Patent Description:
In recent years, electric motorcycles (electric scooters) and electric bicycles have become widespread. Usually, a portable battery pack capable of being mounted and unmounted is used in the electric motorcycle or the electric bicycle. When a battery is used as a power source of the motorcycle (scooter), a time required for energy supply is longer than a case where a liquid fuel such as gasoline is used (a charging time is longer than a fueling time).

Thus, when a state of charge of the battery pack decreases, it is considered that a mechanism for shortening the time required for energy supply is constructed by replacing a battery pack charged in advance with a battery pack having a reduced state of charge at the nearest charging stand.

Meanwhile, a method for confirming connection between a vehicle having an electricity storage device mounted thereon and an external power supply device by using wireless communication when the vehicle and the external power supply device are connected by a charging cable has been proposed (see, for example, PTL <NUM>).

Document <CIT> discloses a power storage pack authentication method reflecting the preamble of present claim <NUM>. Further art is disclosed by the documents <CIT> and <CIT>.

In the above method, it is assumed that the electricity storage device is fixed in the vehicle, and it is not assumed that the electricity storage device is removed from the vehicle. On the other hand, in the above mechanism involving the replacement of the battery pack, a circumstance in which there are a plurality of vehicles or a plurality of chargers in a range in which wireless communication with the battery pack can be performed may occur.

Under such a circumstance, there is a possibility that a controller of a certain vehicle erroneously controls a battery pack mounted in another adjacent vehicle. There is a possibility that a controller of the charger does not control the battery pack which is to be controlled and is mounted in a certain charging slot and erroneously controls the battery pack which is not to be controlled and is mounted in another charging slot. In such a case, safety and security of the entire charging system cannot be secured.

The present disclosure has been made in view of such a circumstance, and an object of the present disclosure is to provide a technique for correctly identifying a mounted power storage pack by an electric movable body or a charging device that controls the power storage pack by using wireless communication.

In order to solve the above problem, a power storage pack authentication method includes: transmitting via wire, by a controller of a first power storage pack, identification information retained in the first power storage pack to a controller of a charging device when the first power storage pack detached from an electric movable body is mounted in a first charging slot of the charging device; transmitting via wire, by the controller of the charging device, the identification information received from the first power storage pack to a controller of a second power storage pack which is replaceable with the first power storage pack and which is mounted in a second charging slot; transmitting via near-field communication, by the controller of the second power storage pack, a signal including the identification information received from the charging device when the second power storage pack detached from the second charging slot is mounted in the electric movable body; and collating, by a controller of the electric movable body, whether or not the identification information included in the received signal matches the identification information retained in the first power storage pack after the controller of the electric movable body receives the signal transmitted by the near-field communication, and authenticating that the second power storage pack mounted in the electric movable body is identical to a partner device communicating via the near-field communication when the identification information included in the received signal matches the identification information retained in the first power storage pack.

According to the present disclosure, the electric movable body or the charging device that controls the power storage pack by using wireless communication correctly identify the mounted power storage pack.

<FIG> is a conceptual diagram of vehicle system <NUM> using replaceable battery pack <NUM> according to an exemplary embodiment. Vehicle system <NUM> includes plural battery packs <NUM>, at least one charging device <NUM>, and plural vehicles <NUM> are used. In the present exemplary embodiment, an electric motorcycle (electric scooter) is assumed as vehicle <NUM>.

Battery pack <NUM> is a portable or replaceable battery pack capable of being mounted and detached, and can be mounted in a mounting slot of vehicle <NUM> and a charging slot of charging device <NUM>. Battery pack <NUM> is charged while being mounted in the charging slot of charging device <NUM>. Charged battery pack <NUM> is taken out by a user (usually, a driver of vehicle <NUM>) and is mounted in the mounting slot of vehicle <NUM>. Battery pack <NUM> mounted in the mounting slot of vehicle <NUM> is discharged during traveling of vehicle <NUM>, and has a state of charge reduced accordingly. Battery pack <NUM> having the reduced state of charge is taken out by the user and is mounted in the charging slot of charging device <NUM>. The user takes out charged battery pack <NUM> from another charging slot of charging device <NUM> and mounts the charged battery pack in the mounting slot of vehicle <NUM>. Battery pack <NUM> having the reduced state of charge is thus replaced with charged battery pack <NUM>. As a result, the user does not need to wait for the charging of battery pack <NUM>, and can restart the traveling of vehicle <NUM> in a short time.

In this method, since battery pack <NUM> is frequently mounted and detached, deterioration of a connector of battery pack <NUM> contacting a connector of the mounting slot of vehicle <NUM> or a connector of the charging slot of charging device <NUM> easily progresses. As a countermeasure, in the present exemplary embodiment, a control signal is transmitted and received between battery pack <NUM> and each of vehicle <NUM> and charging device <NUM> by wireless communication. As a result, a terminal for a communication line can be eliminated from a connector. A terminal for a power line may be provided in the connector. In the present exemplary embodiment, since wired communication via the connector is not used for the transmission and reception of the control signal, the control signal is prevented from being interrupted due to a connector defect.

Near-field communication is used for wireless communication between vehicle <NUM> and battery pack <NUM>, wireless communication between charging device <NUM> and battery pack <NUM>, and wireless communication between vehicle <NUM> and charging device <NUM>. Bluetooth°, Wi-Fi®, infrared communication, and the like may be used as the near-field communication. Hereinafter, in the present exemplary embodiment, it is assumed that Bluetooth° Low Energy (BLE) is used as the near-field communication.

The BLE is an extended standard of Bluetooth®, and is a low-power-consumption near-field communication standard using a <NUM> band. Since the BLE has low power consumption such that the battery pack may be powered for several years with a single button cell, the battery pack is suitable for battery powering, and the influence on the state of charge of battery pack <NUM> may be almost ignored. Since a lot of modules for BLE communication are put in the market, the modules may be obtained at low cost. The BLE has high affinity with a smartphone, and can provide various services in cooperation with the smartphone.

When a general class II device is used, a radio wave coverage of the BLE is about <NUM>. Therefore, plural vehicles <NUM>, plural battery packs <NUM>, and charging devices <NUM> may exist within a communication range of the BLE. Since the plural charging slots are provided in charging device <NUM>, charging device <NUM> needs to wirelessly communicate with plural battery packs <NUM> mounted in plural charging slots. That is, a <NUM>:N network is established between charging device <NUM> and each of plural battery packs <NUM>. Similarly, in the case that plural mounting slots are provided in vehicle <NUM>, vehicle <NUM> needs to wirelessly communicate with plural battery packs <NUM> mounted in the plural mounting slots. That is, a <NUM>:N network is established between vehicle <NUM> and each of the plural battery packs <NUM>.

Therefore, a mechanism for ensuring that battery pack <NUM> mounted in a specific charging slot of charging device <NUM> is required to be identical to battery pack <NUM> of a specific communication partner device of charging device <NUM>. Similarly, a mechanism for ensuring that battery pack <NUM> mounted in a specific mounting slot of vehicle <NUM> is required to be identical to battery pack <NUM> of a specific communication partner device of vehicle <NUM>. In the present exemplary embodiment, the identity between battery pack <NUM> physically connected and battery pack <NUM> connected by wireless communication is confirmed by identification information (ID). The identification information (ID) may be temporal identification information. The identification information (ID) may include identification information unique to each device.

<FIG> is a diagram illustrating a configuration example of charging device <NUM> according to the exemplary embodiment. Charging device <NUM> includes charging stand <NUM>, controller <NUM>, display unit <NUM>, operation unit <NUM>, and charging unit <NUM>. Controller <NUM> includes at least processing unit <NUM>, antenna <NUM>, and wireless communication unit <NUM>.

Charging stand <NUM> has plural charging slots SLc1 to SLc8 in which plural battery packs <NUM> are mounted, respectively. In the example illustrated in <FIG>, the number of charging slots is eight. The number of charging slots may be two or more, and may be four, for example.

Each of charging slots SLc1 to SLc8 includes a connector including a positive electrode terminal and a negative electrode terminal. When battery pack <NUM> is mounted, the charging slots are electrically conducted to a positive electrode terminal and a negative electrode terminal included in the connector of battery pack <NUM>, respectively. The negative electrode terminal included in the connector of each of charging slots SLc1 to SLc8 and the negative electrode terminal included in the connector of battery pack <NUM> may be solid grounds. In this case, pins included in the connector of battery pack <NUM> may be integrated with one of positive electrode terminal pins, and the number of projection portions of the connector with defect may be reduced.

Processing unit <NUM> (see <FIG>) of each battery pack <NUM> mounted in charging stand <NUM> transmits and receives a control signal to and from processing unit <NUM> in controller <NUM> via the near-field communication and a power line. A specific method for transmitting and receiving the control signal between the processing units will be described later.

The positive electrode terminal and the negative electrode terminal of each of charging slots SLc1 to SLc8 are connected to a positive electrode terminal and a negative electrode terminal of charging unit <NUM>, respectively. Charging unit <NUM> is connected to commercial power system <NUM>, and is configured to charge battery pack <NUM> mounted in charging stand <NUM>. Charging unit <NUM> generates direct-current (DC) power by performing full-wave rectifying of alternating-current (AC) power supplied from commercial power system <NUM> and smoothing the rectified AC power with a filter.

Relays (not illustrated) are provided between the positive electrode terminal and the negative electrode terminal of charging unit <NUM> and the positive electrode terminal and the negative electrode terminal of each of charging slots SLc1 to SLc8. Processing unit <NUM> controls control conduction or interruption of each of charging slots SLc1 to SLc8 by controlling turning on (closing) and turning off (opening) of each relay.

A DC/DC converter (not illustrated) may be provided between the positive electrode terminal and the negative electrode terminal of charging unit <NUM> and the positive electrode terminal and the negative electrode terminal of each of charging slots SLc1 to SLc8. In this case, processing unit <NUM> controls a charging voltage or a charging current of each battery pack <NUM> 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 battery pack <NUM>. When an AC/DC converter is mounted in battery pack <NUM>, battery pack <NUM> may be charged with AC power from charging unit <NUM>.

Processing unit <NUM> is, for example, a microcomputer. Wireless communication unit <NUM> executes a near-field communication process. In the present exemplary embodiment, wireless communication unit <NUM> includes a BLE module, and antenna <NUM> includes a chip antenna built in the BLE module or a pattern antenna. Wireless communication unit <NUM> outputs data received via near-field communication to processing unit <NUM>, and transmits data input from processing unit <NUM> via near-field communication.

Processing unit <NUM> may acquire battery state information from battery pack <NUM> mounted in charging stand <NUM>. At least one of voltage, current, temperature, state of charge (SOC), and state of health (SOH) of plural cells E1 to En (see <FIG>) in battery pack <NUM> can be acquired as the battery state information.

Display unit <NUM> includes a display, and displays guidance to the user (usually, the driver of vehicle <NUM>) who uses charging device <NUM> on the display. Operation unit <NUM> is a user interface such as a touch panel, and accepts an operation from the user. Charging device <NUM> may further include a loudspeaker (not illustrated) and may output audio guidance from the loudspeaker to the user.

<FIG> is a diagram illustrating a configuration example of vehicle <NUM> according to the exemplary embodiment. Vehicle <NUM> includes battery mounting unit <NUM>, vehicle controller <NUM>, meter panel <NUM>, inverter <NUM>, motor <NUM>, and tire <NUM>. Vehicle controller <NUM> includes at least processing unit <NUM>, antenna <NUM>, and wireless communication unit <NUM>.

Battery mounting unit <NUM> has at least one of mounting slots SLa1 and SLa2 for mounting at least one battery pack <NUM>. In the example illustrated in <FIG>, although the number of mounting slots is two, the number of mounting slots may be one or three or more.

Each of mounting slots SLa1 and SLa2 includes a connector including a positive electrode terminal and a negative electrode terminal, and when battery pack <NUM> is mounted, the mounting slots are electrically conducted to the positive electrode terminal and the negative electrode terminal included in the connector of battery pack <NUM>, respectively. The negative electrode terminal portion included in the connector of each of mounting slots SLa1 and SLa2 may be a solid GND.

Processing unit <NUM> (see <FIG>) of each battery pack <NUM> mounted in battery mounting unit <NUM> transmits and receives a control signal to and from processing unit <NUM> in vehicle controller <NUM> via near-field communication and a power line. A specific method for transmitting and receiving the control signal between the processing units will be described later.

The plural positive electrode terminals of the plural mounting slots SLa1 and SLa2 are connected to a positive-side power bus, and the plural negative electrode terminals are connected to a negative-side power bus. Therefore, the plural battery packs <NUM> mounted in the plural mounting slots SLa1 and SLa2 are electrically connected in parallel to one another. Therefore, as the number of battery packs <NUM> mounted in battery mounting unit <NUM> increases, the capacity increases. The plural battery packs <NUM> mounted in the plural mounting slots SLa1 and SLa2 may be electrically connected in series to one another. In this case, an output voltage is increased.

A positive electrode terminal and a negative electrode terminal of battery mounting unit <NUM> are connected to a positive electrode terminal and a negative electrode terminal of inverter <NUM>, respectively, via main relay RYm. Main relay RYm functions as a contactor between vehicle <NUM> and battery pack <NUM>. Processing unit <NUM> controls conduction or interruption between vehicle <NUM> and battery pack <NUM> by controlling turning on and off of main relay RYm.

Inverter <NUM> converts DC power supplied from battery pack <NUM> mounted in battery mounting unit <NUM> into AC power and supplies the AC power to motor <NUM> at the time of power running. The inverter converts AC power supplied from motor <NUM> into DC power and supplies the DC power to battery pack <NUM> mounted in battery mounting unit <NUM> at the time of regeneration. Motor <NUM> is a three-phase AC motor, and rotates in accordance with the AC power supplied from inverter <NUM> at the time of power running. At the time of regeneration, the motor converts rotational energy created by deceleration into AC power and supplies the AC power to inverter <NUM>. A rotary shaft of motor <NUM> is coupled to a rotary shaft of tire <NUM> of a rear wheel. A transmission may be provided between the rotary shaft of motor <NUM> and the rotary shaft of tire <NUM>.

Vehicle controller <NUM> is a vehicle electronic controller (ECU) configured to control entire vehicle <NUM>. Processing unit <NUM> of vehicle controller <NUM> includes a microcomputer. Wireless communication unit <NUM> executes a near-field communication process. In the present exemplary embodiment, wireless communication unit <NUM> includes a BLE module, and antenna <NUM> includes a chip antenna built in the BLE module or a pattern antenna. Wireless communication unit <NUM> outputs data received via near-field communication to processing unit <NUM>, and transmits data input from processing unit <NUM> via the near-field communication.

Processing unit <NUM> may acquire battery state information from battery pack <NUM> mounted in battery mounting unit <NUM>. Information of at least one of voltage, current, temperature, SOC, and SOH of plural cells E1 to En (see <FIG>) in battery pack <NUM> can be acquired as the battery state information. Processing unit <NUM> may acquire a speed of vehicle <NUM>.

Meter panel <NUM> displays state information of vehicle <NUM>. For example, the speed of vehicle <NUM> and the state of charge (SOC) of battery pack <NUM> are displayed. The driver may determine the necessity of replacement of battery pack <NUM> by looking at the state of charge (SOC) of battery pack <NUM> displayed on meter panel <NUM>.

<FIG> is a diagram illustrating a system configuration example of battery pack <NUM> mounted in vehicle <NUM> and vehicle controller <NUM> according to the exemplary embodiment. In the example illustrated in <FIG>, two battery packs 10a and 10b are mounted in battery mounting unit <NUM> of vehicle <NUM> (see <FIG>).

Battery pack <NUM> includes battery module <NUM> and battery controller <NUM>. Battery module <NUM> is connected on a power line internally connecting positive electrode terminal Tp to negative electrode terminal Tm of battery pack <NUM>. Positive electrode terminal Tp of battery pack <NUM> is connected to the positive-side power bus via slot relay RYs, and negative electrode terminal Tm of battery pack <NUM> is connected to the negative-side power bus. The positive-side power bus and the negative-side power bus are connected to inverter <NUM> via main relay RYm (see <FIG>).

Battery module <NUM> includes plural cells E1 to En connected in series to one another. Battery module <NUM> may include plural battery modules connected in series to one another or in series and parallel to one another. Each cell may be a lithium ion battery cell, a nickel metal hydride battery cell, a lead battery cell, or the like. Hereinafter, in this specification, the description is made by assuming an example where a lithium ion battery cell (having a nominal voltage of <NUM> V to <NUM> V) is used as the cell. The number of cells E1 to En is determined in accordance with a drive voltage of motor <NUM>.

A communication path is branched from node N1 between positive electrode terminal Tp of battery pack <NUM> and battery module <NUM>. Power relay RYp is inserted between node N1 and battery module <NUM>. Current sensor <NUM> is installed on the power line internally connecting positive electrode terminal Tp to negative electrode terminal Tm of battery pack <NUM>. Current sensor <NUM> is installed at a position closer to negative electrode terminal Tm than power relay RYp. Current sensor <NUM> is configured to measure a current flowing through battery module <NUM>, and outputs the measured current value to processing unit <NUM> of battery controller <NUM>. Current sensor <NUM> may include, for example, a combination of a shunt resistor, a differential amplifier, and an A/D converter. A Hall element may be used in place of the shunt resistor.

Battery controller <NUM> includes processing unit <NUM>, voltage measurement unit <NUM>, antenna <NUM>, and wireless communication unit <NUM>. Voltage measurement unit <NUM> is connected via plural voltage measurement lines to nodes between plural cells E1 to En, connected in series to one another. Voltage measurement unit <NUM> is configured to measure voltages of cells E1 to En by measuring each voltage between two adjacent voltage measurement lines. Voltage measurement unit <NUM> transmits the measured voltages of cells E1 to En to processing unit <NUM>.

Voltage measurement unit <NUM> has a higher voltage than processing unit <NUM> and hence, voltage measurement unit <NUM> is connected to processing unit <NUM> via a communication line while voltage measurement unit <NUM> is insulated from processing unit <NUM>. Voltage measurement unit <NUM> can be implemented by an application specific integrated circuit (ASIC) or a general-purpose analog front-end IC. Voltage measurement unit <NUM> includes a multiplexer and an A/D converter. The multiplexer outputs a voltage between two adjacent voltage measurement lines to the A/D converter in order from the top. The A/D converter converts analog voltages input from the multiplexer into digital values.

While not illustrated in <FIG>, at least one temperature sensor is installed near plural cells E1 to En. The temperature sensor measures the temperatures of cells E1 to En, and outputs the measured temperatures to processing unit <NUM>. The temperature sensor may include, for example, a combination of a thermistor, a voltage dividing resistor, and an A/D converter.

In the case that an A/D converter is mounted in processing unit <NUM> and an analog input port is installed in processing unit <NUM>, output values of current sensor <NUM> and the temperature sensor can be input, as analog values, to processing unit <NUM>.

Fitting detector <NUM> is configured to detect a fitting state between the connector of battery pack <NUM> and the connector of battery mounting unit <NUM> of vehicle <NUM>. For example, the connector of battery pack <NUM> may be a female connector, and the connector of battery mounting unit <NUM> of vehicle <NUM> may be a male connector. Fitting detector <NUM> outputs activation signals corresponding to connection states of both the connectors to processing unit <NUM>. The activation signal is defined by a binary signal: an ON signal output while both the connectors are connected to each other; and an OFF signal output while both the connectors are separated to each other. Fitting detector <NUM> may be implemented by, for example, a reed switch. In this case, fitting detector <NUM> magnetically determines whether both the connectors are connected to each other or not. The fitting detector may be implemented by a sensor configured to mechanically detect the presence or absence of connection between both the connectors may be used.

Wireless communication unit <NUM> executes a near-field communication process. In the present exemplary embodiment, wireless communication unit <NUM> includes a BLE module, and antenna <NUM> includes a chip antenna built in the BLE module or a pattern antenna. Wireless communication unit <NUM> is configured to output, to processing unit <NUM>, data received via near-field communication, and to transmit, via near-field communication, data input from processing unit <NUM>.

Node N1 between positive electrode terminal Tp of battery pack <NUM> and battery module <NUM> is connected to processing unit <NUM> via a communication path. Fuse F1, resistor R1, and pack-side communication relay RYc are connected in series to one another on the communication path. Fuse F1 is a protector preventing an overcurrent from flowing into processing unit <NUM> from the power line.

Processing unit <NUM> includes a microcomputer. Processing unit <NUM> is activated when the activation signal input from fitting detector <NUM> is turned on, and is shut down when the activation signal is turned off. Instead of shutdown, transition to a standby state or a sleep state may be performed.

Processing unit <NUM> controls conduction or interruption of the communication path between node N1 and processing unit <NUM> by controlling turning on and off of pack-side communication relay RYc. Processing unit <NUM> is configured to control states of cells E1 to En based on the voltage values, the current values, and the temperature values of the cells E1 to En measured by voltage measurement unit <NUM>, current sensor <NUM>, and the temperature sensor. For example, when overvoltage, undervoltage, overcurrent, high-temperature anomaly, or low-temperature anomaly occurs, processing unit <NUM> turns off power relay RYp to protect the cells E1 to En.

Processing unit <NUM> is configured to estimate the SOCs and the SOHs of cells E1 to En. Processing unit <NUM> is configured to estimate the SOCs by an open circuit voltage (OCV) method or a current integration method. The SOH is defined as a ratio of a current full charge capacity to an initial full charge capacity. The SOH having a lower value (closer to <NUM>%) indicates that degradation progresses more. The SOH may be obtained by measuring the capacity through full charging and discharging, or may be obtained by adding storage degradation and cycle degradation. The storage degradation may be estimated based on the SOC, the temperature, and a storage degradation rate. The cycle degradation may be estimated based on a range of the SOC in which the battery pack is used, a temperature, a current rate, and a cycle degradation rate. The storage degradation rate and the cycle degradation rate may be previously derived by experiments or simulations. The SOC, the temperature, the range of the range of the SOC, and the current rate may be obtained by measurement.

The SOH may be estimated based on a correlation between the SOH and an internal resistance of a cell. The internal resistance may be estimated by dividing, by the current value, a voltage drop that occurs when a predetermined current flows through the cell for a predetermined time. The internal resistance decreases as the temperature rises, and increases as the SOH decreases.

In the system configuration example illustrated in <FIG>, vehicle controller <NUM> includes processing unit <NUM>, relay controller <NUM>, antenna <NUM>, wireless communication unit <NUM>, and pack detector <NUM>. Relay controller <NUM> is configured to control turning on and off of main relay RYm, first slot relay RYsa, and second slot relay RYsb in response to an instruction from processing unit <NUM>.

Node Na between positive electrode terminal Tp of first battery pack 10a and first slot relay RYsa is connected to processing unit <NUM> of vehicle controller <NUM> via a communication path. Fuse F2a and first vehicle-side communication relay RYca are connected in series to each other on the communication path. Processing unit <NUM> controls conduction or interruption of the communication path between node Na and processing unit <NUM> by controlling turning on and off of first vehicle-side communication relay RYca.

Similarly, node Nb between positive electrode terminal Tp of second battery pack 10b and second slot relay RYsb is connected to processing unit <NUM> of vehicle controller <NUM> via a communication path. Fuse F2b and second vehicle-side communication relay RYcb are connected in series to each other on the communication path. Processing unit <NUM> controls conduction or interruption of the communication path between node Nb and processing unit <NUM> by controlling turning on and off of second vehicle-side communication relay RYcb.

In the case that three or more mounting slots are provided in battery mounting unit <NUM> of vehicle <NUM>, three or more slot relays RYs and three or more communication paths (fuse F2 and vehicle-side communication relay RYc) are provided in parallel.

First fitting detector 38a detects a fitting state between the connector of first mounting slot SLa1 of battery mounting unit <NUM> and the connector of first battery pack 10a, and outputs to pack detector <NUM> a detection signal indicating that these connectors are fitted. Similarly, second fitting detector 38b detects a fitting state between the connector of second mounting slot SLa2 of battery mounting unit <NUM> and the connector of second battery pack 10b, and outputs to pack detector <NUM> a detection signal indicating that these connectors are fitted. First fitting detector 38a and second fitting detector 38b may detect whether or not the connectors of the mounting slots are connected to the connectors of battery pack <NUM> by a magnetic method or a mechanical method.

Pack detector <NUM> outputs to processing unit <NUM> activation signals corresponding to detection signals input from fitting detectors 38a and 38b. When at least one of the detection signals indicates the connection state, pack detector <NUM> outputs an activation signal including a slot number of the connection state. When all of the detection signals indicate disconnection states, pack detector <NUM> controls the activation signal such that the activation signal is in an off state.

In an ignition-on state, processing unit <NUM> is activated when the activation signal input from pack detector <NUM> indicates that at least one battery pack <NUM> is mounted, and is shut down when the activation signal is turned off. Instead of shutdown, transition to a standby state or a sleep state may be performed.

In the system configuration example described above, processing unit <NUM> of vehicle controller <NUM> may transmit and receive a control signal to and from processing unit <NUM> of battery controller <NUM> via near-field communication.

Processing unit <NUM> of vehicle controller <NUM> may transmit and receive the control signal to and from processing unit <NUM> of battery controller <NUM> wiredly, i.e., via a wired path. When communication with processing unit <NUM> of first battery pack 10a is wiredly performed, processing unit <NUM> of vehicle controller <NUM> turns off first slot relay RYsa and turns on first vehicle-side communication relay RYca. Processing unit <NUM> of first battery pack 10a turns off power relay RYp and turns on pack-side communication relay RYc of first battery pack 10a. In this state, the wired path between processing unit <NUM> of vehicle controller <NUM> and processing unit <NUM> of first battery pack 10a is electrically conducted while being insulated from vehicle <NUM> and a high-voltage unit of battery pack <NUM>. Therefore, serial communication may be performed between processing unit <NUM> of vehicle controller <NUM> and processing unit <NUM> of first battery pack 10a at a voltage (for example, less than or equal to a voltage of 5V) corresponding to an operating voltage of the processing unit.

Similarly, when communication with processing unit <NUM> of second battery pack 10b is performed wiredly, via a wire, processing unit <NUM> of vehicle controller <NUM> turns off second slot relay RYsb and turns on second vehicle-side communication relay RYcb. Processing unit <NUM> of second battery pack 10b turns off power relay RYp and turns on pack-side communication relay RYc in second battery pack 10b. In this state, the wired path between processing unit <NUM> of vehicle controller <NUM> and processing unit <NUM> of second battery pack 10b is electrically conducted while being insulated from vehicle <NUM> and the high-voltage unit of battery pack <NUM>.

While not illustrated in <FIG>, the same configuration as vehicle controller <NUM> illustrated in <FIG> is also provided in controller <NUM> of charging device <NUM>. Processing unit <NUM> of charging device <NUM> may transmit and receive a control signal to and from processing unit <NUM> of battery controller <NUM> via near-field communication. Processing unit <NUM> of charging device <NUM> may transmit and receive the control signal to and from processing unit <NUM> of battery controller <NUM> wiredly, via a wired path.

<FIG> is a diagram illustrating a basic concept of a process of authenticating, by vehicle controller <NUM>, battery pack <NUM> mounted in mounting slot SLa of vehicle <NUM>. Vehicle controller <NUM> is basically configured to identify battery pack <NUM> by searching for a radio wave of the near-field communication transmitted from battery pack <NUM>. Specifically, when battery pack <NUM> is mounted in mounting slot SLa, vehicle controller <NUM> wiredly transmits ID1. Upon wiredly receiving the ID1 from vehicle controller <NUM>, battery controller <NUM> of battery pack <NUM> transmits a signal including the ID1 via near-field communication.

Upon receiving the signal via the near-field communication, vehicle controller <NUM> collates the ID included in the received signal with ID1 previously transmitted wiredly. When both the IDs match, vehicle controller <NUM> authenticates that battery pack <NUM> mounted in mounting slot SLa is identical to a partner device communicating via the near-field communication. When both the IDs do not match, vehicle controller <NUM> determines that the partner device communicating via the near-field communication is not identical to battery pack <NUM> mounted in mounting slot SLa, and does not authenticate battery pack <NUM> of the partner device. For example, when a signal including ID2 is received, since the ID does not match ID1 transmitted wiredly, battery pack <NUM> which has transmitted the signal including the ID2 is not authenticated.

Vehicle controller <NUM> may determine identity between battery pack <NUM> mounted in mounting slot SLa and the partner device communicating via the near-field communication by transmitting the ID via the near-field communication and collating the transmitted ID with the ID received wiredly from battery controller <NUM> of battery pack <NUM>.

A basic concept of the process of authenticating, by vehicle controller <NUM>, battery pack <NUM> mounted in mounting slot SLa of vehicle <NUM> has been described above, the same is applicable to a case where controller <NUM> of charging device <NUM> authenticates battery pack <NUM> mounted in charging slot SLc of charging device <NUM>.

<FIG> is a diagram schematically illustrating a flow of ID assignment to battery pack <NUM> after replacement when battery pack <NUM> mounted in mounting slot SLa of vehicle <NUM> is replaced. In state <NUM>, first charging slot SLc1 of charging device <NUM> is an empty slot, and charged second battery pack 10b is mounted in second charging slot SLc2. First battery pack 10a having a reduced state of charge is mounted in first mounting slot SLa1 of vehicle <NUM>. First battery pack 10a includes a vehicle ID authenticated by vehicle controller <NUM>. The vehicle ID ensures the identity between first battery pack 10a as a physical connection partner device and first battery pack 10a as a connection partner device of wireless communication as viewed from vehicle <NUM>.

In state <NUM>, the user (usually, the driver of vehicle <NUM>) detaches first battery pack 10a from first mounting slot SLa1 of vehicle <NUM>, and detached first battery pack 10a is mounted in first charging slot SLc1 of charging device <NUM>. When first battery pack 10a is rented, a work of returning first battery pack 10a to charging device <NUM> is performed. When first battery pack 10a is mounted in first charging slot SLc1 of charging device <NUM>, battery controller <NUM> of first battery pack 10a transmits the vehicle ID retained therein to controller <NUM> of charging device <NUM>.

In state <NUM>, controller <NUM> of charging device <NUM> transmits, to battery controller <NUM> of second battery pack 10b, the vehicle ID received from battery controller <NUM> of first battery pack 10a, and writes the vehicle ID to battery controller <NUM> of second battery pack 10b.

In state <NUM>, the user detaches second battery pack 10b from second charging slot SLc2 of charging device <NUM>, and detached second battery pack 10b is mounted in first mounting slot SLa1 of vehicle <NUM>. Battery pack <NUM> mounted in first mounting slot SLa1 of vehicle <NUM> is thus physically replaced. Since second battery pack 10b already has the vehicle ID, identity between second battery pack 10b as a physical connection partner device and second battery pack 10b as a partner device communicating wirelessly as viewed from vehicle <NUM> is secured.

<FIG> is a sequence diagram illustrating a detailed process flow when battery pack <NUM> mounted in mounting slot SLa of vehicle <NUM> is replaced (part <NUM>). <FIG> is a sequence diagram illustrating a detailed process flow when battery pack <NUM> mounted in mounting slot SLa of vehicle <NUM> is replaced (part <NUM>). In horizontal lines in the following sequence diagrams, thin dotted lines denote wireless communication, thin solid lines denote wired communication, thick dotted lines denote physical movement of the battery pack, and thick solid lines denote charging and discharging of battery packs.

First charging slot SLc1 of charging device <NUM> is an empty slot, and second battery pack 10b is mounted in second charging slot SLc2. Second battery pack 10b includes a charging ID1 authenticated by controller <NUM> of charging device <NUM>. The charging ID1 ensures identity between second battery pack 10b as a physical connection partner device and second battery pack 10b as a partner device communicating wirelessly as viewed from charging device <NUM>.

Charging device <NUM> charges second battery pack 10b mounted in second charging slot SLc2. That is, a charging current flows from charging unit <NUM> to second battery pack 10b mounted in second charging slot SLc2. When the SOC of second battery pack 10b reaches an upper limit value, the charging is ended. The upper limit value may be an SOC corresponding to a full charge capacity or an SOC lower than the full charge capacity (for example, <NUM>%).

First battery pack 10a is mounted in first mounting slot SLa1 of vehicle <NUM>. First battery pack 10a includes a vehicle ID authenticated by vehicle controller <NUM>. The vehicle ID ensures identity between first battery pack 10a as a physical connection partner device and first battery pack 10a as a connection partner device of wireless communication as viewed from vehicle <NUM>. While vehicle <NUM> travels, a discharge current flows from first battery pack 10a to motor <NUM> via inverter <NUM>. The SOC of first battery pack 10a decreases as vehicle <NUM> travels.

When an ignition-off operation is performed by the user (usually, the driver of vehicle <NUM>), vehicle controller <NUM> accepts the ignition-off operation (P3a). Upon accepting the ignition off operation, vehicle controller <NUM> transmits a shutdown instruction to battery controller <NUM> of first battery pack 10a via near-field communication. Upon receiving the shutdown instruction from vehicle controller <NUM>, battery controller <NUM> of first battery pack 10a is shut down (P3b).

After first battery pack 10a is unmounted from first mounting slot SLa1 of vehicle <NUM> by the user and first battery pack 10a is mounted in first charging slot SLc1 of charging device <NUM>, fitting detector <NUM> of first battery pack 10a detects the fitting in first charging slot SLc1 (P3c), and battery controller <NUM> of first battery pack 10a is activated (P3e). Controller <NUM> of charging device <NUM> detects that battery pack <NUM> is mounted in first charging slot SLc1 (P3d).

Battery controller <NUM> of first battery pack 10a notifies, of the vehicle ID, controller <NUM> of charging device <NUM> wiredly (P3f). The notification of the vehicle ID may be performed by copying or moving the vehicle ID. In a case where the notification is performed by moving the vehicle ID, battery controller <NUM> of first battery pack 10a notifies controller <NUM> of charging device <NUM> of the vehicle ID, and deletes the vehicle ID from battery controller <NUM> of first battery pack 10a.

Controller <NUM> of charging device <NUM> wiredly transmits a charging ID2 to battery controller <NUM> of first battery pack 10a mounted in first charging slot SLc1, and writes the charging ID2 to battery controller <NUM> of first battery pack 10a (P3g). When battery controller <NUM> of first battery pack 10a receives the charging ID2, battery controller <NUM> serves as a beacon terminal (peripheral terminal) and executes advertising via near-field communication (P3h). Specifically, battery controller <NUM> transmits periodically at constant intervals an advertisement packet including the charging ID2 received wiredly, as a beacon packet. The advertisement packet functions as a signal for notifying controller <NUM> of charging device <NUM> as the central terminal or vehicle controller <NUM> of vehicle <NUM> of the presence of the host vehicle.

Upon receiving the advertisement packet, controller <NUM> of charging device <NUM> collates the charging ID included in the received advertisement packet with the charging ID previously transmitted wiredly (P3i). In the example illustrated in <FIG>, when the charging ID included in the received advertisement packet is the charging ID2, the collation succeeds. When the charging ID is not the charging ID2, the collation does not succeed, thus failing. When the collation fails, controller <NUM> of charging device <NUM> continues scanning of the advertisement packet. When the collation succeeds, controller <NUM> of charging device <NUM> starts a connection process to be connected to battery controller <NUM> of first battery pack 10a (P3j).

First, controller <NUM> of charging device <NUM> transmits a connection request to battery controller <NUM> of first battery pack 10a. Subsequently, encryption parameters (for example, the number of digits of an encryption key and an encryption level) are exchanged between controller <NUM> of charging device <NUM> and battery controller <NUM> of first battery pack 10a. Battery controller <NUM> of first battery pack 10a generates an encryption key used to encrypt communication data based on the exchanged encryption parameter (P3k). Controller <NUM> of charging device <NUM> generates an encryption key used to encrypt the communication data based on the exchanged encryption parameter (P3l). Finally, the generated encryption keys are exchanged between controller <NUM> of charging device <NUM> and battery controller <NUM> of first battery pack 10a. As a result, pairing between controller <NUM> of charging device <NUM> and battery controller <NUM> of first battery pack 10a is completed (P3m). The completion of the pairing completes a process of returning first battery pack 10a to charging device <NUM>.

Controller <NUM> of charging device <NUM> selects another battery pack <NUM> with which first battery pack 10a is replaced (P3n). Specifically, controller <NUM> of charging device <NUM> selects one of charged battery packs <NUM> mounted in the charging slots SLc of charging stand <NUM>. In the example illustrated in <FIG>, charged second battery pack 10b mounted in second charging slot SLc2 is selected.

Controller <NUM> of charging device <NUM> wiredly transmits, to battery controller <NUM> of selected second battery pack 10b, the vehicle ID which has been acquired from battery controller <NUM> of first battery pack 10a, and writes the vehicle ID to battery controller <NUM> of second battery pack 10b (P3o).

Controller <NUM> of charging device <NUM> transmits a shutdown instruction to battery controller <NUM> of selected second battery pack 10b via near-field communication, and executes a disconnection process to be disconnected from battery controller <NUM> of second battery pack 10b (P3p). Upon receiving the shutdown instruction from controller <NUM> of charging device <NUM>, battery controller <NUM> of second battery pack 10b is shut down (P3q). Battery controller <NUM> of second battery pack 10b transmits a shutdown completion notification to controller <NUM> of charging device <NUM> immediately before being shut down.

Upon receiving the shutdown completion notification from battery controller <NUM> of second battery pack 10b, controller <NUM> of charging device <NUM> instructs the user of vehicle <NUM> to detach second battery pack 10b mounted in second charging slot SLc2 (P3r). For example, controller <NUM> of charging device <NUM> causes display unit <NUM> to display a message instructing the user to detach second battery pack 10b mounted in second charging slot SLc2. At this moment, controller <NUM> of charging device <NUM> may output audio guidance from a loudspeaker (not illustrated) to the user. Only a lamp (not illustrated) of second charging slot SLc2 may be turned on or off. Only a lamp (not illustrated) of second charging slot SLc2 may be turned on in a color different from color of the lamp of the other charging slot.

When second battery pack 10b is detached from second charging slot SLc2 and second battery pack 10b is mounted in first mounting slot SLa1 of vehicle <NUM> by the user, fitting detector <NUM> of second battery pack 10b detects fitting to first mounting slot SLa1 (P3s), and battery controller <NUM> of second battery pack 10b is activated (P3u). When fitting detector <NUM> of vehicle <NUM> detects that battery pack <NUM> is mounted in first mounting slot SLa1 (P3t), vehicle controller <NUM> is activated (P3v).

Controller <NUM> of charging device <NUM> starts charging control of first battery pack 10a mounted in first charging slot SLc1 (P3w). Specifically, controller <NUM> of charging device <NUM> transmits a charging instruction to battery controller <NUM> of first battery pack 10a via near-field communication, and turns on second slot relay RYsb. Upon receiving the charging instruction, battery controller <NUM> of first battery pack 10a turns on power relay RYp. As a result, a charging current flows from charging unit <NUM> of charging device <NUM> to first battery pack 10a mounted in first charging slot SLc1.

Battery controller <NUM> of second battery pack 10b serves as a beacon terminal and executes advertising via near-field communication (P3z). Specifically, battery controller <NUM> transmits periodically at constant intervals, as a beacon packet, an advertisement packet including the vehicle ID written by controller <NUM> of charging device <NUM>.

Upon receiving the advertisement packet, vehicle controller <NUM> collates the vehicle ID included in the received advertisement packet with the vehicle ID assigned to first battery pack 10a (P3A). When the collation of the vehicle ID fails, vehicle controller <NUM> continues scanning of the advertisement packet. When the collation of the vehicle IDs succeeds, vehicle controller <NUM> starts a connection process to be connected to battery controller <NUM> of second battery pack 10b (P3B).

First, vehicle controller <NUM> transmits a connection request to battery controller <NUM> of second battery pack 10b. Subsequently, encryption parameters are exchanged between vehicle controller <NUM> and battery controller <NUM> of second battery pack 10b. Battery controller <NUM> of second battery pack 10b generates an encryption key used to encrypt the communication data based on the exchanged encryption parameter (P3C). Vehicle controller <NUM> generates an encryption key used to encrypt communication data based on the exchanged encryption parameter (P3D). Finally, the generated encryption keys are exchanged between vehicle controller <NUM> and battery controller <NUM> of second battery pack 10b, thereby completing a pairing between vehicle controller <NUM> and battery controller <NUM> of second battery pack 10b (P3E). After the pairing is completed, vehicle controller <NUM> transmits a shutdown instruction to battery controller <NUM> of second battery pack 10b via near-field communication. Upon receiving the shutdown instruction from vehicle controller <NUM>, battery controller <NUM> of second battery pack 10b is shut down (P3F).

<FIG> is a sequence diagram illustrating a process flow according to a modification of the process illustrated in <FIG>. In the modification illustrated in <FIG>, a mechanism for enhancing the reliability of the authentication process by vehicle controller <NUM> of battery pack <NUM> mounted in first mounting slot SLa1 is introduced. Hereinafter, differences from the process illustrated in <FIG> will be described.

When battery controller <NUM> of second battery pack 10b is activated in process P3u and vehicle controller <NUM> is activated in process P3v, vehicle controller <NUM> wiredly transmits the vehicle ID assigned to first battery pack 10a to battery controller <NUM> of second battery pack 10b, and writes the vehicle ID to battery controller <NUM> of second battery pack 10b (P3x).

Upon wiredly receiving the vehicle ID from vehicle controller <NUM>, battery controller <NUM> of second battery pack 10b collates the vehicle ID received from vehicle controller <NUM> with the vehicle ID written by controller <NUM> of charging device <NUM> (P3y). Battery controller <NUM> of second battery pack 10b wiredly transmits the collation result to vehicle controller <NUM>. When the collation fails, battery controller <NUM> of second battery pack 10b transitions to a standby mode. Vehicle controller <NUM> displays, on meter panel <NUM>, a warning that incorrect battery pack <NUM> is mounted in first mounting slot SLa1. After visually confirming the displayed warning, the user returns incorrectly mounted battery pack <NUM> to charging device <NUM>, detaches correct battery pack <NUM> from charging device <NUM>, and mounts the detached battery pack to first mounting slot SLa1. When new battery pack <NUM> is mounted in first mounting slot SLa1, the process returns to process P3s and process P3t.

In this modification, a process of wiredly transmitting the vehicle ID from vehicle controller <NUM> to battery controller <NUM> of battery pack <NUM> is added. This process prevents vehicle controller <NUM> and battery controller <NUM> of battery pack <NUM> mounted in adjacent vehicle <NUM> from being incorrectly paired.

As described above, in the present exemplary embodiment, when battery pack <NUM> mounted in vehicle <NUM> is detached and returned to charging device <NUM>, the vehicle ID in battery pack <NUM> is written to anther battery pack <NUM> for replacement via charging device <NUM>. As a result, when battery pack <NUM> for replacement is mounted in vehicle <NUM>, vehicle <NUM> correctly identifies mounted battery pack <NUM> based on the vehicle ID. This configuration provides no malfunction, such as erroneous control of battery pack <NUM> mounted in another nearby vehicle <NUM> by vehicle controller <NUM> of certain vehicle <NUM>, and secures the safety and security of entire vehicle system <NUM> using replaceable battery pack <NUM> and charging device <NUM>. The user safely drives vehicle <NUM> only by detaching battery pack <NUM> mounted in charging device <NUM> and mounting the battery pack in vehicle <NUM>.

Since the vehicle ID in battery pack <NUM> returned to charging device <NUM> is written to another battery pack <NUM> for replacement via charging device <NUM> and reused, vehicle <NUM> that can use battery pack <NUM> for replacement is limited to vehicle <NUM> in which returned battery pack <NUM> is mounted. This configuration prevents the use of illegally acquired battery pack <NUM> (for example, stolen battery pack <NUM>).

The control signals are transmitted and received between battery pack <NUM> and each of vehicle <NUM> and charging device <NUM> via near-field communication. This configuration reduces the number of pins included in the connector of battery pack <NUM>. As a result, it is possible to reduce a mechanical connection failure between battery pack <NUM> and each of vehicle <NUM> and charging device <NUM>. Firmware used in battery controller <NUM> of battery pack <NUM> can be updated via wireless communication, and the firmware can be easily updated.

The present disclosure has been described above according to the exemplary embodiment. It will be understood by those who are skilled in art that the exemplary embodiment is merely an example, that combinations of constituent elements and processes included in the exemplary embodiment may be modified in various forms, and that such modifications are also within the scope of the present disclosure.

The above-described exemplary embodiment has described an example of using battery pack <NUM> incorporating battery module <NUM> including the lithium ion battery cell, the nickel hydrogen battery cell, the lead battery cell, or the like. In this regard, a capacitor pack incorporating a capacitor module including an electric double layer capacitor cell, a lithium ion capacitor cell, or the like may be used. In this specification, the battery pack and the capacitor pack are collectively referred to as a power storage pack. Each relay in the above-described exemplary embodiment may be appropriately replaced with a semiconductor switch.

In the above-described exemplary embodiment, an electric motorcycle (electric scooter) is assumed as vehicle <NUM> using replaceable battery pack <NUM> as a power source. In this respect, vehicle <NUM> may be an electric bicycle. Vehicle <NUM> may be a four-wheeled electric automobile (EV). The electric automobile includes not only a full-standard electric automobile but also a low-speed electric automobile such as a golf cart or a land car used in a shopping mall or an entertainment facility.

Claim 1:
A power storage pack authentication method comprising:
transmitting via wire, by a controller of a first power storage pack (10a), identification information retained in the first power storage pack (10a) to a controller of a charging device (<NUM>) when the first power storage pack (10a) detached from an electric movable body (<NUM>) is mounted in a first charging slot of the charging device (<NUM>);
transmitting via wire, by the controller of the charging device (<NUM>), the identification information received from the first power storage pack (10a) to a controller of a second power storage pack (10b) which is replaceable with the first power storage pack (10a) and which is mounted in a second charging slot;
characterized in that the power storage pack authentication method further comprises:
transmitting via near-field communication, by the controller of the second power storage pack (10b), a signal including the identification information received from the charging device (<NUM>) when the second power storage pack detached from the second charging slot is mounted in the electric movable body (<NUM>); and
collating, by a controller of the electric movable body (<NUM>), whether or not the identification information included in the received signal matches the identification information retained in the first power storage pack (10a) after the controller of the electric movable body (<NUM>) receives the signal transmitted by the near-field communication, and
authenticating that the second power storage pack (10b) mounted in the electric movable body (<NUM>) is identical to a partner device communicating via the near-field communication when the identification information included in the received signal matches the identification information retained in the first power storage pack (10a).