078] When the battery 107 is used at low and high temperatures, or at low and room temperatures, or at different temperatures, the information on the operating temperature obtained from the temperature sensor 20 is useful. Furthermore, even when the battery 107 is used in the same temperature range, the temperature sensor 20 can also detect any abnormality that occurs in the battery. If the secondary battery material is highly safe, the temperature sensor 20 may not be provided.

[0079] <Secondary Battery> Details of the battery 107 will be described later.

[0080] <Battery Pack> The battery management system 10B shown in Fig. 5 illustrates an example in which a charge / discharge control circuit 135 is electrically connected to m (m is a positive integer) batteries 107 connected in series. Fig. 5 illustrates an example of the battery management system 10B in which m is a natural number greater than or equal to 4, and battery 107(1), battery 107(2), battery 107(3), and battery 107(m) are shown as the first, second, third, and mth batteries of the m batteries 107. The charge / discharge control circuit 135 may be divided into m charge / discharge control circuits 135(m), but is preferably shared as shown in Fig. 5.

[0081] Furthermore, in the battery management system 10B, the voltages of the m batteries 107 can be measured using m voltage measurement circuits 15 connected to each battery. The voltage measurement circuits 15 may be shared rather than being divided into m voltage measurement circuits 15 as shown in FIG. 5. The voltage may be measured using the total voltage of the m batteries 107 connected in series (for example, the voltage between the positive electrode of battery 107(1) and the negative electrode of battery 107(m) in FIG. 5).

[0082] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0083] (Embodiment 3) An example of a cylindrical secondary battery will be described with reference to Fig. 6A. As shown in Fig. 6A, a cylindrical secondary battery 616 has a positive electrode cap (battery lid) 601 on the top surface and a battery can (external can) 602 on the side and bottom surfaces. The positive electrode cap 601 and the battery can (external can) 602 are insulated by a gasket (insulating packing) 610.

[0084] 6B is a schematic diagram showing a cross section of a cylindrical secondary battery. The cylindrical secondary battery shown in FIG. 6B has a positive electrode cap (battery lid) 601 on the top surface and a battery can (external can) 602 on the side and bottom surfaces. The positive electrode cap and battery can (external can) 602 are insulated by a gasket (insulating packing) 610.

[0085] A wound body is provided inside a hollow cylindrical battery can 602. The wound body is formed by winding a strip-shaped positive electrode 604 and a negative electrode 606 with a separator 605 sandwiched therebetween. Although not shown, the wound body is wound around a central axis. The battery can 602 is closed at one end and open at the other end. The battery can 602 can be made of metals resistant to corrosion in liquid electrolytes, such as nickel, aluminum, and titanium, or alloys thereof, or alloys of these with other metals (e.g., stainless steel). Furthermore, to prevent corrosion by the liquid electrolyte, the battery can 602 is preferably coated with nickel or aluminum. Inside the battery can 602, the wound body formed by winding the positive electrode, negative electrode, and separator is sandwiched between a pair of opposing insulating plates 608 and 609. A nonaqueous electrolyte (not shown) is poured into the battery can 602, where the wound body is provided.

[0086] Since the positive and negative electrodes used in a cylindrical storage battery are wound, it is preferable to form active materials on both sides of the current collector. While the secondary battery 616 shown in Figures 6A to 6D has a cylinder whose height is greater than its diameter, this is not limiting. A secondary battery whose diameter is greater than its height may also be used. This configuration, for example, can reduce the size of the secondary battery.

[0087] A positive electrode terminal (positive electrode current collector lead) 603 is connected to the positive electrode 604, and a negative electrode terminal (negative electrode current collector lead) 607 is connected to the negative electrode 606. Both the positive electrode terminal 603 and the negative electrode terminal 607 can be made of aluminum. The positive electrode terminal 603 is resistance-welded to a safety valve mechanism 613, and the negative electrode terminal 607 is resistance-welded to the bottom of the battery can 602. The safety valve mechanism 613 is electrically connected to the positive electrode cap 601 via a PTC (Positive Temperature Coefficient) element 611. The safety valve mechanism 613 cuts off the electrical connection between the positive electrode cap 601 and the positive electrode 604 when the increase in internal pressure of the battery exceeds a predetermined threshold. The PTC element 611 is a thermosensitive resistor whose resistance increases as the temperature increases, and the increased resistance limits the amount of current to prevent abnormal heat generation. The PTC element is made of barium titanate (BaTiO ３)-based semiconductor ceramics can be used.

[0088] 6C shows an example of a battery management system 615. The battery management system 615 has multiple secondary batteries 616. The positive electrodes of each secondary battery are in contact with and electrically connected to conductors 624 separated by insulators 625. The conductors 624 are electrically connected to a control circuit 620 via wiring 623. The negative electrodes of each secondary battery are electrically connected to the control circuit 620 via wiring 626. A protection circuit that prevents overcharging or overdischarging can be used as the control circuit 620.

[0089] 6D shows an example of a battery management system 615. The battery management system 615 has multiple secondary batteries 616, which are sandwiched between a conductive plate 628 and a conductive plate 614. The multiple secondary batteries 616 are electrically connected to the conductive plate 628 and the conductive plate 614 by wiring 627. The multiple secondary batteries 616 may be connected in parallel, in series, or in parallel and then in series. Configuring the battery management system 615 to have multiple secondary batteries 616 allows for the extraction of large amounts of power.

[0090] A plurality of secondary batteries 616 may be connected in parallel and then further connected in series.

[0091] A temperature control device may be provided between the multiple secondary batteries 616. When a secondary battery 616 is overheated, the temperature control device can cool it, and when a secondary battery 616 is too cold, the temperature control device can heat it. This makes the performance of the battery management system 615 less susceptible to the outside air temperature.

[0092] 6D , the battery management system 615 is electrically connected to a control circuit 620 via wiring 621 and wiring 622. The wiring 621 is electrically connected to the positive electrodes of the plurality of secondary batteries 616 via a conductive plate 628, and the wiring 622 is electrically connected to the negative electrodes of the plurality of secondary batteries 616 via a conductive plate 614.

[0093] [Another Example of Secondary Battery Structure] An example of the structure of a secondary battery will be described with reference to FIGS. 7 and 8. FIG.

[0094] The secondary battery 913 shown in FIG. 7A has a wound body 950 provided with terminals 951 and 952 inside a housing 930. The wound body 950 is immersed in a liquid electrolyte inside the housing 930. The terminal 952 contacts the housing 930, and the terminal 951 is not in contact with the housing 930 due to the use of an insulating material. Note that in FIG. 7A, the housing 930 is shown separated for convenience, but in reality, the wound body 950 is covered by the housing 930, and the terminals 951 and 952 extend outside the housing 930. The housing 930 can be made of a metal material (e.g., aluminum) or a resin material.

[0095] 7B, the housing 930 shown in Fig. 7A may be formed of a plurality of materials. For example, the secondary battery 913 shown in Fig. 7B has a housing 930a and a housing 930b bonded together, and a wound body 950 is provided in the area surrounded by the housing 930a and the housing 930b.

[0096] The housing 930a can be made of an insulating material, typically an organic resin. In particular, by using a material, typically an organic resin, on the surface on which the antenna is formed, it is possible to suppress shielding of the electric field by the secondary battery 913. Note that if the shielding of the electric field by the housing 930a is small, the antenna may be provided inside the housing 930a. The housing 930b can be made of, for example, a metal material.

[0097] 7C shows the structure of the wound body 950. The wound body 950 has a negative electrode 931, a positive electrode 932, and a separator 933. The wound body 950 is a wound body in which the negative electrode 931 and the positive electrode 932 are stacked on top of each other with the separator 933 sandwiched therebetween, and the laminated sheet is wound. Note that multiple layers of the negative electrode 931, the positive electrode 932, and the separator 933 may be stacked.

[0098] 8A to 8C may be used as a secondary battery 913 having a wound body 950a. The wound body 950a shown in Fig. 8A includes a negative electrode 931, a positive electrode 932, and a separator 933. The negative electrode 931 includes a negative electrode active material layer 931a. The positive electrode 932 includes a positive electrode active material layer 932a.

[0099] The separator 933 has a width wider than the negative electrode active material layer 931 a and the positive electrode active material layer 932 a, and is wound so as to overlap the negative electrode active material layer 931 a and the positive electrode active material layer 932 a. From the standpoint of safety, it is preferable that the negative electrode active material layer 931 a be wider than the positive electrode active material layer 932 a. A wound body 950 a having such a shape is preferable due to its high safety and productivity.

[0100] 8B, the negative electrode 931 is electrically connected to a terminal 951. The terminal 951 is electrically connected to a terminal 911a. The positive electrode 932 is electrically connected to a terminal 952. The terminal 952 is electrically connected to a terminal 911b.

[0101] 8C , the wound body 950a and the liquid electrolyte are covered by the housing 930 to form the secondary battery 913. It is preferable to provide a safety valve and an overcurrent protection element in the housing 930. The safety valve is a valve that opens when the inside of the housing 930 reaches a predetermined internal pressure to prevent the battery from exploding.

[0102] As shown in Fig. 8B, the secondary battery 913 may have multiple wound bodies 950a. Using multiple wound bodies 950a can result in a secondary battery 913 with a larger charge / discharge capacity. For other elements of the secondary battery 913 shown in Figs. 8A and 8B, the descriptions of the secondary battery 913 shown in Figs. 7A to 7C can be referred to.

[0103] 9A and 9B show examples of external views of a laminated secondary battery, which includes a positive electrode 503, a negative electrode 506, a separator 507, an outer casing 509, a positive electrode lead electrode 510, and a negative electrode lead electrode 511.

[0104] 10A shows an external view of a positive electrode 503 and a negative electrode 506. The positive electrode 503 has a positive electrode current collector 501, and a positive electrode active material layer 502 is formed on the surface of the positive electrode current collector 501. The positive electrode 503 also has a region where the positive electrode current collector 501 is partially exposed (hereinafter referred to as a tab region). The negative electrode 506 has a negative electrode current collector 504, and a negative electrode active material layer 505 is formed on the surface of the negative electrode current collector 504. The negative electrode 506 also has a region where the negative electrode current collector 504 is partially exposed, i.e., a tab region. The areas and shapes of the tab regions of the positive electrode and negative electrode are not limited to the example shown in FIG. 10A .

[0105] <Method of Manufacturing Laminated Secondary Battery> Here, an example of a method of manufacturing the laminated secondary battery whose external view is shown in FIG. 9A will be described with reference to FIGS. 10B and 10C.

[0106] First, the negative electrode 506, separator 507, and positive electrode 503 are stacked. FIG. 10B shows the stacked negative electrode 506, separator 507, and positive electrode 503. Here, an example is shown in which five pairs of negative electrodes and four pairs of positive electrodes are used. This can also be called a laminate consisting of a negative electrode, a separator, and a positive electrode. Next, the tab regions of the positive electrode 503 are joined together, and the positive electrode lead electrode 510 is joined to the tab region of the outermost positive electrode. For example, ultrasonic welding may be used for joining. Similarly, the tab regions of the negative electrode 506 are joined together, and the negative electrode lead electrode 511 is joined to the tab region of the outermost negative electrode.

[0107] Next, the negative electrode 506 , the separator 507 and the positive electrode 503 are arranged on the outer casing 509 .

[0108] Next, as shown in Fig. 10C, the exterior body 509 is folded at the portion indicated by the dashed line. Thereafter, the outer periphery of the exterior body 509 is joined. For example, thermocompression bonding may be used for joining. At this time, an area (hereinafter referred to as an inlet) that is not joined is provided in a part (or one side) of the exterior body 509 so that a liquid electrolyte can be introduced later.

[0109] Next, a liquid electrolyte (not shown) is introduced into the inside of the exterior body 509 through an inlet provided in the exterior body 509. The introduction of the liquid electrolyte is preferably carried out under a reduced pressure atmosphere or an inert atmosphere. Finally, the inlet is joined. In this manner, the laminated secondary battery 500 can be fabricated.

[0110] Fourth Embodiment This embodiment is an example different from the cylindrical secondary battery shown in Fig. 6D. An example is shown in which the secondary battery shown in Fig. 11A is used and applied to an electrically assisted bicycle or an electric motorcycle.

[0111] The internal structure of the battery used in an electrically assisted bicycle or an electrically powered motorcycle may be a wound type as shown in Fig. 7A or Fig. 8C, or a stacked type as shown in Fig. 9A or Fig. 9B. The battery may also be an all-solid-state battery. Using an all-solid-state battery for the battery allows for a high capacity, improved safety, and reduced size and weight.

[0112] If a single battery can store a sufficient amount of power, there is no need to prepare multiple batteries. By configuring a battery pack with multiple batteries, it is possible to extract large amounts of power. The multiple batteries may be connected in parallel, in series, or in series after being connected in parallel. Multiple batteries are also called a battery pack.

[0113] Furthermore, the battery power is mainly used to rotate the motor.

[0114] The battery also supplies power to 14V in-vehicle components (audio equipment, lamps, etc.) via a DCDC circuit. The DCDC circuit is not limited to Si (silicon) transistors using single crystal silicon, but may also use other transistors such as Ge (germanium), SiGe (silicon germanium), GaAs (gallium arsenide), GaAlAs (gallium aluminum arsenide), InP (indium phosphide), SiC (silicon carbide), ZnSe (zinc selenide), GaN (gallium nitride), and GaO ＸThe DCDC circuit may be formed using a transistor having gallium oxide (x is a real number greater than 0). Alternatively, a high electron mobility transistor (HEMT) may be used as the transistor used in the DCDC circuit. Note that the HEMT may be made of, for example, one or more materials selected from GaAs, InP, GaN, and SiGe.

[0115] The battery will be described with reference to FIG. 11A.

[0116] FIG. 11A shows an example in which five prismatic secondary batteries 1300 are combined into one battery pack 1415. The five prismatic secondary batteries 1300 are connected in series, with one electrode fixed by a fixing portion 1413 made of an insulator and the other electrode fixed by a fixing portion 1414 made of an insulator. While this embodiment shows an example in which the batteries are fixed by the fixing portions 1413 and 1414, they may also be housed in a battery housing box (also called a casing). Because it is expected that the vehicle will be subjected to external vibrations or shaking (from the road surface), it is preferable to fix multiple secondary batteries using the fixing portions 1413 and 1414 and the battery housing box. One electrode is electrically connected to the control circuit unit 1320 by wiring 1421. The other electrode is electrically connected to the control circuit unit 1320 by wiring 1422.

[0117] FIG. 11B shows an example of a block diagram of the battery pack 1415 shown in FIG. 11A.

[0118] The control circuit 1320 includes a switch unit 1324 including at least a switch for preventing overcharging and a switch for preventing overdischarging, a control circuit 1322 for controlling the switch unit 1324, and a voltage measurement unit for the battery 1301a. The control circuit 1320 sets upper and lower voltage limits for the secondary battery used and limits the upper limit of the current input and output to the outside. A voltage between the lower and upper limits of the secondary battery's voltage is within the recommended voltage range. When the voltage falls outside this range, the switch unit 1324 activates and functions as a protection circuit. The control circuit 1320 can also be called a protection circuit because it controls the switch unit 1324 to prevent overcharging and overdischarging. For example, if the control circuit 1322 detects a voltage that could cause overcharging, it turns off the switch unit 1324 to cut off the current. Furthermore, a PTC element may be provided along the charge / discharge path to cut off the current in response to a rise in temperature. The control circuit section 1320 also has an external terminal 1325 (+IN) and an external terminal 1326 (-IN).

[0119] The switch unit 1324 can be configured by combining n-channel transistors and p-channel transistors. The switch unit 1324 is not limited to a switch having a Si transistor using single crystal silicon, and may be, for example, a switch having a silicon germanium (SiGe), gallium arsenide (GaAs), gallium aluminum arsenide (GaAlAs), indium phosphide (InP), silicon carbide (SiC), zinc selenide (ZnSe), gallium nitride (GaN), or GaO Ｘ The switch section 1324 may be formed of a power transistor having gallium oxide (x is a real number greater than 0).

[0120] In addition, the regenerative energy generated by the rotation of the tires is sent to the motor via gears, and is then charged into the battery via the motor controller and the control circuit unit.

[0121] Although not shown, when the electric vehicle is connected to an external charger, the charger's outlet or charger's connection cable is electrically connected to the control circuit 1320. Power supplied from the external charger is charged to the battery 1301a via the control circuit 1320. Some chargers are provided with a control circuit, and although the functions of the control circuit 1320 may not be used, it is preferable to charge the battery 1301a via the control circuit 1320 to prevent overcharging. The charger's outlet or charger's connection cable may also be provided with a control circuit. The control circuit 1320 is sometimes called an ECU (Electronic Control Unit). The ECU is connected to a CAN (Controller Area Network) provided in the electric vehicle. CAN is one of the serial communication standards used as an in-vehicle LAN. An encryption-enabled communication standard called CAN-FD may also be used. The ECU includes a microcomputer. The ECU uses a CPU or a GPU.

[0122] The external chargers installed at the charging stations are available with 100V outlets, 200V outlets, and three-phase 200V, 50kW outlets. It is also possible to charge using a contactless power supply system that receives power from external charging equipment.

[0123] When rapid charging is performed, a secondary battery that can withstand high voltage charging is desired in order to charge in a short time.

[0124] The content of this embodiment mode can be combined with the content of other embodiment modes as appropriate.

[0125] (Embodiment 5) In this embodiment, an example in which an anti-theft system according to one embodiment of the present invention is mounted on a motorcycle or a bicycle will be described.

[0126] 12A is an example of an electric bicycle using the anti-theft system of one embodiment of the present invention. The anti-theft system of one embodiment of the present invention can be applied to an electric bicycle 8700 shown in FIG. 12A. The power storage device of one embodiment of the present invention includes, for example, a plurality of batteries, a charge / discharge control unit, and an authentication unit.

[0127] The electric bicycle 8700 includes a power storage device 8702. The power storage device 8702 can supply electricity to a motor (electric unit) that assists the rider. The power storage device 8702 is portable and is shown removed from the bicycle in FIG. 12B, where it corresponds to a secondary battery unit. The power storage device 8702 also includes multiple built-in batteries 8701, and the remaining battery charge can be displayed on a display unit 8703. If authentication by the authentication unit fails and the bicycle enters theft mode, the display unit 8703 displays that the battery has been stolen. The power storage device 8702 also includes a charge / discharge control unit 8704 that can control charging or detect abnormalities in the secondary battery. The charge / discharge control unit 8704 is electrically connected to the positive and negative electrodes of the battery 8701. The electric bicycle 8700 also includes an operation unit 8712 provided on the handle. The operation unit 8712 has a display unit 8713, a power switch 8714, and a power storage device 8711. The charge / discharge control unit 8704 may have a storage unit that can store encrypted data.

[0128] 12C shows an example of a two-wheeled vehicle using the anti-theft system of one embodiment of the present invention. An electric scooter 8600 shown in FIG. 12C includes a secondary battery unit 8602, a side mirror 8601, a turn signal light 8603, and a display unit 8605. The secondary battery unit 8602 can supply electricity to the turn signal light 8603.

[0129] 12C is capable of storing a secondary battery unit 8602 in under-seat storage 8604. The secondary battery unit 8602 can be stored in under-seat storage 8604 even if the under-seat storage 8604 is small. The secondary battery unit is detachable from the main body of the electric scooter 8600.

[0130] The secondary battery unit 8602 has an authentication unit, a wireless communication unit, and a first storage unit in addition to a secondary battery and a charge / discharge control unit. The first storage unit can store encrypted data corresponding to the serial number of the secondary battery.

[0131] The main body of the electric scooter 8600 has a second storage unit that can store encrypted data corresponding to the chassis number (body number). In addition, a serial number is also engraved on the electric motor of the electric scooter 8600, and this number may be used in the anti-theft system of one embodiment of the present invention.

[0132] The authentication unit of the secondary battery unit 8602 can verify whether the secondary battery unit 8602 is stolen or not by comparing the data in the first memory unit with the data in the second memory unit when the electric scooter 8600 starts to travel. If authentication is not possible, the supply of power from the secondary battery unit 8602 to the electric motor is stopped, making it impossible to travel. Furthermore, if authentication is not possible, the secondary battery of the secondary battery unit 8602 may be discharged to make the secondary battery unusable.

[0133] The electric scooter 8600 main unit may also be provided with a wireless communication unit, and the display unit 8605 may be configured to display the chassis number (body number) of the electric scooter 8600, and authentication may be performed via the user's information terminal and the wireless communication unit of the electric scooter 8600 main unit. In this case, the user's information terminal can authenticate both the electric scooter 8600 main unit and the secondary battery unit 8602.

[0134] The content of this embodiment mode can be combined with the content of other embodiment modes as appropriate.

[0135] 10: Battery management system, 10B: Battery management system, 15: Voltage measurement circuit, 16: Current measurement circuit, 18: Control circuit, 19: Memory circuit, 20: Temperature sensor, 35: Switch, 36: Switch, 40: Terminal, 107: Battery, 109: Authentication unit, 122: Resistance element, 123: Resistance element, 135: Charge / discharge control circuit, 200: Secondary battery, 201: Motorized unit, 202a: Identification number, 202b: Identification number, 203: Charge / discharge control unit, 204: Memory unit, 207: Operation unit, 208: Display unit, 209: Power switch, 210: Secondary battery unit, 213: Wireless communication unit 214: memory unit, 215: authentication unit, 220: electric vehicle main unit, 250: user, 251: personal identification information, 252: information terminal, 253: wireless communication unit, 254: memory unit, 260: server device, 261: encryption data creation program, 263: wireless communication unit, 264: memory unit, 500: secondary battery, 501: positive electrode current collector, 502: positive electrode active material layer, 503: positive electrode, 504: negative electrode current collector, 505: negative electrode active material layer, 506: negative electrode, 507: separator, 509: exterior body, 510: positive electrode lead electrode, 511: negative electrode lead electrode, 601: positive electrode cap, 602: battery can, 6 03: positive electrode terminal, 604: positive electrode, 605: separator, 606: negative electrode, 607: negative electrode terminal, 608: insulating plate, 609: insulating plate, 611: PTC element, 613: safety valve mechanism, 614: conductive plate, 615: battery management system, 616: secondary battery, 620: control circuit, 621: wiring, 622: wiring, 623: wiring, 624: conductor, 625: insulator, 626: wiring, 627: wiring, 628: conductive plate, 911a: terminal, 911b: terminal, 913: secondary battery, 930: housing, 930a: housing, 930b: housing, 931: negative electrode, 931a: negative electrode active material layer, 932: positive electrode, 932a: positive electrode active material layer, 933: separator, 950: wound body, 950a: wound body, 951: terminal, 952: terminal, 1200: secondary battery, 1201: motorized unit, 1203: charge / discharge control unit, 1207: operation unit, 1208: display unit, 1209: power switch, 1210: secondary battery unit, 1220: electric vehicle main unit, 1300: prismatic secondary battery, 1301a: battery, 1320: control circuit unit, 1322: control circuit, 1324: switch unit, 1325: external terminal, 1326: external terminal, 1413: fixing unit, 1414: fixing unit, 1415: battery pack,1421: Wiring, 1422: Wiring, 8600: Electric scooter, 8601: Side mirror, 8602: Secondary battery unit, 8603: Turn signal light, 8604: Under-seat storage, 8605: Display unit, 8700: Electric bicycle, 8701: Battery, 8702: Power storage device, 8703: Display unit, 8704: Charge / discharge control unit, 8711: Power storage device, 8712: Operation unit, 8713: Display unit, 8714: Power switch,

Claims

1. an electric vehicle main unit having an electric unit; a secondary battery unit that is detachable from the electric vehicle main unit, the secondary battery unit has a first storage unit that stores first identification information; the electric vehicle main unit has a second storage unit that stores second identification information, the secondary battery unit includes an authentication unit that compares the first identification information with the second identification information, and a wireless communication unit that receives the first identification information and the second identification information; The first identification information and the second identification information are transmitted from an information terminal of a user to the wireless communication unit of the electric vehicle.

2. 2. The electric vehicle according to claim 1, wherein the electric vehicle is an electrically assisted bicycle or an electric motorcycle.

3. an electric vehicle main unit having an electric unit; a secondary battery unit that is detachable from the electric vehicle main unit; a server device that creates, registers, and manages first identification information and second identification information; the secondary battery unit has a first storage unit that stores the first identification information, a wireless communication unit that can communicate with a user's information terminal, and an authentication unit; the electric vehicle main unit has a second storage unit that stores the second identification information, A secondary battery theft prevention system that compares the first identification information with the second identification information, and allows output from the secondary battery unit to the electric part if authentication by the authentication unit is successful, and stops output from the secondary battery unit to the electric part if authentication fails.

4. 4. The secondary battery theft prevention system according to claim 3, wherein the server device creates the first identification information and the second identification information based on user information, the serial number of the secondary battery unit, or the serial number of the electric vehicle main unit.

5. 4. The secondary battery theft prevention system according to claim 3, further comprising, if the authentication fails, displaying that the secondary battery unit has been stolen or disabling the secondary battery.

6. 4. The secondary battery theft prevention system according to claim 3, wherein the first identification information and the second identification information are the same.

7. 4. The secondary battery theft prevention system according to claim 3, wherein the first identification information and the second identification information are coded data.