Electric storage pack, electric vehicle, and charging device

Abstract

A control unit (12) of an electricity storage pack (10) carries out communication for authentication based on a pattern of current flowing through a power line with a control unit (32) of an electric mobile body (30) in a condition in which the electricity storage pack (10) is installed in the electric mobile body. The control unit (12) of the electricity storage pack (10) measures contact resistance between the electricity storage pack (10) and the electric mobile body on the basis of voltage of the power line at the electricity storage pack (10) side, voltage of the power line at the electric mobile body side which is received from the control unit (32) of the electric mobile body, and current during communication for authentication based on a pattern of current flowing through the power line.

Description

[Technical field]

[0001] The present disclosure relates to an electricity storage pack that is detachable from an electric vehicle, an electric vehicle, and a charging device. [Background technology]

[0002] In recent years, electric motorcycles (electric scooters) and electric bicycles have become popular. Electric motorcycles and electric bicycles usually use a removable, portable battery pack. When batteries are used as the power source for a motorcycle (scooter), it takes longer to replenish energy than when liquid fuels such as gasoline are used (charging time is longer than refueling time).

[0003] Therefore, it is conceivable to develop a system that, when the remaining capacity of a battery pack becomes low, shortens the time it takes to replenish energy by exchanging the battery pack with the low remaining capacity for a pre-charged battery pack at the nearest charging station.

[0004] In order to reduce the number of terminals on the battery pack, it is possible to wirelessly transmit and receive control signals between the battery pack and the vehicle or charger. In the above-mentioned mechanism involving battery pack replacement, if a battery pack that wirelessly transmits and receives control signals is used, a situation may arise where multiple vehicles or multiple chargers are present within the range where wireless communication with the battery pack is possible.

[0005] In such a situation, the control unit of a vehicle may mistakenly control a battery pack installed in another nearby vehicle. Also, the control unit of a charger may mistakenly control a battery pack that should not be controlled and that is installed in another charging slot, without controlling a battery pack that should be controlled and that is installed in one charging slot. In such a case, the safety and security of the entire charging system cannot be guaranteed.

[0006] The inventors have therefore developed a method for correctly identifying a battery pack attached to a vehicle or a charging device by transmitting identification information using the pattern of current flowing through a power line from a vehicle or a charging device to the battery pack, and then looping back the identification information from the battery pack to the vehicle or charging device via wireless communication.

[0007] Patent Document 1 discloses a technology that removes the current sensing resistor by detecting overcurrent using a reference voltage circuit that is equal to the product of the ON resistance of a switch circuit connected between a secondary battery and an external power supply terminal and the overcurrent value. This technology is not for overcurrent protection during the authentication process when the battery pack is attached. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 6-284594 Summary of the Invention [Problem to be solved by the invention]

[0009] The present disclosure has been made in consideration of these circumstances, and has an object to provide a technique for efficiently measuring the contact resistance between an electricity storage pack and an electric vehicle or a charging device after the electricity storage pack is attached to the electric vehicle or a charging device. [Means for solving the problem]

[0010] In order to solve the above problems, an aspect of the power storage pack disclosed herein includes a power storage unit for supplying power to an electric vehicle, and a control unit for the electric vehicle with the power storage pack attached to the electric vehicle, and a control unit for performing authentication communication based on a pattern of a current flowing through a power line. The control unit of the power storage pack measures contact resistance between the power storage pack and the electric vehicle based on a voltage of the power line on the power storage pack side, a voltage of the power line on the electric vehicle side received from the control unit of the electric vehicle, and a current when performing authentication communication based on the pattern of the current flowing through the power line. Effect of the Invention

[0011] According to the present disclosure, after the electricity storage pack is attached to an electric vehicle or a charging device, the contact resistance between the two can be efficiently measured. [Brief description of the drawings]

[0012] [Figure 1] 1 is a conceptual diagram of a vehicle system using a replaceable battery pack according to an embodiment; [Diagram 2] 1 is a diagram illustrating a configuration example of a charging device according to an embodiment; [Diagram 3] 1 is a diagram illustrating an example of the configuration of a vehicle according to an embodiment; [Figure 4] 1 is a diagram showing an example of a system configuration of a battery pack mounted on a vehicle and a vehicle control unit according to an embodiment; [Diagram 5] 4 is a diagram showing a basic concept of a process in which a vehicle control unit authenticates a battery pack installed in a mounting slot of the vehicle. FIG. [Figure 6] 10 is a diagram showing a schematic flow of assigning an ID to a replaced battery pack when the battery pack installed in the installation slot of the vehicle is replaced. FIG. [Figure 7] FIG. 1 is a sequence diagram showing a detailed process flow when replacing a battery pack mounted in a mounting slot of a vehicle (part 1). [Figure 8] FIG. 2 is a sequence diagram showing a detailed process flow when replacing a battery pack mounted in a mounting slot of a vehicle (part 2). [Figure 9] 8 is a sequence diagram (part 1) showing a process flow according to a modified example of the process shown in FIG. 7. FIG. [Figure 10] 9 is a sequence diagram (part 2) showing a process flow according to a modified example of the process shown in FIG. 8. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] 1 is a conceptual diagram of a vehicle system 1 using a replaceable battery pack 10 according to an embodiment. The vehicle system 1 uses a plurality of battery packs 10, at least one charging device 20, and a plurality of vehicles 30. In this embodiment, the vehicle 30 is assumed to be an electric motorcycle (electric scooter).

[0014] The battery pack 10 is a removable, portable, and replaceable battery pack, and can be attached to the attachment slot of the vehicle 30 or the charging slot of the charging device 20. The battery pack 10 is charged while attached to the charging slot of the charging device 20. The charged battery pack 10 is removed by a user (usually the driver of the vehicle 30) and attached to the attachment slot of the vehicle 30. The battery pack 10 attached to the attachment slot of the vehicle 30 discharges while the vehicle 30 is running, and the remaining capacity decreases as the battery pack 10 is discharged. The battery pack 10 with the reduced remaining capacity is removed by the user and attached to the charging slot of the charging device 20. The user removes a charged battery pack 10 from another charging slot of the charging device 20 and attaches it to the attachment slot of the vehicle 30. By this operation, the battery pack 10 with the reduced remaining capacity is replaced with the charged battery pack 10. This eliminates the need for the user to wait while the battery pack 10 is being charged, and allows the vehicle 30 to resume running in a short time.

[0015] In this method, the battery pack 10 is frequently attached and detached, which makes it easier for the connector of the battery pack 10, which comes into contact with the connector of the mounting slot of the vehicle 30 or the connector of the charging slot of the charging device 20, to deteriorate. As a countermeasure to this, in this embodiment, control signals are exchanged between the battery pack 10 and the vehicle 30 or the charging device 20 via wireless communication. This makes it possible to eliminate terminals for communication lines from the connector. It is sufficient that the connector is provided with terminals for power lines. In this embodiment, wired communication via a connector is not used to exchange control signals, so it is possible to prevent the control signals from being blocked due to connector defects.

[0016] Short-range wireless communication is used for wireless communication between the vehicle 30 and the battery pack 10, wireless communication between the charging device 20 and the battery pack 10, and wireless communication between the vehicle 30 and the charging device 20. As short-range wireless communication, Bluetooth (registered trademark), Wi-Fi (registered trademark), infrared communication, etc. can be used. In the following, in this embodiment, it is assumed that BLE (Bluetooth (registered trademark) Low Energy) is used as the short-range wireless communication.

[0017] BLE is an extended standard of Bluetooth (registered trademark), and is a low-power short-range wireless communication standard that uses the 2.4 GHz band. BLE consumes so little power that it can be operated for several years on a single button battery, making it suitable for battery operation, and the impact on the remaining capacity of the battery pack 10 can be considered to be almost negligible. In addition, since many BLE communication modules are shipped on the market, they can be obtained at low cost. BLE also has high compatibility with smartphones, and can provide various services in conjunction with smartphones.

[0018] When a general class 2 device is used, the radio wave reach of BLE is about 10 m. Therefore, a situation may occur where a plurality of vehicles 30, a plurality of battery packs 10, and a charging device 20 are present within the communication range of BLE. Since the charging device 20 is provided with a plurality of charging slots, the charging device 20 needs to wirelessly communicate with each of the plurality of battery packs 10 attached to the plurality of charging slots. That is, a 1:N network is configured between the charging device 20 and the plurality of battery packs 10. Similarly, when the vehicle 30 is provided with a plurality of attachment slots, the vehicle 30 needs to wirelessly communicate with each of the plurality of battery packs 10 attached to the plurality of attachment slots. That is, a 1:N network is configured between the vehicle 30 and the plurality of battery packs 10.

[0019] Therefore, a mechanism is required to ensure that the battery pack 10 attached to a specific charging slot of the charging device 20 is the same as the battery pack 10 of a specific communication partner of the charging device 20. Similarly, a mechanism is required to ensure that the battery pack 10 attached to a specific attachment slot of the vehicle 30 is the same as the battery pack 10 of a specific communication partner of the vehicle 30. In this embodiment, identification information (ID) is used to confirm the identity of the physically connected battery pack 10 and the battery pack 10 connected by wireless communication. This identification information (ID) may be temporal identification information. Note that the identification information (ID) may include identification information unique to each device.

[0020] 2 is a diagram showing an example of the configuration of charging device 20 according to an embodiment. Charging device 20 includes charging stand 21, control unit 22, display unit 27, operation unit 28, and charging unit 29. Control unit 22 includes at least processing unit 23, antenna 25, and wireless communication unit 26.

[0021] The charging stand 21 has a plurality of charging slots SLc1-SLc8 for mounting a plurality of battery packs 10. In the example shown in Fig. 2, the number of charging slots is eight, but the number of charging slots may be two or more, for example, four.

[0022] Each of the charging slots SLc1-SLc8 has a connector including a positive terminal and a negative terminal, and when the battery pack 10 is attached, it is electrically connected to the positive terminal and the negative terminal included in the connector of the battery pack 10. The negative terminal portion included in the connector of each of the charging slots SLc1-SLc8 and the negative terminal portion included in the connector of the battery pack 10 may each be configured as a solid GND. In that case, the pin included in the connector of the battery pack 10 can be reduced to a single positive terminal pin, and the protruding parts of the connector that are prone to malfunction can be reduced.

[0023] The processing unit 13 (see FIG. 4) of each battery pack 10 mounted on the charging stand 21 transmits and receives control signals to and from the processing unit 23 in the control unit 22 using short-range wireless communication and power lines. A specific method for transmitting and receiving control signals between them will be described later.

[0024] The positive and negative terminals of each of the charging slots SLc1-SLc8 are connected to the positive and negative terminals, respectively, of a charging unit 29. The charging unit 29 is connected to the commercial power system 2 and is capable of charging the battery pack 10 attached to the charging stand 21. The charging unit 29 generates DC power by full-wave rectifying the AC power supplied from the commercial power system 2 and smoothing the power with a filter.

[0025] Relays (not shown) are provided between the positive and negative terminals of charging unit 29 and the positive and negative terminals of each of the charging slots SLc1-SLc8. Processing unit 23 controls the on (closed) / off (open) of the relays to control the conduction / cutoff of each of the charging slots SLc1-SLc8.

[0026] A DC / DC converter (not shown) may be provided between the positive and negative terminals of the charging unit 29 and the positive and negative terminals of each of the charging slots SLc1-SLc8. In this case, the processing unit 23 can control the charging voltage or charging current of each battery pack 10 by controlling the DC / DC converter. For example, constant current (CC) charging or constant voltage (CV) charging can be performed. The DC / DC converter may be provided in the battery pack 10. If an AC / DC converter is installed in the battery pack 10, the battery pack 10 can also be charged with AC power from the charging unit 29.

[0027] The processing unit 23 is configured, for example, by a microcomputer. The wireless communication unit 26 executes short-range wireless communication processing. In this embodiment, the wireless communication unit 26 is configured by a BLE module, and the antenna 25 is configured by a chip antenna or a pattern antenna built into the BLE module. The wireless communication unit 26 outputs data received by short-range wireless communication to the processing unit 23, and transmits data input from the processing unit 23 by short-range wireless communication.

[0028] The processing unit 23 can acquire battery status information from the battery pack 10 attached to the charging stand 21. As the battery status information, at least one of the voltage, current, temperature, SOC (State Of Charge), and SOH (State Of Health) of the multiple cells E1-En (see FIG. 4) in the battery pack 10 can be acquired.

[0029] The display unit 27 includes a display and displays guidance on the display to a user (usually the driver of the vehicle 30) who uses the charging device 20. The operation unit 28 is a user interface such as a touch panel and receives operations from the user. The charging device 20 may further include a speaker (not shown) and output audio guidance to the user from the speaker.

[0030] 3 is a diagram showing an example of the configuration of a vehicle 30 according to an embodiment. The vehicle 30 includes a battery mounting unit 31, a vehicle control unit 32, a meter panel 39, an inverter 310, a motor 311, and tires 312. The vehicle control unit 32 includes at least a processing unit 33, an antenna 35, and a wireless communication unit 36.

[0031] The battery mounting section 31 has at least one mounting slot SLa1-SLa2 for mounting at least one battery pack 10. In the example shown in Fig. 3, the number of mounting slots is two, but the number of mounting slots may be one, or may be three or more.

[0032] Each of the mounting slots SLa1-SLa2 has a connector including a positive terminal and a negative terminal, and when the battery pack 10 is mounted, it is electrically connected to the positive terminal and the negative terminal included in the connector of the battery pack 10. The negative terminal portion included in the connector of each of the mounting slots SLa1-SLa2 may be configured as a solid GND.

[0033] The processing unit 13 (see FIG. 4) of each battery pack 10 mounted in the battery mounting unit 31 transmits and receives control signals to and from the processing unit 33 in the vehicle control unit 32 by using short-range wireless communication and power lines. A specific method of transmitting and receiving control signals between them will be described later.

[0034] The positive terminals of the mounting slots SLa1-SLa2 are connected to the positive power bus, and the negative terminals of the mounting slots SLa1-SLa2 are connected to the negative power bus. Therefore, the battery packs 10 mounted in the mounting slots SLa1-SLa2 are electrically connected in parallel. Therefore, the capacity increases as the number of battery packs 10 mounted in the battery mounting section 31 increases. Note that the battery packs 10 mounted in the mounting slots SLa1-SLa2 may be electrically connected in series. In this case, the output voltage can be increased.

[0035] The positive and negative terminals of the battery mounting unit 31 are connected to the positive and negative terminals of the inverter 310 via a main relay RYm. The main relay RYm functions as a contactor between the vehicle 30 and the battery pack 10. The processing unit 33 controls the on / off of the main relay RYm to control the conduction / cutoff between the vehicle 30 and the battery pack 10.

[0036] During power running, the inverter 310 converts DC power supplied from the battery pack 10 mounted in the battery mounting section 31 into AC power and supplies it to the motor 311. During regeneration, the inverter 310 converts AC power supplied from the motor 311 into DC power and supplies it to the battery pack 10 mounted in the battery mounting section 31. The motor 311 is a three-phase AC motor, and during power running, it rotates according to the AC power supplied from the inverter 310. During regeneration, it converts rotational energy generated by deceleration into AC power and supplies it to the inverter 310. The rotating shaft of the motor 311 is connected to the rotating shaft of a tire 312 of the rear wheel. A transmission may be provided between the rotating shaft of the motor 311 and the rotating shaft of the tire 312.

[0037] The vehicle control unit 32 is a vehicle ECU (Electronic Control Unit) that controls the entire vehicle 30. The processing unit 33 of the vehicle control unit 32 is composed of a microcomputer. The wireless communication unit 36 ​​executes short-range wireless communication processing. In this embodiment, the wireless communication unit 36 ​​is composed of a BLE module, and the antenna 35 is composed of a chip antenna or a pattern antenna built into the BLE module. The wireless communication unit 36 ​​outputs data received by short-range wireless communication to the processing unit 33, and transmits data input from the processing unit 33 by short-range wireless communication.

[0038] The processing unit 33 can acquire battery status information from the battery pack 10 mounted in the battery mounting unit 31. As the battery status information, at least one of information on the voltage, current, temperature, SOC, and SOH of the multiple cells E1-En (see FIG. 4) in the battery pack 10 can be acquired. The processing unit 33 can also acquire the speed of the vehicle 30.

[0039] The meter panel 39 displays status information of the vehicle 30. For example, it displays the speed of the vehicle 30 and the remaining capacity (SOC) of the battery pack 10. The driver can see the remaining capacity (SOC) of the battery pack 10 displayed on the meter panel 39 and determine the need to replace the battery pack 10.

[0040] Fig. 4 is a diagram showing an example of a system configuration of a battery pack 10 mounted on a vehicle 30 and a vehicle control unit 32 according to an embodiment. The example shown in Fig. 4 shows a state in which two battery packs 10a and 10b are mounted in a battery mounting unit 31 of the vehicle 30 (see Fig. 3).

[0041] The battery pack 10 includes a battery module 11 and a battery control unit 12. The battery module 11 is connected to a power line that internally connects a positive terminal Tp and a negative terminal Tm of the battery pack 10. The positive terminal Tp of the battery pack 10 is connected to a positive power bus via a slot relay RYs, and the negative terminal Tm of the battery pack 10 is connected to a negative power bus. The positive power bus and the negative power bus are connected to an inverter 310 via a main relay RYm (see FIG. 3).

[0042] The battery module 11 includes a plurality of cells E1-En connected in series. The battery module 11 may be configured by connecting a plurality of battery modules in series or in series-parallel. The cells may be lithium-ion battery cells, nickel-metal hydride battery cells, lead battery cells, etc. In the following description, an example is assumed in which lithium-ion battery cells (nominal voltage: 3.6-3.7V) are used. The number of cells E1-En connected in series is determined according to the drive voltage of the motor 311.

[0043] A current sensor 17 is installed on a power line that internally connects the positive terminal Tp and the negative terminal Tm of the battery pack 10. The current sensor 17 is installed at a position closer to the negative terminal Tm than the power relay RYp. The current sensor 17 measures the current flowing through the battery module 11 and outputs the measured current value to the processing unit 13 of the battery control unit 12. The current sensor 17 can be configured, for example, by a combination of a shunt resistor, a differential amplifier, and an A / D converter. Note that a Hall element may be used instead of the shunt resistor.

[0044] The battery control unit 12 includes a processing unit 13, a voltage measurement unit 14, an antenna 15, and a wireless communication unit 16. A plurality of voltage measurement lines connect the voltage measurement unit 14 to each node of the plurality of cells E1-En connected in series. The voltage measurement unit 14 measures the voltage of each cell E1-En by measuring the voltage between each two adjacent voltage measurement lines. The voltage measurement unit 14 transmits the measured voltage value of each cell E1-En to the processing unit 13.

[0045] Since the voltage measurement unit 14 has a high voltage relative to the processing unit 13, the voltage measurement unit 14 and the processing unit 13 are connected in an insulated state by a communication line. The voltage measurement unit 14 can be configured with an ASIC (Application Specific Integrated Circuit) or a general-purpose analog front-end IC. The voltage measurement unit 14 includes a multiplexer and an A / D converter. The multiplexer outputs the voltage between two adjacent voltage measurement lines to the A / D converter in order from top to bottom. The A / D converter converts the analog voltage input from the multiplexer into a digital value.

[0046] Although not shown in Fig. 4, at least one temperature sensor is installed near the cells E1-En. The temperature sensor measures the temperatures of the cells E1-En and outputs the measured temperature values ​​to the processing unit 13. The temperature sensor can be configured, for example, by a combination of a thermistor, a voltage dividing resistor, and an A / D converter.

[0047] In addition, if an A / D converter is installed in the processing unit 13 and an analog input port is provided in the processing unit 13, the output values ​​of the current sensor 17 and the temperature sensor can be input to the processing unit 13 as analog values.

[0048] The fitting detection unit 18 detects the fitting state between the connector of the battery pack 10 and the connector of the battery mounting unit 31 of the vehicle 30. For example, the connector on the battery pack 10 side may be a female connector, and the connector on the battery mounting unit 31 side of the vehicle 30 may be a male connector. The fitting detection unit 18 outputs an activation signal according to the connection state between the two to the processing unit 13. The activation signal is specified as a binary signal, and an ON signal is output when the two are connected, and an OFF signal is output when the two are separated. The fitting detection unit 18 can be configured, for example, by a reed switch. In this case, the fitting detection unit 18 magnetically determines whether the two are connected. A sensor that mechanically detects whether the two are connected may be used.

[0049] The wireless communication unit 16 executes short-range wireless communication processing. In this embodiment, the wireless communication unit 16 is configured with a BLE module, and the antenna 15 is configured with a chip antenna or a pattern antenna built into the BLE module. The wireless communication unit 16 outputs data received by short-range wireless communication to the processing unit 13, and transmits data input from the processing unit 13 by short-range wireless communication.

[0050] The processing unit 13 is composed of a microcomputer. The processing unit 13 starts up when the start signal input from the fitting detection unit 18 turns on, and shuts down when the start signal turns off. Instead of shutting down, the processing unit 13 may go into a standby state or a sleep state.

[0051] The processing unit 13 manages the states of the cells E1-En based on the voltage, current, and temperature values ​​of the cells E1-En measured by the voltage measurement unit 14, the current sensor 17, and the temperature sensor. For example, when an overvoltage, an undervoltage, an overcurrent, a high temperature abnormality, or a low temperature abnormality occurs, the processing unit 13 turns off the power relay RYp to protect the cells E1-En.

[0052] The processing unit 13 can estimate the SOC and SOH of each of the multiple cells E1-En. The processing unit 13 can estimate the SOC by an OCV (Open Circuit Voltage) method or a current integration method. The SOH is defined as the ratio of the current full charge capacity to the initial full charge capacity, and the lower the value (the closer to 0%), the more the deterioration has progressed. The SOH may be obtained by measuring the capacity by full charge and discharge, or by adding up the storage deterioration and cycle deterioration. The storage deterioration can be estimated based on the SOC, temperature, and storage deterioration rate. The cycle deterioration can be estimated based on the SOC range, temperature, current rate, and cycle deterioration rate used. The storage deterioration rate and cycle deterioration rate can be derived in advance by experiments or simulations. The SOC, temperature, SOC range, and current rate can be obtained by measurement.

[0053] SOH can also be estimated based on its correlation with the cell's internal resistance. The internal resistance can be estimated by dividing the voltage drop that occurs when a certain current flows through the cell for a certain time by the current value. The internal resistance decreases as the temperature increases, and increases as the SOH decreases.

[0054] 4, the vehicle control unit 32 includes a processing unit 33, a relay control unit 33r, a voltage sensor 34, a current sensor 37, an antenna 35, a wireless communication unit 36, and a pack detection unit 38p. In response to instructions from the processing unit 33, the relay control unit 33r controls the on / off of each of the main relay RYm, the first slot relay RYsa, and the second slot relay RYsb.

[0055] The first fitting detection unit 38a detects the fitting state between the connector of the first mounting slot SLa1 of the battery mounting unit 31 and the connector of the first battery pack 10a, and outputs a detection signal indicating the presence or absence of fitting to the pack detection unit 38p. Similarly, the second fitting detection unit 38b detects the fitting state between the connector of the second mounting slot SLa2 of the battery mounting unit 31 and the connector of the second battery pack 10b, and outputs a detection signal indicating the presence or absence of fitting to the pack detection unit 38p. The first fitting detection unit 38a and the second fitting detection unit 38b may detect the presence or absence of connection with the connector on the battery pack 10 side by a magnetic method or a mechanical method.

[0056] The pack detection unit 38p outputs an activation signal corresponding to the multiple detection signals input from the multiple mating detection units 38a, 38b to the processing unit 33. When at least one of the multiple detection signals indicates a connected state, the pack detection unit 38p outputs an activation signal including the slot number of the connected state. When all of the multiple detection signals indicate a non-connected state, the pack detection unit 38p controls the activation signal to an off state.

[0057] The processing unit 33 starts up when the start-up signal input from the pack detection unit 38p turns on, and shuts down when the start-up signal turns off. Instead of shutting down, the processing unit 33 may go into a standby state or a sleep state.

[0058] A discharge path is provided between the positive power bus and the negative power bus. A fuse F1, a resistor R1, and a discharge switch SWd are connected in series on the discharge path. A voltage sensor 34 is provided to measure the voltage between the positive power bus and the negative power bus. The voltage sensor 34 outputs the measured voltage value to a processing unit 33 of the vehicle control unit 32. A current sensor 37 is provided on the discharge path. The current sensor 37 measures the current flowing through the discharge path and outputs the measured current value to the processing unit 33 of the vehicle control unit 32. The processing unit 33 can establish conduction between the positive power bus and the negative power bus by turning on the discharge switch SWd.

[0059] The processing unit 33 of the vehicle control unit 32 can exchange control signals with the processing unit 13 of the battery control unit 12 using short-range wireless communication.

[0060] Further, the processing unit 33 of the vehicle control unit 32 can transmit control information to the processing unit 13 of the battery control unit 12 via a wired path. When transmitting control information to the processing unit 13 of the first battery pack 10a via a wired path, the processing unit 33 of the vehicle control unit 32 turns on the first slot relay RYsa and turns off the second slot relay RYsb. In this state, the processing unit 33 controls the discharge switch SWd to be turned on / off according to a pulse pattern indicating the control information. As a result, a discharge current including the pulse pattern flows from the positive electrode of the first battery pack 10a to the negative electrode of the first battery pack 10a via the above-mentioned discharge path. The current sensor 17 of the first battery pack 10a detects a current including the pulse pattern and outputs it to the processing unit 13. The processing unit 13 receives control information corresponding to the pulse pattern based on the current value including the pulse pattern input from the current sensor 17.

[0061] Similarly, when transmitting control information to the processing unit 13 of the second battery pack 10b via a wire, the processing unit 33 of the vehicle control unit 32 turns on the second slot relay RYsb and turns off the first slot relay RYsa. In this state, the processing unit 33 controls the discharge switch SWd to be turned on / off according to the pulse pattern indicating the control information. As a result, a discharge current including the pulse pattern flows from the positive electrode of the second battery pack 10b to the negative electrode of the second battery pack 10b via the above-mentioned discharge path. The current sensor 17 of the second battery pack 10b detects the current including the pulse pattern and outputs it to the processing unit 13. The processing unit 13 receives the control information corresponding to the pulse pattern based on the current value including the pulse pattern input from the current sensor 17.

[0062] The processing unit 33 of the vehicle control unit 32 can receive the voltage of the power line on the battery pack 10 side (the voltage across the battery module 11) from the processing unit 13 of the battery control unit 12 using short-range wireless communication. The processing unit 33 of the vehicle control unit 32 can measure the contact resistance between the battery pack 10 and the vehicle 30 based on the received voltage on the battery pack 10 side, the voltage of the power line on the vehicle 30 side measured by the voltage sensor 34, and the current measured by the current sensor 37.

[0063] Specifically, the processing unit 33 of the vehicle control unit 32 calculates the differential voltage ΔV between the received voltage VB on the battery pack 10 side and the voltage VA of the power line on the vehicle 30 side measured by the voltage sensor 34, as shown in the following (Equation 1), and can calculate the contact resistance R between the two by dividing the calculated differential voltage ΔV by the current I.

[0064] R = (VB - VA) / I (Equation 1)

[0065] Note that the current I may be the current measured by the current sensor 17 of the battery control unit 12 received from the processing unit 13 of the battery control unit 12, instead of the current measured by the current sensor 37 of the vehicle control unit 32.

[0066] The processing unit 13 of the battery control unit 12 can receive the voltage of the power line on the vehicle 30 side from the processing unit 33 of the vehicle control unit 32 using short-range wireless communication. The processing unit 13 of the battery control unit 12 can measure the contact resistance between the battery pack 10 and the vehicle 30 based on the received voltage on the vehicle 30 side, the voltage of the power line on the battery pack 10 side measured by the voltage measurement unit 14, and the current measured by the current sensor 17.

[0067] Specifically, as shown in the above (Equation 1), the processing unit 13 of the battery control unit 12 calculates the differential voltage ΔV between the voltage VB of the power line on the battery pack 10 side measured by the voltage measurement unit 14 and the received voltage VA on the vehicle 30 side, and divides the calculated differential voltage ΔV by the current I to calculate the contact resistance R between them. Note that the current I may be a current measured by a current sensor 37 of the vehicle control unit 32 received from the processing unit 33 of the vehicle control unit 32, instead of a current measured by a current sensor 17 of the battery control unit 12.

[0068] 4, at least one of the main relay RYm, the slot relay RYs, and the power relay RYp may be replaced with a semiconductor switch, and the discharge switch SWd may be replaced with a relay.

[0069] Although not shown in Fig. 2, a configuration similar to that of the vehicle control unit 32 shown in Fig. 4 is also provided in the control unit 22 of the charging device 20. In the case of the vehicle 30, the power bus is connected to the inverter 310, but in the case of the charging device 20, the power bus is connected to the charging unit 29. Furthermore, the number of slots connected to the power bus in the charging device 20 is usually greater than that in the vehicle 30.

[0070] The processing unit 23 of the charging device 20 can exchange control signals with the processing unit 13 of the battery control unit 12 via short-range wireless communication between the wireless communication unit 26 of the charging device 20 and the wireless communication unit 16 of the battery control unit 12. In addition, the processing unit 23 of the charging device 20 can transmit control signals to the processing unit 13 of the battery control unit 12 via a wired path.

[0071] 5 is a diagram showing a basic concept of a process in which the vehicle control unit 32 authenticates the battery pack 10 mounted in the mounting slot SLa of the vehicle 30. The vehicle control unit 32 basically identifies the battery pack 10 by searching for radio waves for short-range wireless communication transmitted from the battery pack 10. Specifically, when the battery pack 10 is mounted in the mounting slot SLa, the vehicle control unit 32 transmits ID1 via a wired connection. When the battery control unit 12 of the battery pack 10 receives ID1 via a wired connection from the vehicle control unit 32, it transmits a signal including ID1 via short-range wireless communication.

[0072] When the vehicle control unit 32 receives a signal of short-range wireless communication, it compares the ID included in the received signal with the ID1 previously transmitted via a wired connection. If the two match, the vehicle control unit 32 authenticates that the battery pack 10 mounted in the mounting slot SLa and the communication partner of the short-range wireless communication are the same. If the two do not match, the vehicle control unit 32 determines that the battery pack 10 mounted in the mounting slot SLa and the communication partner of the short-range wireless communication are not the same, and does not authenticate the battery pack 10 of the communication partner. For example, when a signal including ID2 is received, it does not match the ID1 transmitted via a wired connection, so it does not authenticate the battery pack 10 to which the signal including ID2 is transmitted.

[0073] In addition, the vehicle control unit 32 may transmit an ID via short-range wireless communication, and by comparing the transmitted ID with an ID received via wired connection from the battery control unit 12 of the battery pack 10, it may be possible to determine whether the battery pack 10 mounted in the mounting slot SLa is the same as the communication partner of the short-range wireless communication.

[0074] The above explanation shows the basic concept of the process in which the vehicle control unit 32 authenticates the battery pack 10 mounted in the mounting slot SLa of the vehicle 30, but the same applies when the control unit 22 of the charging device 20 authenticates the battery pack 10 mounted in the charging slot SLc of the charging device 20.

[0075] 6 is a diagram showing a flow of assigning an ID to the replaced battery pack 10 when replacing the battery pack 10 attached to the attachment slot SLa of the vehicle 30. In state 1, the first charging slot SLc1 of the charging device 20 is an empty slot, and a charged second battery pack 10b is attached to the second charging slot SLc2. The first battery pack 10a with a low remaining capacity is attached to the first attachment slot SLa1 of the vehicle 30. The first battery pack 10a includes a vehicle ID authenticated by the vehicle control unit 32. The vehicle ID ensures that the first battery pack 10a as a physical connection partner and the first battery pack 10a as a wireless communication connection partner are identical to each other as seen from the vehicle 30 side.

[0076] In state 2, the first battery pack 10a is detached from the first mounting slot SLa1 of the vehicle 30 by a user (usually the driver of the vehicle 30), and the detached first battery pack 10a is attached to the first charging slot SLc1 of the charging device 20. If the first battery pack 10a is rented, this is a task of returning the first battery pack 10a to the charging device 20. When the first battery pack 10a is detached from the first mounting slot SLa1 of the vehicle 30, the battery control unit 12 of the first battery pack 10a deletes the vehicle ID that it holds.

[0077] In state 3, the user detaches the second battery pack 10b from the second charging slot SLc2 of the charging device 20 and attaches it to the first mounting slot SLa1 of the vehicle 30. This operation physically replaces the battery pack 10 that was attached to the first mounting slot SLa1 of the vehicle 30.

[0078] In state 4, the vehicle control unit 32 assigns a new vehicle ID to the second battery pack 10b mounted in the first mounting slot SLa1. This new vehicle ID ensures that the second battery pack 10b as a physical connection partner and the second battery pack 10b as a wireless communication connection partner are identical to each other, as viewed from the vehicle 30 side.

[0079] Fig. 7 is a sequence diagram (part 1) showing a detailed process flow when replacing the battery pack 10 mounted in the mounting slot SLa of the vehicle 30. Fig. 8 is a sequence diagram (part 2) showing a detailed process flow when replacing the battery pack 10 mounted in the mounting slot SLa of the vehicle 30. Among the horizontal lines in the sequence diagrams shown below, thin dotted lines indicate wireless communication, thin solid lines indicate wired communication, thick dotted lines indicate physical movement of the battery pack, and thick solid lines indicate charging and discharging of the battery pack.

[0080] The first charging slot SLc1 of the charging device 20 is an empty slot, and the second battery pack 10b is attached to the second charging slot SLc2. The second battery pack 10b contains a charging ID1 authenticated by the control unit 22 of the charging device 20. The charging ID1 ensures the identity of the second battery pack 10b as a physical connection partner and the second battery pack 10b as a wireless communication connection partner, as viewed from the charging device 20 side.

[0081] The charging device 20 charges the second battery pack 10b attached to the second charging slot SLc2. That is, a charging current flows from the charging unit 29 to the second battery pack 10b attached to the second charging slot SLc2. When the SOC of the second battery pack 10b reaches an upper limit, charging ends. The upper limit may be an SOC corresponding to a full charge capacity, or an SOC lower than the full charge capacity (e.g., 90%).

[0082] The first battery pack 10a is mounted in the first mounting slot SLa1 of the vehicle 30. The first battery pack 10a includes a vehicle ID authenticated by the vehicle control unit 32. The vehicle ID ensures that the first battery pack 10a as a physical connection partner and the first battery pack 10a as a wireless communication connection partner are identical to each other as seen from the vehicle 30 side. While the vehicle 30 is running, a discharge current flows from the first battery pack 10a to the motor 311 via the inverter 310. The SOC of the first battery pack 10a decreases as the vehicle 30 runs.

[0083] When a user (usually the driver of the vehicle 30) turns off the ignition, the vehicle control unit 32 accepts the ignition-off operation (P2a). When the vehicle control unit 32 accepts the ignition-off operation, it transmits a shutdown instruction to the battery control unit 12 of the first battery pack 10a by short-range wireless communication. When the battery control unit 12 of the first battery pack 10a receives the shutdown instruction from the vehicle control unit 32, it shuts down (P2b).

[0084] When the user removes the first battery pack 10a from the first mounting slot SLa1 of the vehicle 30 and mounts the first battery pack 10a in the first charging slot SLc1 of the charging device 20, the fitting detection unit 18 of the first battery pack 10a detects the fitting with the first charging slot SLc1 (P2c), and the battery control unit 12 of the first battery pack 10a starts up (P2e). The control unit 22 of the charging device 20 detects that the battery pack 10 has been mounted in the first charging slot SLc1 (P2d). Note that the battery control unit 12 of the first battery pack 10a deletes the vehicle ID when it recognizes that the battery pack 10 has been removed from the first mounting slot SLa1.

[0085] The battery control unit 12 of the first battery pack 10a becomes a beacon terminal and executes advertising for short-range wireless communication (P2f). In the example shown in Fig. 7, the advertising packet does not include a charging ID or a vehicle ID.

[0086] When the control unit 22 of the charging device 20 receives the advertisement packet, it starts a connection process with the battery control unit 12 of the first battery pack 10a (P2g). First, the control unit 22 of the charging device 20 transmits a connection request to the battery control unit 12 of the first battery pack 10a. Next, encryption parameters are exchanged between the control unit 22 of the charging device 20 and the battery control unit 12 of the first battery pack 10a. The battery control unit 12 of the first battery pack 10a generates an encryption key to be used for encrypting communication data based on the exchanged encryption parameters (P2h). The control unit 22 of the charging device 20 generates an encryption key to be used for encrypting communication data based on the exchanged encryption parameters (P2i). Finally, the generated encryption key is exchanged between the control unit 22 of the charging device 20 and the battery control unit 12 of the first battery pack 10a. As a result, a temporary connection is established between the control unit 22 of the charging device 20 and the battery control unit 12 of the first battery pack 10a.

[0087] The control unit 22 of the charging device 20 starts discharging control of the first battery pack 10a (P2j). Specifically, the control unit 22 of the charging device 20 transmits a discharge instruction to the battery control unit 12 of the first battery pack 10a by short-range wireless communication, and turns on the discharge switch SWd and the first slot relay RYsa of the charging device 20. When the battery control unit 12 of the first battery pack 10a receives the discharge instruction, it turns on the power relay RYp. As a result, a discharge path is formed between both ends of the first battery pack 10a, and a discharge current flows through the first battery pack 10a.

[0088] The control unit 22 of the charging device 20 controls the on / off of the discharge switch SWd according to the discharge pattern corresponding to the charge ID2. The battery control unit 12 of the first battery pack 10a reads the discharge pattern from the current value detected by the current sensor 17 to obtain the charge ID2. A communication pulse generated by such control of the discharge current is communicated between the control unit 22 of the charging device 20 and the battery control unit 12 of the first battery pack 10a, and the charge ID2 is written from the control unit 22 of the charging device 20 to the battery control unit 12 of the first battery pack 10a (P2k). The battery control unit 12 of the first battery pack 10a transmits the discharge pattern corresponding to the read charge ID2 to the control unit 22 of the charging device 20 by short-range wireless communication.

[0089] During the period when a discharge current including a discharge pattern according to charge ID2 is flowing, the control unit 22 of the charging device 20 measures the voltage of the power line on the charging device 20 side using a voltage sensor of the charging device 20, and measures the current flowing in the discharge path using a current sensor of the charging device 20 (P2l). During the period when a discharge current including a discharge pattern according to charge ID2 is flowing, the battery control unit 12 of the first battery pack 10a measures the voltage of the power line on the first battery pack 10a side using the voltage measurement unit 14 (P2m).

[0090] When the control unit 22 of the charging device 20 receives a signal including a discharge pattern from the battery control unit 12 of the first battery pack 10a, the control unit 22 compares the charge ID indicated by the received discharge pattern with the charge ID previously transmitted via wire (P2m). In the example shown in Fig. 7, if the charge ID indicated by the discharge pattern included in the received signal is charge ID2, the comparison is successful, and if it is not charge ID2, the comparison is unsuccessful.

[0091] The control unit 22 of the charging device 20 transmits the result of the comparison to the battery control unit 12 of the first battery pack 10a by short-range wireless communication. If the comparison fails, the control unit 22 of the charging device 20 cuts off the temporary connection with the battery control unit 12 of the first battery pack 10a, and resumes scanning for advertising packets after a predetermined time has elapsed. The battery control unit 12 of the first battery pack 10a cuts off the temporary connection with the control unit 22 of the charging device 20, and resumes advertising via short-range wireless communication. If the comparison is successful, pairing between the control unit 22 of the charging device 20 and the battery control unit 12 of the first battery pack 10a is completed (P2o, P2p). With the completion of pairing between the two, the process of returning the first battery pack 10a to the charging device 20 is completed.

[0092] When pairing is completed, the battery control unit 12 of the first battery pack 10a transmits the measured voltage of the power line on the first battery pack 10a side to the control unit 22 of the charging device 20 by short-range wireless communication. The control unit 22 of the charging device 20 measures the contact resistance between the charging device 20 and the first battery pack 10a based on the received voltage of the power line on the first battery pack 10a side, the measured voltage of the power line on the charging device 20 side, and the measured current of the discharge path (P2q). At this time, it is desirable for the control unit 22 of the charging device 20 to adopt the value in the state where the measured contact resistance value has converged as the official value of the contact resistance. Since the discharge current from the first battery pack 10a is a communication pulse that forms a discharge pattern according to identification information such as charging ID1 and ID2, if the pulse width is short, the communication pulse does not rise completely, and the measurement is based on the value in the middle of the rise of the pulse current, and the measured contact resistance is unreliable. In response to this, for example, the control unit 22 of the charging device 20 uses a communication pulse signal in which a communication pulse for resistance measurement, which has a width longer than that of the communication pulse for identification information, is added to the communication pulse for identification information that forms a current pattern corresponding to the identification information, and measures the contact resistance from the communication pulse for resistance measurement. The width of the communication pulse for identification information is set to, for example, 1 μsec to 0.1 ms, and in this case, the width of the communication pulse for resistance measurement is set to, for example, a value longer than 1 μsec to 0.1 ms and shorter than 10 ms. This makes it possible to minimize the extension of the period during which the discharge current including the discharge pattern corresponding to the identification information flows, and reliably measure the contact resistance in an appropriate measurement period. In addition, the control unit 22 of the charging device 20 may continue measuring the contact resistance until the measured contact resistance value becomes stable, or may measure the contact resistance using a contact resistance value in a converged state estimated based on the current change from the start of discharge. These allow the contact resistance to be measured with high reliability.

[0093] The control unit 22 of the charging device 20 compares the measured contact resistance with a threshold value previously set by a designer (P2r). If the measured contact resistance exceeds the threshold value, the control unit 22 of the charging device 20 controls the discharge switch SWd and the first slot relay RYsa to the OFF state. The control unit 22 of the charging device 20 also transmits an alert signal to a terminal device (not shown) of an administrator of the charging device 20. When the administrator of the charging device 20 receives the alert signal at the terminal device, the administrator goes to the installation site of the charging device 20. The administrator uses an inspection device (not shown) to check the terminal portion of the first charging slot SLc1 and the terminal portion of the first battery pack 10a to identify the cause of the increase in contact resistance.

[0094] If the cause lies in the terminal portion of the first charging slot SLc1, the terminal portion of the first charging slot SLc1 is serviced, repaired or replaced, or the entire first charging slot SLc1 is replaced. Alternatively, the first charging slot SLc1 is made unusable. If the cause lies in the terminal portion of the first battery pack 10a, the terminal portion of the first battery pack 10a is serviced, repaired or replaced, or the first battery pack 10a is discarded. Note that in the case of a temporary contact failure, the contact failure may be resolved by removing the first battery pack 10a and then reattaching it. If the measured contact resistance does not exceed the threshold, no alert signal is sent to the administrator's terminal device.

[0095] The control unit 22 of the charging device 20 selects another battery pack 10 to be used to replace the first battery pack 10a (P2s). Specifically, the control unit 22 of the charging device 20 selects one of the charged battery packs 10 attached to the multiple charging slots SLc of the charging stand 21. In the example shown in Fig. 8, the control unit 22 selects the charged second battery pack 10b attached to the second charging slot SLc2.

[0096] The control unit 22 of the charging device 20 transmits a shutdown instruction to the battery control unit 12 of the selected second battery pack 10b via short-range wireless communication, and executes a process of disconnecting the battery control unit 12 of the second battery pack 10b (P2t). Upon receiving the shutdown instruction from the control unit 22 of the charging device 20, the battery control unit 12 of the second battery pack 10b shuts down (P2u). Just before shutting down, the battery control unit 12 of the second battery pack 10b transmits a shutdown completion notification to the control unit 22 of the charging device 20.

[0097] When the control unit 22 of the charging device 20 receives the shutdown completion notification from the battery control unit 12 of the second battery pack 10b, it instructs the user of the vehicle 30 to remove the second battery pack 10b attached to the second charging slot SLc2 (P2v). For example, the control unit 22 of the charging device 20 causes the display unit 27 to display a message instructing the user to remove the second battery pack 10b attached to the second charging slot SLc2. At this time, the control unit 22 of the charging device 20 may output audio guidance to the user from a speaker (not shown). Also, only the lamp (not shown) of the second charging slot SLc2 may be turned on or flashed. Also, only the lamp (not shown) of the second charging slot SLc2 may be turned on in a color different from the lamps of the other charging slots.

[0098] When the user removes the second battery pack 10b from the second charging slot SLc2 and installs the second battery pack 10b in the first mounting slot SLa1 of the vehicle 30, the fitting detection unit 18 of the second battery pack 10b detects the fitting with the first mounting slot SLa1 (P2x), and the battery control unit 12 of the second battery pack 10b starts up (P2z). When the fitting detection unit 38 of the vehicle 30 detects that the battery pack 10 has been installed in the first mounting slot SLa1 (P2y), the vehicle control unit 32 starts up (P2A). Note that the battery control unit 12 of the second battery pack 10b deletes the charging ID2 when it recognizes that the battery pack 10 has been removed from the second charging slot SLc2.

[0099] The control unit 22 of the charging device 20 starts charging control of the first battery pack 10a attached to the first charging slot SLc1 (P2w). Specifically, the control unit 22 of the charging device 20 transmits a charging instruction to the battery control unit 12 of the first battery pack 10a by short-range wireless communication, and turns on the second slot relay RYsb. When the battery control unit 12 of the first battery pack 10a receives the charging instruction, it turns on the power relay RYp. As a result, a charging current flows from the charging unit 29 of the charging device 20 to the first battery pack 10a attached to the first charging slot SLc1.

[0100] The battery control unit 12 of the second battery pack 10b acts as a beacon terminal and performs advertising in short-range wireless communication (P2B). In the example shown in Fig. 8, the advertising packet does not include a charging ID or a vehicle ID.

[0101] When the vehicle control unit 32 receives the advertisement packet, it starts a process of connection with the battery control unit 12 of the second battery pack 10b (P2C). First, the vehicle control unit 32 transmits a connection request to the battery control unit 12 of the second battery pack 10b. Next, encryption parameters are exchanged between the vehicle control unit 32 and the battery control unit 12 of the second battery pack 10b. The battery control unit 12 of the second battery pack 10b generates an encryption key to be used for encrypting communication data based on the exchanged encryption parameters (P2D). The vehicle control unit 32 generates an encryption key to be used for encrypting communication data based on the exchanged encryption parameters (P2E). Finally, the generated encryption key is exchanged between the vehicle control unit 32 and the battery control unit 12 of the second battery pack 10b. This makes a temporary connection between the vehicle control unit 32 and the battery control unit 12 of the second battery pack 10b.

[0102] The vehicle control unit 32 starts discharging control of the second battery pack 10b (P2F). Specifically, the vehicle control unit 32 transmits a discharge command to the battery control unit 12 of the second battery pack 10b by short-range wireless communication, and turns on the discharge switch SWd and the second slot relay RYsb. When the battery control unit 12 of the second battery pack 10b receives the discharge command, it turns on the power relay RYp. This forms a discharge path between both ends of the second battery pack 10b, and a discharge current flows through the second battery pack 10b.

[0103] The vehicle control unit 32 controls the on / off of the discharge switch SWd according to the discharge pattern corresponding to the vehicle ID. The battery control unit 12 of the second battery pack 10b reads the discharge pattern from the current value detected by the current sensor 17 to obtain the vehicle ID. By controlling the discharge current in this way, the vehicle ID is written from the vehicle control unit 32 to the battery control unit 12 of the second battery pack 10b (P2G). The battery control unit 12 of the second battery pack 10b transmits the discharge pattern corresponding to the read vehicle ID to the vehicle control unit 32 by short-range wireless communication. The communication pulse signal forming the discharge pattern transmitted to the vehicle control unit 32 is generated by adding a resistance measurement communication pulse having a width longer than the width of the identification information communication pulse to an identification information communication pulse forming a current pattern corresponding to the identification information, similar to the communication pulse used between the control unit 22 of the charging device 20 and the battery control unit 12 of the battery pack 10.

[0104] During the period when a discharge current including a discharge pattern according to the vehicle ID is flowing, the vehicle control unit 32 measures the voltage of the power line on the vehicle 30 side with the voltage sensor 34, and measures the current flowing in the discharge path with the current sensor 37 (P2I). During the period when a discharge current including a discharge pattern according to the vehicle ID is flowing, the battery control unit 12 of the second battery pack 10b measures the voltage of the power line on the second battery pack 10b side with the voltage measurement unit 14 (P2H).

[0105] When the vehicle control unit 32 receives a signal including a discharge pattern from the battery control unit 12 of the second battery pack 10b, it compares the vehicle ID indicated by the received discharge pattern with the vehicle ID previously transmitted via wire (P2J). The vehicle control unit 32 transmits the comparison result to the battery control unit 12 of the second battery pack 10b by short-range wireless communication. If the comparison fails, the vehicle control unit 32 disconnects the temporary connection with the battery control unit 12 of the second battery pack 10b, and resumes scanning the advertising packet after a predetermined time has elapsed. The battery control unit 12 of the second battery pack 10b disconnects the temporary connection with the vehicle control unit 32, and resumes advertising by short-range wireless communication. If the comparison is successful, pairing between the vehicle control unit 32 and the battery control unit 12 of the second battery pack 10b is completed (P2K, P2L).

[0106] When pairing is complete, the battery control unit 12 of the second battery pack 10b transmits the measured power line voltage on the second battery pack 10b side to the vehicle control unit 32 by short-range wireless communication. The control unit 22 of the charging device 20 measures the contact resistance between the vehicle 30 and the second battery pack 10b based on the received power line voltage on the second battery pack 10b side, the measured power line voltage on the vehicle 30 side, and the measured current of the discharge path (P2M). At this time, it is preferable that the vehicle control unit 32 adopts the value at which the measured contact resistance has converged as the official contact resistance value.

[0107] The vehicle control unit 32 compares the measured contact resistance with a threshold value previously set by the designer (P2N). If the measured contact resistance exceeds the threshold value, the vehicle control unit 32 controls the discharge switch SWd and the first slot relay RYsa to the off state. The vehicle control unit 32 also displays warning information indicating that the second battery pack 10b is not installed properly on the meter panel 39. If a speaker (not shown) is installed in the vehicle 30, the vehicle control unit 32 may output the warning information indicating that the second battery pack 10b is not installed properly as sound from the speaker.

[0108] When the measured contact resistance exceeds a threshold, the vehicle control unit 32 may notify a warning message including a countermeasure by at least one of text and voice. In this case, the vehicle control unit 32 may notify a different countermeasure depending on the degree of deviation between the measured contact resistance and the threshold. For example, when the degree of deviation is smaller than a set value, the vehicle control unit 32 may notify a message urging the user to remove the second battery pack 10b and reattach the second battery pack 10b. When the degree of deviation is larger than the set value, the vehicle control unit 32 may notify a message urging the user to remove the second battery pack 10b and replace it with another battery pack 10.

[0109] If the poor installation condition is not resolved even when the user replaces the battery pack 10 with another battery pack 10, it is presumed that the cause of the poor contact is the terminal part of the first installation slot SLa1 of the vehicle 30, and the vehicle control unit 32 may issue a message urging inspection and repair of the first installation slot SLa1 of the vehicle 30.

[0110] If the measured contact resistance exceeds a threshold, the vehicle control unit 32 may connect to the charging device 20 via short-range wireless communication and cause at least one of the display unit 27 and the speaker (not shown) of the charging device 20 to notify a warning message indicating that the second battery pack 10b is not properly installed. If the measured contact resistance exceeds a threshold, the vehicle control unit 32 may connect to a smartphone carried by the user via short-range wireless communication and cause at least one of the display (not shown) and the speaker (not shown) of the charging device 20 to notify a warning message indicating that the second battery pack 10b is not properly installed. If the measured contact resistance does not exceed the threshold, the warning message is not notified.

[0111] After completing pairing between the vehicle control unit 32 and the battery control unit 12 of the second battery pack 10b, the vehicle control unit 32 transmits a shutdown instruction to the battery control unit 12 of the second battery pack 10b by short-range wireless communication. Upon receiving the shutdown instruction from the vehicle control unit 32, the battery control unit 12 of the second battery pack 10b shuts down (P2O).

[0112] Fig. 9 is a sequence diagram (part 1) showing a process flow according to a modified example of the process shown in Fig. 7. Fig. 10 is a sequence diagram (part 2) showing a process flow according to a modified example of the process shown in Fig. 8. Below, differences from the processes shown in Figs. 7 and 8 will be described.

[0113] In the modified example, during a period in which a discharge current including a discharge pattern according to charge ID2 is flowing, the control unit 22 of the charging device 20 measures the voltage of the power line on the charging device 20 side using the voltage sensor of the charging device 20 (P2m'). During a period in which a discharge current including a discharge pattern according to charge ID2 is flowing, the battery control unit 12 of the first battery pack 10a measures the voltage of the power line on the first battery pack 10a side using the voltage measurement unit 14, and measures the current flowing in the discharge path using the current sensor 17 (P2l').

[0114] In the modified example, when pairing between the control unit 22 of the charging device 20 and the battery control unit 12 of the first battery pack 10a is completed, the control unit 22 of the charging device 20 transmits the measured power line voltage of the charging device 20 to the battery control unit 12 of the first battery pack 10a by short-range wireless communication. The battery control unit 12 of the first battery pack 10a measures the contact resistance between the charging device 20 and the first battery pack 10a based on the received power line voltage of the charging device 20 side, the measured power line voltage of the first battery pack 10a side, and the measured current of the discharge path (P2q'). At this time, it is preferable that the battery control unit 12 of the first battery pack 10a adopts the value at which the measured contact resistance value has converged as the official contact resistance value.

[0115] The battery control unit 12 of the first battery pack 10a compares the measured contact resistance with a threshold value previously set by a designer (P2r'). If the measured contact resistance exceeds the threshold value, the battery control unit 12 of the first battery pack 10a controls the power relay RYp to the off state. The battery control unit 12 of the first battery pack 10a transmits an alert signal indicating poor contact between the first battery pack 10a and the charging device 20 to the control unit 22 of the charging device 20 by short-range wireless communication. When the control unit 22 of the charging device 20 receives the alert signal, it transmits the alert signal to a terminal device (not shown) of the administrator of the charging device 20.

[0116] In the modified example, during a period in which a discharge current including a discharge pattern according to the vehicle ID is flowing, the vehicle control unit 32 measures the voltage of the power line on the vehicle 30 side using the voltage sensor 34 (P2H'). During a period in which a discharge current including a discharge pattern according to the vehicle ID is flowing, the battery control unit 12 of the second battery pack 10b measures the voltage of the power line on the second battery pack 10b side using the voltage measurement unit 14, and measures the current flowing in the discharge path using the current sensor 17 (P2I').

[0117] In the modified example, when pairing between the vehicle control unit 32 and the battery control unit 12 of the second battery pack 10b is completed, the vehicle control unit 32 transmits the measured voltage of the power line on the vehicle 30 side to the battery control unit 12 of the second battery pack 10b by short-range wireless communication. The battery control unit 12 of the second battery pack 10b measures the contact resistance between the vehicle 30 and the second battery pack 10b based on the received voltage of the power line on the vehicle 30 side, the measured voltage of the power line on the second battery pack 10b side, and the measured current of the discharge path (P2M'). At this time, it is preferable that the vehicle control unit 32 adopts the value at which the measured contact resistance value has converged as the official contact resistance value.

[0118] The battery control unit 12 of the second battery pack 10b compares the measured contact resistance with a threshold value previously set by a designer (P2N'). If the measured contact resistance exceeds the threshold value, the battery control unit 12 of the second battery pack 10b controls the power relay RYp to the off state. The battery control unit 12 of the second battery pack 10b also transmits an alert signal indicating poor contact between the second battery pack 10b and the vehicle 30 to the vehicle control unit 32 by short-range wireless communication. Upon receiving the alert signal, the vehicle control unit 32 displays warning information indicating improper installation of the second battery pack 10b on the meter panel 39. If a speaker (not shown) is installed in the vehicle 30, the vehicle control unit 32 may output the warning information indicating improper installation of the second battery pack 10b by voice from the speaker.

[0119] As described above, in this embodiment, an ID is written to the battery pack 10 from the vehicle 30 or the charging device 20 via a wired connection, and the ID is looped back from the battery pack 10 to the vehicle 30 or the charging device 20 by short-range wireless communication. This allows the vehicle 30 or the charging device 20, which controls the battery pack 10 using short-range wireless communication, to correctly identify the attached battery pack 10. This eliminates malfunctions such as the vehicle control unit 32 of a certain vehicle 30 erroneously controlling the battery pack 10 attached to another nearby vehicle 30, and ensures safety and security of the entire vehicle system 1 using the charging device 20 and the replaceable battery pack 10. A user can safely drive the vehicle 30 by simply removing the battery pack 10 attached to the charging device 20 and attaching it to the vehicle 30.

[0120] By transmitting and receiving control signals between the vehicle 30 or the charging device 20 and the battery pack 10 via short-range wireless communication, it is possible to reduce the number of pins included in the connector of the battery pack 10. This makes it possible to reduce mechanical connection failures between the vehicle 30 or the charging device 20 and the battery pack 10. In addition, firmware used in the battery control unit 12 of the battery pack 10 can be updated via wireless communication, making it easier to update the firmware.

[0121] In this embodiment, in the authentication process using the current pattern flowing through the power line, the contact resistance is measured based on the differential voltage between the battery pack 10 and the vehicle 30 or the charging device 20, and the current flowing through the power line. This makes it possible to complete the abnormality determination of the contact resistance within the authentication process.

[0122] Usually, the contact resistance is measured in the charge / discharge process following the authentication process. In contrast, in this embodiment, the contact resistance is measured during the authentication process. As a result, if the contact resistance is normal, charging / discharging can be started more quickly. If the contact resistance is abnormal, the user can be notified of poor contact in the battery pack 10 more quickly. In the case of minor poor contact, the poor contact can be resolved by encouraging the user to reattach the battery pack. In the case of major poor contact, the current is cut off, thereby preventing the occurrence of unsafe events due to heat generation accompanying charging / discharging.

[0123] In this way, by measuring the contact resistance during the authentication process, the number of steps in the authentication process and the charging / discharging process as a whole can be reduced, and the authentication process and the charging / discharging process as a whole can be shortened. Furthermore, if the user manually moves the vehicle 30 from in front of the charging device 20 during the period between the authentication process and the charging / discharging process, the method of measuring the contact resistance during the charging / discharging process does not allow the battery pack 10 to be immediately replaced with another battery pack 10 even if a poor contact is detected. In contrast, in this embodiment, the contact resistance is measured during the authentication process, so the user can know whether or not there is a poor contact at the same time as installing the battery pack 10. This improves user convenience.

[0124] The present disclosure has been described above based on the embodiments. The embodiments are merely examples, and it will be understood by those skilled in the art that various modifications are possible in the combination of each component and each processing step, and that such modifications are also within the scope of the present disclosure.

[0125] For example, before a discharge current is passed, an offset error between the voltage measurement unit 14 of the battery pack 10 and the voltage sensor of the charging device 20 or the voltage sensor 34 of the vehicle 30 may be measured. The offset error may be calculated on the battery control unit 12 side, or may be measured on the control unit 22 of the charging device 20 or the vehicle control unit 32 side. When calculating the contact resistance, the battery control unit 12, the control unit 22 of the charging device 20, or the vehicle control unit 32 corrects the differential voltage ΔV=(VB-VA) in the above (Equation 1) with the offset error. This makes it possible to improve the measurement accuracy of the contact resistance.

[0126] In the above-described embodiment, an example has been described in which the battery pack 10 incorporating the battery module 11 including lithium ion battery cells, nickel metal hydride battery cells, lead battery cells, etc. is used. In this regard, a capacitor pack incorporating a capacitor module including electric double layer capacitor cells, lithium ion capacitor cells, etc. may also be used. In this specification, the battery pack and the capacitor pack are collectively referred to as a power storage pack.

[0127] In the above embodiment, an electric motorcycle (electric scooter) is assumed as the vehicle 30 powered by the replaceable battery pack 10. In this regard, the vehicle 30 may be an electric bicycle. The vehicle 30 may also be a four-wheeled electric vehicle (EV). Electric vehicles include not only full-standard electric vehicles, but also low-speed electric vehicles such as golf carts and land cars used in shopping malls, entertainment facilities, etc.

[0128] The electric vehicle using the replaceable battery pack 10 as a power source is not limited to the vehicle 30. For example, the electric vehicle also includes an electric ship. For example, the power source of a water bus or a water taxi may be the replaceable battery pack 10. The electric vehicle also includes a train. For example, a train equipped with the replaceable battery pack 10 can be used instead of a diesel railcar used on a non-electrified line. The electric vehicle also includes an electric flying object. The electric flying object includes a multicopters (drones). The multicopters also include so-called flying cars. In any electric vehicle, the time required for energy refueling can be shortened.

[0129] The embodiment may be specified by the following items.

[0130] [Item 1] A power storage unit (11) for supplying power to an electric vehicle (30); a control unit (32) of the electric vehicle (30) and a control unit (12) that performs communication for authentication based on a pattern of a current flowing through a power line when the electricity storage pack (10) is attached to the electric vehicle (30), A control unit (12) of the electricity storage pack (10) measures the contact resistance between the electricity storage pack (10) and the electric vehicle (30) based on the voltage of the power line on the electricity storage pack (10) side, the voltage of the power line on the electric vehicle (30) side received from a control unit (32) of the electric vehicle (30), and a current when performing authentication communication based on a pattern of a current flowing through the power line. An electricity storage pack (10). This makes it possible to efficiently measure the contact resistance when the electricity storage pack (10) is attached. [Item 2] generating a communication signal to be communicated between a control unit (12) of the electricity storage pack (10) and a control unit (32) of the electric vehicle (30) when performing the authentication communication as a pulse signal based on a pattern of a current flowing through the power line; the pulse signal includes an identification information communication pulse having a current pattern corresponding to the identification information for authentication, and a resistance measurement communication pulse having a width longer than that of the identification information communication pulse, The resistance measurement communication S The contact resistance is measured by 6. The electricity storage pack (10) according to item 5. This makes it possible to improve the measurement accuracy of the contact resistance. [Item 3] The control unit (12) of the electricity storage pack (10) When the electricity storage pack (10) is attached to the electric vehicle (30), it transmits a signal to notify the presence of the electricity storage pack (10) via short-range wireless communication, receiving identification information transmitted from the control unit (32) of the electric vehicle (30) based on a pattern of a current flowing through the power line after being temporarily connected to the control unit (32) of the electric vehicle (30); When the identification information is received from the control unit (32) of the electric vehicle (30), a signal including the identification information is transmitted to the control unit (32) of the electric vehicle (30) via the short-range wireless communication; the signal transmitted by the short-range wireless communication is used in a control unit (32) of the electric vehicle (30) to authenticate whether the electricity storage pack (10) attached to the electric vehicle (30) and a communication partner of the short-range wireless communication are the same; The control unit (12) of the electricity storage pack (10) Using the current pattern flowing through the power line measuring the contact resistance during an authentication process; 3. The electricity storage pack (10) according to item 1 or 2. This enables the control unit (32) of the electric vehicle (30) to accurately authenticate whether the attached electricity storage pack (10) and the communication partner of the short-range wireless communication are the same. [Item 4] When the measured contact resistance exceeds a threshold value, the control unit (12) of the electricity storage pack (10) transmits an alert signal to the control unit (32) of the electric vehicle (30). The electricity storage pack (10) according to any one of items 1 to 3. This allows the control unit (32) of the electric vehicle (30) to recognize the contact failure. [Item 5] A power storage unit (11) for supplying power to an electric vehicle (30); a control unit (12) that performs authentication communication with a control unit (22) of a charging device (20) based on a pattern of a current flowing through a power line when the electricity storage pack (10) is attached to a charging slot (SLc1) of the charging device (20), a control unit (12) of the electricity storage pack (10) measures contact resistance between the electricity storage pack (10) and the charging device (20) based on a voltage of the power line on the electricity storage pack (10) side, a voltage of the power line on the charging device (20) side received from a control unit (22) of the charging device (20), and a current when performing authentication communication based on a pattern of a current flowing through the power line. An electricity storage pack (10). This makes it possible to efficiently measure the contact resistance when the electricity storage pack (10) is attached. [Item 6] generating a communication signal to be communicated between a control unit (12) of the electricity storage pack (10) and a control unit (22) of the charging device (20) when performing the authentication communication as a pulse signal based on a pattern of a current flowing through the power line; the pulse signal includes an identification information communication pulse having a current pattern corresponding to the identification information for authentication, and a resistance measurement communication pulse having a width longer than that of the identification information communication pulse, The resistance measurement communication S The contact resistance is measured by 6. The electricity storage pack (10) according to item 5. This makes it possible to improve the measurement accuracy of the contact resistance. [Item 7] The control unit (12) of the electricity storage pack (10) When the electricity storage pack (10) is inserted into the charging slot (SLc1) of the charging device (20), the electricity storage pack (10) transmits a signal to notify the presence of the electricity storage pack (10) by short-range wireless communication, receiving identification information transmitted from the control unit (22) of the charging device (20) based on a pattern of a current flowing through the power line after being temporarily connected to the control unit (22) of the charging device (20); When the identification information is received from the control unit (22) of the charging device (20), a signal including the identification information is transmitted to the control unit (22) of the charging device (20) via the short-range wireless communication; the signal transmitted by the short-range wireless communication is used in a control unit (22) of the charging device (20) to authenticate whether the electricity storage pack (10) attached to the charging slot (SLc1) of the charging device (20) and a communication partner of the short-range wireless communication are the same as each other; The control unit (12) of the electricity storage pack (10) Using the current pattern flowing through the power line measuring the contact resistance during an authentication process; 7. The electricity storage pack (10) according to item 5 or 6. This enables the control unit (22) of the charging device (20) to accurately authenticate whether the electricity storage pack (10) attached to the charging slot (SLc1) and the communication partner of the short-range wireless communication are the same. [Item 8] When the measured contact resistance value exceeds a threshold value, the control unit (12) of the electricity storage pack (10) transmits an alert signal to the control unit (22) of the charging device (20). The electricity storage pack (10) according to any one of items 5 to 7. This allows the control unit (22) of the charging device (20) to recognize the contact failure. [Item 9] The electricity storage pack (10) according to any one of items 1 to 8, wherein the control unit (12) of the electricity storage pack (10) defines a value at which the measured contact resistance has converged as an official contact resistance value. This makes it possible to improve the measurement accuracy of the contact resistance. [Item 10] A motor (311); a control unit (32) that performs authentication communication with a control unit (12) of the power storage pack (10) for supplying power to the motor (311) in a state where the power storage pack (10) is attached to the electric vehicle (30), using a pattern of a current flowing through a power line; A control unit (32) of the electric vehicle (30) measures the contact resistance between the electric vehicle (30) and the power storage pack (10) based on the voltage of the power line on the electric vehicle (30) side, the voltage of the power line on the power storage pack (10) side received from the control unit (12) of the power storage pack (10), and the current when performing authentication communication based on the pattern of the current flowing through the power line. An electric vehicle (30). This makes it possible to efficiently measure the contact resistance when the electricity storage pack (10) is attached. [Item 11] The control unit (32) of the electric vehicle (30) After the power storage pack (10) is attached to the electric vehicle (30), when a signal transmitted by short-range wireless communication is received, a temporary connection is established with the control unit of the transmission destination of the signal, transmitting identification information to a control unit (12) of the power storage pack (10) mounted on the electric vehicle (30) based on a pattern of current flowing through the power line; When a signal transmitted by the short-range wireless communication from the control unit (12) of the temporarily connected electricity storage pack (10) is received, the identification information included in the received signal is compared to the transmitted identification information based on the pattern of the current flowing through the power line to see if it matches, and when they match, the power storage pack (10) attached to the electric vehicle (30) is authenticated as being the same as the communication partner of the short-range wireless communication; Using the current pattern flowing through the power line measuring the contact resistance during an authentication process; 11. The electric vehicle (30) according to item 10. This enables the control unit (32) of the electric vehicle (30) to accurately authenticate whether the attached electricity storage pack (10) and the communication partner of the short-range wireless communication are the same. [Item 12] The electric vehicle further includes an alarm unit (39) for notifying information indicating a state of the electric vehicle (30), a control unit (32) of the electric vehicle (30) causes the notification unit (39) to notify information indicating improper installation of the electricity storage pack (10) when the measured contact resistance exceeds a threshold value; 12. The electric vehicle (30) according to claim 10 or 11. This allows the user to be made aware of the contact failure. [Item 13] The control unit (32) of the electric vehicle (30) is configured to regard the value at which the measured contact resistance has converged as the official contact resistance value. This makes it possible to improve the measurement accuracy of the contact resistance. [Item 14] Charging slot (SLc1) and a control unit (22) that performs authentication communication with a control unit (12) of the electricity storage pack (10) based on a pattern of a current flowing through a power line when the electricity storage pack (10) is attached to the charging slot (SLc1), a control unit (22) of the charging device (20) measures contact resistance between the charging device (20) and the electricity storage pack (10) based on a voltage of the power line on the charging device (20) side, a voltage of the power line on the electricity storage pack (10) side received from the control unit (12) of the electricity storage pack (10), and a current when performing authentication communication based on a current pattern flowing through the power line; A charging device (20). This makes it possible to efficiently measure the contact resistance when the electricity storage pack (10) is attached. [Item 15] The control unit (22) of the charging device (20) When the power storage pack (10) is attached to the charging slot (SLc1) and a signal transmitted by short-range wireless communication is received, a temporary connection is made to a control unit that is a destination of the signal, transmitting identification information to a control unit (12) of the electricity storage pack (10) attached to the charging slot (SLc1) based on a pattern of a current flowing through the power line; When a signal transmitted by the short-range wireless communication from the control unit (12) of the temporarily connected electricity storage pack (10) is received, a comparison is made to see whether or not identification information included in the received signal matches the identification information transmitted based on the pattern of the current flowing through the power line, and when they match, authentication is made that the electricity storage pack (10) attached to the charging slot (SLc1) and the communication partner of the short-range wireless communication are the same; Using the current pattern flowing through the power line measuring the contact resistance during an authentication process; 15. The charging device (20) according to item 14, characterized in that This enables the control unit (22) of the charging device (20) to accurately authenticate whether the electricity storage pack (10) attached to the charging slot (SLc1) and the communication partner of the short-range wireless communication are the same. [Item 16] When the measured contact resistance exceeds a threshold value, the control unit (22) of the charging device (20) transmits an alert signal to a terminal device of an administrator of the charging device (20). 16. A charging device (20) according to claim 14 or 15. This allows the manager of the charging device (20) to become aware of the poor contact. [Item 17] The charging device (20) according to any one of items 14 to 16, wherein the control unit (22) of the charging device (20) sets a value at which the measured contact resistance has converged as an official value of the contact resistance. This makes it possible to improve the measurement accuracy of the contact resistance. [Explanation of symbols]

[0131] 1 vehicle system, 2 commercial power system, 10 battery pack, 11 battery module, E1-En cell, 12 battery control unit, 13 processing unit, 14 voltage measurement unit, 15 antenna, 16 wireless communication unit, 17 current sensor, 18 mating detection unit, 20 charging device, 21 charging stand, SLc charging slot, 22 control unit, 23 processing unit, 25 antenna, 26 wireless communication unit, 27 display unit, 28 operation unit, 29 charging unit, 30 vehicle, 31 battery mounting unit, SLa mounting slot, 32 vehicle control unit, 33 processing unit, 33r relay control unit, 34 voltage sensor, 35 antenna, 36 wireless communication unit, 37 current sensor, 38a first mating detection unit, 38b second mating detection unit, 38p Pack detection unit, 39 meter panel, 310 inverter, 311 motor, 312 tire, RYm main relay, RYs slot relay, RYp power relay, SWd discharge switch, F1 fuse, R1 resistor, Tp positive terminal, Tm negative terminal.

Claims

1. A power storage unit for supplying power to an electrically-driven moving object; a control unit of the electric vehicle and a control unit that performs communication for authentication based on a pattern of a current flowing through a power line when the power storage pack is attached to the electric vehicle; a control unit of the power storage pack measures contact resistance between the power storage pack and the electric vehicle based on a voltage of the power line on the power storage pack side, a voltage of the power line on the electric vehicle side received from a control unit of the electric vehicle, and a current when performing authentication communication based on a pattern of a current flowing through the power line. The power storage pack is characterized by:

2. generating a communication signal to be communicated between a control unit of the power storage pack and a control unit of the electric vehicle when performing the authentication communication, as a pulse signal based on a pattern of a current flowing through the power line; the pulse signal includes an identification information communication pulse having a current pattern corresponding to the identification information for authentication, and a resistance measurement communication pulse having a width longer than that of the identification information communication pulse, The contact resistance is measured by the resistance measurement communication pulse. The electricity storage pack according to claim 1 .

3. The control unit of the power storage pack includes: When the electricity storage pack is attached to the electric vehicle, the electricity storage pack transmits a signal to notify the electric vehicle of its presence via short-range wireless communication; After being temporarily connected to the control unit of the electric vehicle, receiving identification information transmitted from the control unit of the electric vehicle based on a pattern of a current flowing through the power line; When the identification information is received from the control unit of the electric vehicle, a signal including the identification information is transmitted to the control unit of the electric vehicle by the short-range wireless communication; the signal transmitted by the short-range wireless communication is used in a control unit of the electric vehicle to authenticate whether or not the power storage pack attached to the electric vehicle and a communication partner of the short-range wireless communication are the same; The control unit of the electricity storage pack measures the contact resistance during an authentication process that utilizes a current pattern flowing through the power line.

3. The electricity storage pack according to claim 1 or 2.

4. When the measured contact resistance exceeds a threshold value, the control unit of the electricity storage pack transmits an alert signal to the control unit of the electric vehicle. The electricity storage pack according to claim 1 .

5. A power storage unit for supplying power to an electrically-driven moving object; a control unit that performs authentication communication with a control unit of the charging device based on a pattern of a current flowing through a power line when the power storage pack is attached to a charging slot of the charging device, a control unit of the electricity storage pack measures a contact resistance between the electricity storage pack and the charging device based on a voltage of the power line on the electricity storage pack side, a voltage of the power line on the charging device side received from the control unit of the charging device, and a current when performing authentication communication based on a pattern of a current flowing through the power line. The power storage pack is characterized by:

6. generating a communication signal to be communicated between a control unit of the power storage pack and a control unit of the charging device when performing the authentication communication, as a pulse signal based on a pattern of a current flowing through the power line; the pulse signal includes an identification information communication pulse having a current pattern corresponding to the identification information for authentication, and a resistance measurement communication pulse having a width longer than that of the identification information communication pulse, The contact resistance is measured by the resistance measurement communication pulse. The electricity storage pack according to claim 5 .

7. The control unit of the power storage pack includes: When the electricity storage pack is inserted into the charging slot of the charging device, the electricity storage pack transmits a signal to notify the presence of the electricity storage pack via short-range wireless communication; After being temporarily connected to the control unit of the charging device, receiving identification information transmitted from the control unit of the charging device based on a pattern of a current flowing through the power line; When the identification information is received from the control unit of the charging device, a signal including the identification information is transmitted to the control unit of the charging device via the short-range wireless communication; the signal transmitted by the short-range wireless communication is used in a control unit of the charging device to authenticate whether or not the electricity storage pack attached to the charging slot of the charging device and a communication partner of the short-range wireless communication are the same; The control unit of the electricity storage pack measures the contact resistance during an authentication process that utilizes a current pattern flowing through the power line.

7. The electricity storage pack according to claim 5 or 6.

8. When the measured contact resistance value exceeds a threshold value, the control unit of the electricity storage pack transmits an alert signal to the control unit of the charging device. The electricity storage pack according to any one of claims 5 to 7.

9. The electricity storage pack according to claim 1 , wherein the control unit of the electricity storage pack sets a value at which the measured contact resistance has converged as an official contact resistance value.

10. A motor; a control unit that performs authentication communication with a control unit of the power storage pack based on a pattern of a current flowing through a power line when the power storage pack for supplying power to the motor is attached to the electric vehicle; a control unit of the electric vehicle measures a contact resistance between the electric vehicle and the power storage pack based on a voltage of the power line on the electric vehicle side, a voltage of the power line on the power storage pack side received from the control unit of the power storage pack, and a current when performing authentication communication based on a pattern of a current flowing through the power line. An electrically powered vehicle.

11. The control unit of this electric vehicle includes: After the power storage pack is attached to the electric vehicle, when a signal transmitted by short-range wireless communication is received, a temporary connection is made to the control unit that is the destination of the signal, transmitting identification information to a control unit of the power storage pack attached to the electric vehicle according to a pattern of a current flowing through the power line; When a signal transmitted by the short-range wireless communication from the control unit of the temporarily connected power storage pack is received, a comparison is made to see whether or not identification information included in the received signal matches the transmitted identification information based on a pattern of a current flowing through the power line, and when they match, authentication is made that the power storage pack attached to the electric vehicle and the communication partner of the short-range wireless communication are the same; measuring the contact resistance during an authentication process utilizing a current pattern flowing through the power line; The electric vehicle according to claim 10 .

12. A notification unit for notifying information indicating a state of the electric vehicle, a control unit of the electric vehicle that, when the measured contact resistance exceeds a threshold value, causes the notification unit to notify information indicating a mounting error of the electricity storage pack; 12. The electric vehicle according to claim 10 or 11.

13. 13. The electric vehicle according to claim 10, wherein the control unit of the electric vehicle regards a value at which the measured contact resistance has converged as an official contact resistance value.

14. Charging slot and a control unit that performs authentication communication with a control unit of the power storage pack based on a pattern of a current flowing through a power line when the power storage pack is attached to the charging slot, a control unit of the charging device measures a contact resistance between the charging device and the electricity storage pack based on a voltage of the power line on the charging device side, a voltage of the power line on the electricity storage pack side received from the control unit of the electricity storage pack, and a current when performing authentication communication based on a pattern of a current flowing through the power line; A charging device characterized by:

15. The control unit of the charging device includes: When the power storage pack is attached to the charging slot and a signal transmitted by short-range wireless communication is received, a temporary connection is made to a control unit that is a destination of the signal, transmitting identification information to a control unit of the power storage pack attached to the charging slot based on a pattern of a current flowing through the power line; when receiving a signal transmitted by the short-range wireless communication from the control unit of the temporarily connected power storage pack, verifying whether or not identification information included in the received signal matches the identification information transmitted based on a pattern of a current flowing through the power line, and when they match, authenticating that the power storage pack attached to the charging slot and the communication partner of the short-range wireless communication are the same; measuring the contact resistance during an authentication process utilizing a current pattern flowing through the power line; 15. The charging device according to claim 14.

16. When the measured contact resistance exceeds a threshold value, the control unit of the charging device transmits an alert signal to a terminal device of an administrator of the charging device.

16. The charging device according to claim 14 or 15.

17. 17. The charging device according to claim 14, wherein the control unit of the charging device sets a value at which the measured contact resistance has converged as a formal value of the contact resistance.

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