Abstract: The present teaching relates to method and system for charging a rechargeable battery deployed in an electric apparatus. The system resides in the electric apparatus. The system comprises a motor, an inverter, an output rectifier, a configurator, and a controller. The motor comprises a stator having a plurality of stator teeth and a plurality of stator windings wounded on the plurality of stator teeth. The inverter comprises a plurality of power switch devices. The configurator has contactors coupled with the plurality of stator windings and the plurality of power switch devices. The controller controls the plurality of power switch devices and the plurality of contactors, configuring the system to operate in one of a traction mode and a charging mode, where in the charging mode a voltage and/or current regulation occurs using the plurality of power switch devices.

Abstract: This disclosure describes apparatuses and techniques for a switched multi-cell battery system for electronic devices. In some aspects, a switched multi-cell battery system may transfer, via a plurality of power control switches electrical power from a power adapter to components of the electronic device by charging battery cells in series and by discharging the battery cells in parallel or as a single battery cell. As a result, the switched multi-cell battery system may reduce or eliminate a voltage step-down conversion stage to increase a power-transfer efficiency of an electronic device. By doing so, charging times may be reduced or operating times may be increased, thereby improving users' experience with their electronic devices.

Abstract: An embodiment system for charging an electric motor vehicle includes a first switching circuit configured to select one of at least two chargers, a second switching circuit configured to select a charging station connector to be connected to the charger selected by the first switching circuit, and a controller configured to control the first switching circuit and the second switching circuit based on a predetermined charging order to allow charging of a battery of a vehicle that is connected to the charging station connector to be performed, sense connection of a charging connector of the vehicle to the charging station connector, receive a required charging amount and an available waiting time of the vehicle, and determine the charging order based on the required charging amount and the available waiting time.

Abstract: A battery management system is provided with a first charging circuit including a first switch to connect a first battery pack to a power source. A second charging circuit includes a second switch to connect a second battery pack to the power source, wherein the second charging circuit is arranged in parallel with the first charging circuit. A discharge circuit includes a discharge switch to connect the first battery pack and the second battery pack in series. A processor is programmed to: open the discharge switch; receive input indicative of a first battery voltage and a second battery voltage; close the first switch and open the second switch in response to the first battery voltage being less than the second battery voltage; and close the first switch and close the second switch in response to the first battery voltage being approximately equal to the second battery voltage.

Abstract: A modular wireless appliance charging system includes a charging platform having a plurality of adapter slots disposed on its upper side. An adapter is configured to be removably secured within each adapter slot. Each adapter includes a receiver configured to removably secure an appliance to the adapter via a charging port of the appliance. A power supply is operably connected to a charging mechanism which is configured to charge the battery of the appliance that is secured to the receiver of an adapter that is secured within one of the adapter slots. An auxiliary platform having similar components can be connected to the primary platform to expand the system's charging capacity. The adapters can include many configurations for different types of appliances. In this way, the user can customize their charging system to include a specific type, number, and order of adapters for organizing and charging their battery-powered appliances.

Abstract: A charge control device for charging a battery with electric power supplied from an external power supply includes: an external power supply information acquisition unit that acquires external power supply information including a voltage of the external power supply; a battery information acquisition unit that acquires battery information including a temperature, a voltage, and an electric current of the battery; a power consumption acquisition unit that acquires an amount of electric power supplied from the battery to an auxiliary device as a power consumption amount; and a charge time estimation unit that estimates a charge time of the battery. The charge time estimation unit acquires an initial value of a state of charge of the battery based on the battery information, and estimates the charge time based on the battery temperature, the external power supply information, the power consumption amount, and the initial value of the state of charge.

Abstract: An all-solid-state secondary battery including: a cathode including a cathode active material layer; an anode including an anode current collector, and an anode active material layer on the anode current collector, wherein the anode active material layer includes an anode active material which is alloyable with lithium or forms a compound with lithium; and a solid electrolyte layer between the cathode and the anode, wherein a ratio of an initial charge capacity (b) of the anode active material layer to an initial charge capacity (a) of the cathode active material layer satisfies a condition of Equation 1: 0.01<(b/a)<0.5, wherein a is the initial charge capacity of the cathode active material layer determined from a first open circuit voltage to a maximum charging voltage, and b is the initial charge capacity of the anode active material layer determined from a second open circuit voltage to 0.01 volts vs. Li/Li+.

Abstract: A portable programmable display and control module which serves as a basic light switch and a digital custom light switch display. The control module can be removed from the electrical box when power fails to provide for an emergency flashlight. The control module can be provided with a mini-hard drive and microprocessor in order to be able to download digital content and display it on a lighted touch screen. The control module can also be controlled and programmed wirelessly by a computer or smart phone to control light switches, outlets, and other devices. The control module can also include a built-in solar cell to charge the module for prolonged power failures. A battery back-up can also be provided. The module can be provided with a front camera and a rear camera and can be used in emergency events to transmit images and video to first responders.

Abstract: A battery management system includes multiple monitoring devices and a control device. The monitoring devices are disposed in a housing that accommodates a battery of a vehicle and monitors battery information indicating a state of the battery. The control device performs wireless communication with each of the monitoring devices and acquires data including the battery information to execute a predetermined process. The control device sets a cycle in which the multiple monitoring devices make a round in order to perform wireless communication with each of the monitoring devices, and is capable of adjusting the cycle.

Abstract: In various embodiments, a battery fuel gauge includes a processor. The processor can be configured to obtain information relating to expansion of a battery and to determine a state of charge and/or a state of health of the battery based at least in part on the expansion of the battery. In certain embodiments, a battery management system can be configured to control charging/discharging and/or cooling/heating of one or more cells in the battery based at least in part on the expansion of the battery.

Abstract: A system and method for remotely monitoring, measuring and controlling power to an electrically powered device is disclosed herein. The system preferably comprises an apparatus, an electrically-powered device and a controller. The apparatus preferably comprises a cord, an alternating current outlet socket, an alternating current input plug, an electro-mechanical relay, a processor and a transceiver. The system preferably uses a WiFi communication signal to transmit commands from the remote controller to the apparatus.

Abstract: Techniques are described for controlling charging of an electric vehicle. According to one or more embodiments, a system is provided comprising a memory that stores computer executable components and a processor that executes the computer executable components stored in the memory, wherein the computer executable components comprise a signaling component located on an electric vehicle and configured to detect a presence of a portable device and a charge control component configured to, upon detection of the presence of the portable device, terminate charging of the electric vehicle.

Abstract: A system for servicing watercraft includes one or more waterborne platforms. Each waterborne platform includes an electric power supply, a driving system for moving the waterborne platform in a body of water, a watercraft interfacing system configured to at least supply electric power to an electrically-powered watercraft, and a control interface configured to exchange data with a controller. The controller is configured to: receive input data, determine respective destination locations for the waterborne platforms to supply electric power to the electrically-powered watercraft, and send control data that includes data indicating the destination locations to the waterborne platforms.

Abstract: A battery module assembly, a battery pack, and a device using a battery as a power source are provided. The battery module assembly includes: at least two battery modules arranged along a first direction, each of the battery modules including a plurality of battery cells, and a shell side wall of the battery cell including two oppositely arranged first side walls and two oppositely arranged second side walls, an area of the first side wall being larger than that of the second side wall, and the first side wall being perpendicular to the first direction; and a cooling plate arranged between two adjacent battery modules, and configured to perform heat exchange with the first side walls of the battery cells of the two adjacent battery modules. The battery pack includes the battery module assembly. The device using a battery as a power source includes the battery pack.

Abstract: Disclosed herein is a wireless power reception system that utilizes a switched capacitor DC-DC voltage converter to charge a load. Current sensing circuits described herein enable the measurement of the input current to the switched capacitor DC-DC voltage converter while being relatively insensitive to temperature variation. Voltage/current sensing circuits described herein enable the selective measurement of load voltage, high side load current, and low side load current. One of the current sensing circuits may be used together with one of the voltage/current sensing circuits in a single device, or the current sensing circuits and voltage/current sensing circuits may be used separately in different devices.

Abstract: The present invention is an electric vehicle charger-mounted transformer with a system that enables AC power generated from the lower voltage side of the transformer to be converted into electric vehicle charging power, and at the same time, the electric vehicle to be charged, and in more detail, an electric vehicle charger includes a slow-charging device and a fast-charging device, the slow-charging device and the fast-charging device are connected to automatic fire extinguishing devices, respectively, and the automatic fire extinguishing devices automatically operate when the automatic fire extinguishing devices detect that at least one of a temperature of the slow-charging device and a temperature of the fast-charging device rises above a given temperature or detect generation of smoke.

Abstract: A charging method, a battery management system for a traction battery and a charging pile are provided, which can effectively ensure normal charging of an electric vehicle. The charging method is used for charging a traction battery, and the method includes: determining, by the battery management system (BMS) of the traction battery, a pulse charging demand parameter according to a battery state parameter of the traction battery; and sending a pulse charging information to a charging pile by the BMS, the pulse charging information including the pulse charging demand parameter for indicating the charging pile to output a pulse current for charging the traction battery.

Abstract: A battery management apparatus includes a plurality of battery cells connected to one another in at least one of a series connection or a parallel connection; a detector configured to detect electrical signals of the battery cells; a monitor configured to obtain the electrical signal for each of the battery cells and values of correlation coefficient corresponding to correlation results obtained based on the electrical signals, and to generate identification signals corresponding to the electrical signals of the battery cells based on the values of correlation coefficient and a reference value; and a storage configured to store the identification signals generated by the monitor for each of the battery cells. The monitor is configured to recognize a risk of failure of each of the battery cells based on an accumulated number of identification signals stored in the storage for each of the battery cells.

Abstract: An inflatable equipment with a starting power supply is disclosed, which belongs to the technical field of inflatable equipments. The inflatable equipment with a starting power supply includes a housing; a battery pack, fixedly provided in the housing, and the housing is fixedly provided with a connection interface electrically connected to the battery pack; and an inflator pump module, fixedly provided in the housing. Herein the inflator pump module is electrically connected to the battery pack, the housing is opened with an air inlet, an input end of the inflator pump module is connected to the air inlet, the housing is fixedly provided with an inflatable interface, and the inflatable interface is connected to an output end of the inflator pump module. The inflatable equipment has a compact and small structure, which is easy to be stored and carried, thereby improving user's experience.

Abstract: A multi-input charging system and method use a motor driving device. The system includes: a motor having a plurality of windings; a first inverter including first switching elements and having one end connected to a power input terminal and an opposite end connected to a first terminal of each of the plurality of windings; a second inverter including second switching elements and having one end connected to a battery and an opposite end connected to a second terminal of each of the plurality of windings, the battery connected to the power input terminal or the one end of the second inverter; and a controller configured to charge the battery directly via the power input terminal or with a voltage of the charging power that is stepped down.

Abstract: A charging system based on a master-slave relationship includes a master charging device coupled with a target device, and at least one slave charging device electrically connected with the master charging device. An edge slave charging device among the at least one slave charging device is coupled with a power source. The master charging device determines a power-output distribution of the master charging device and the at least one slave charging device, and notifies the at least one slave charging device of the power-output distribution. The at least one slave charging device provides a supplementary power to the master charging device according to the power-output distribution. The master charging device further provides a specific power for the target device based on the supplementary power, so as to charge the target device in cooperation with the at least one slave charging device.

Abstract: A control device includes a processor that calculates a total charge demand based on SOC information and a charge request signal of each of a plurality of electrified vehicles and performs an operation for creating, based on the calculated total charge demand, an electric power supply and demand operation plan that manages electric power for charging the electrified vehicles by a charging facility.

Abstract: A method and system for charging a battery (e.g., including but not limited to lithium-ion batteries). The method may comprise: iteratively determining a plurality of charge profiles of the battery; based on the plurality of charge profiles, iteratively determining swelling of the battery; and adjusting a charge current during a subsequent charging of the battery.

Abstract: The present invention relates to a power supply method of an electric vehicle charger in which multiple chargers are connected to the same power supply source, the power supply method comprising operations of allowing an electric vehicle to be connected to a first charger, generating a charging start signal from the first charger, receiving, by one or more other chargers, the charging start signal, generating a charging state signal from the other chargers, receiving, by the first charger, the charging state signal and determining the amount of supplied power of the first charger.

Abstract: An adaptive control method for a mobile X-ray machine includes: acquiring operating information of a battery, determining a state of the battery; if the battery is in a failure state, selecting a first control value; if the battery is not in the failure state, determining whether a residual charge of the battery is less than a low charge threshold; if the residual charge of battery is less than low charge threshold, determining the battery is in a low charge state, and selecting a second control value; and if residual charge of battery is not less than low charge threshold, determining the battery is in a normal state, and selecting a third control value; acquiring circuit parameter information of a capacitor charger, and controlling capacitor charger based on circuit parameter information and the first control value or the second control value or the third control value.

Abstract: A battery control unit includes a switching unit and a control unit. The switching unit is provided for each of a plurality of batteries connected to in series to each other, and switches a connection state in which the corresponding battery is discharged and a non-connection state in which the corresponding battery is not discharged. The control unit switches the battery to the non-connection state in order from the battery whose remaining dischargeable capacity reaches a predetermined value. Further, the control unit switches all the batteries to the connection state after the remaining dischargeable capacity of all the batteries reaches the predetermined value, and then switch the battery to the non-connection state in order from the battery determined to reach a discharge termination state.

Abstract: Provided are a non-aqueous electrolyte secondary battery excellent in reliability and productivity, a method for manufacturing the same, and a system including the non-aqueous electrolyte secondary battery. A non-aqueous electrolyte secondary battery of the present invention includes a positive electrode, a negative electrode, a separator, and a non-aqueous electrolyte. The positive electrode includes a positive electrode mixture layer in which a lithium-containing composite oxide is used as a positive electrode active material. In a charged state, the negative electrode includes an aluminum foil or an aluminum alloy foil and a Li—Al alloy formed by reaction with Li ions deintercaleted from the positive electrode. The Li—Al alloy has a Li content of 7 to 29 atomic % with respect to 100 atomic % of a total of Li and Al at the end of charge.

Abstract: Charging guidance systems and methods for charging electrified vehicles may be configured to influence a user's charging decisions in a manner that simplifies the vehicle charging experience. Exemplary charging guidance systems may be configured to coach the user to charge a traction battery pack of the vehicle at a lower level charging option as opposed to a higher level charging option. Charging at lower level charging options when certain conditions are met reduces the amount of times the vehicle is charged using more aggressive charging methodologies, thereby improving battery performance, reducing costs, and preserving the life/warranty and asset utilization of the traction battery pack over the entire usage life of electrified vehicles.

Abstract: The present disclosure generally relates to techniques for a displaying a user interface including a visual indication that an electronic device is in a protective charging mode. While the electronic device is in a charging configuration with respect to an external power source, an energy-storage component of the electronic device is charged with power supplied by the external power source. After charging the energy-storage component, a user interface is displayed. When charging of the energy-storage component is stopped before reaching a full charge level, the user interface includes a visual indication that the electronic device is in a protective charging mode in which charging of the energy-storage component is delayed based on predetermined criteria.

Abstract: An opportunistic rail charging system is disclosed for recharging power supplies on mobile robots transporting goods within an automated order fulfillment system. Individual chargers may be incorporated into each mobile robot for converting a facility line voltage from the charge rail to a voltage for which the rechargeable power supplies on each mobile robot are rated.

Abstract: A lithium ion battery including a cell formed by sequentially stacking a positive current collector, a positive active material layer, a separator, a negative active material layer, and a negative current collector, the lithium ion battery being characterized by including a frame member disposed between the positive current collector and the negative current collector to seal the positive active material layer, the separator, and the negative active material layer, the frame member having, disposed therein, an electronic component for detecting an internal condition of the cell.

Abstract: A charging and discharging control device includes one or more processors configured to determine, in response to a stop of alternate-current power supply, whether a voltage value of a storage battery, being capable of supplying power to a direct-current load, is a first threshold or less; determine, in response to a restart of the alternate-current power supply, whether a difference in voltage value between the storage battery and direct-current power output from a rectifier is a second threshold or less; disconnect between the storage battery, and the rectifier and the direct-current load when determining the voltage value of the storage battery as being the first threshold or less, and reconnect from the rectifier to the storage battery when determining the difference in voltage value between the storage battery and the direct-current power is the second threshold or less.

Abstract: Methods and systems for operating a driveline disconnect clutch actuator are provided. In one example, the driveline disconnect clutch actuator may be supplied with electric power to activate and deactivate a driveline disconnect clutch when electric power is available via a first power source. The driveline disconnect clutch actuator may be supplied with electric power to open the driveline disconnect clutch when output from the first driveline disconnect clutch is unavailable.

Abstract: The present disclosure relates to circuitry for driving a load. The circuitry comprises driver circuitry configured to generate a drive signal, based on an input signal to the driver circuitry, for driving the load, and commutator circuitry for coupling the driver circuitry to the load. The commutator circuitry is configured to alternate between commutation states in response to a level of the drive signal meeting a drive signal threshold or in response to a level of the input signal meeting a first input signal threshold. The circuitry is configured to apply an offset to the input signal when the input signal is below a second input signal threshold so as to increase a minimum level of the drive signal above the drive signal threshold or to increase a minimum level of the input signal above the first input signal threshold.

Abstract: A method and system for providing a cooperative automotive mobile charging infrastructure are described. In one embodiment, a method for providing a cooperative automotive mobile charging infrastructure includes receiving a notification indicating an availability for providing mobile charging to electric personal transport devices. Each notification includes an identification of an electrified vehicle to provide the mobile charging and a location of the electrified vehicle. The method includes receiving a request for mobile charging from a user and determining a candidate electrified vehicle that is available to provide mobile charging to the user. The method also includes providing the location of the candidate electrified vehicle to the user to provide mobile charging at the location to an electric personal transport device associated with the user.

Abstract: A carbon material for a non-aqueous secondary battery containing a graphite capable of occluding and releasing lithium ions, and having a cumulative pore volume at pore diameters in a range of 0.01 ?m to 1 ?m of 0.08 mL/g or more, a roundness, as determined by flow-type particle image analysis, of 0.88 or greater, and a pore diameter to particle diameter ratio (PD/d50 (%)) of 1.8 or less, the ratio being given by equation (1A): PD/d50 (%)=mode pore diameter (PD) in a pore diameter range of 0.01 ?m to 1 ?m in a pore distribution determined by mercury intrusion/volume-based average particle diameter (d50)×100 is provided.

Abstract: In an aspect the current disclosure is directed to an electric vehicle charger for an electric vehicle. The electric vehicle charger is comprised of an energy source, a transmitter coil electrically connected to the energy source and configured to wirelessly conduct a current in a receiver coil using induction, at least a proximity sensor configured to generate alignment data relating to an electric vehicle, and a computing device that is communicatively connected to the at least a proximity sensor. The computing device may be configured to identify the electric vehicle. Identification may include receiving and authenticating at least an identification datum, and identifying the electric vehicle using that; The computing device is configured to align the transmitter coil with the receiver coil using the alignment data. Additionally, the computing device may be configured to authorize the electric vehicle to be begin charging as a function of the authentication.

Abstract: A charging system for an electric vehicle disclosed herein may include a charger and a monitoring device. The monitoring device may be configured to output a warning message urging a person to return to a charging area in which the charger is connected to the electric vehicle when detecting the person has left the charging area after the charger started charging the electric vehicle. This charging system may be configured to output the warning message to urge the person to return to the charging area when detecting the person has left the charging area after the charger started charging the electric vehicle. Outputting such a first message may allow the electric vehicle to leave the charging area soon after charging has been completed.

Abstract: A system is disclosed which provides the ability to install a cross arm on a power pole utilizing an electrically isolated bucket which is free of all hydraulic components used by an operator in the bucket to manipulate the bucket. The system also utilizes an in-the-bucket rechargeable battery powered electric tool such as a saw, drill etc. without a need for a hydraulic electric generator in the bucket. The system includes the ability to provide communication to and from and to supply electrical power to remote portions of an electrically isolated boom, by transmitting optical power and control signals through an electrically non-conductive optical fiber.

Abstract: A control system may include a direct-current (DC) power bus for charging (e.g., trickle charging) internal energy storage elements in control devices of the control system. For example, the control devices may be motorized window treatments configured to adjust a position of a covering material to control the amount of daylight entering a space. The system may include a DC power supply that may generate a DC voltage on the DC power bus. For example, the DC power bus may extend from the DC power supply around the perimeter of a floor of the building and may be connected to all of the motorized window treatments on the floor (e.g., in a daisy-chain configuration). Wiring the DC power bus in such a manner may dramatically reduce the installation labor and wiring costs of an installation, as well as decreasing the chance of a miswire.

Abstract: In a battery monitoring system including a plurality of battery modules each including one or more cells, the battery modules are connected in series to each other. The battery monitoring system monitors the state of each cell based on the voltage value of the cell and the current value of the battery modules. A current detection unit detects the current value. Each voltage detection unit is associated with the corresponding one of the battery modules and detects the voltage value. Each slave unit is associated with the corresponding one of the battery modules, and wirelessly transmits information including synchronous current and voltage values detected by the current detection unit and the voltage detection unit. A master unit receives the information transmitted from the slave units. A central monitoring unit receives the information received by the master unit.

Abstract: A battery powered welding system is provided. In one welding system a battery powered welder includes control circuitry configured to control a welding power output converted from power from an external battery power source. The battery powered welder also includes a wire drive assembly coupled to the control circuitry and configured to feed a welding wire using power from the external battery power source. The battery powered welder includes a case integrally supporting and enclosing the control circuitry and the wire drive assembly. The case is not configured to enclose the external battery power source.

Abstract: An example operation includes one or more of maneuvering, by a Mobile Energy Storage Unit (MESU), to a transport that is stationary for an amount of time, that is not currently being charged, that is at a distance between the transport and the MESU and that is within a timeframe for the MESU to reach the transport, and retrieving, by MESU, a minimum amount of energy from the transport.

Abstract: A method for determining a minimum state of charge for an energy storage means of a vehicle can include: determining a routine of use of charge of the energy storage means; determining a user requirement for future driving of the vehicle; predicting a reduction in the state of charge of the energy storage means associated with the user requirement in dependence on the determined routine; determining a minimum state of charge for the energy storage means for enabling the user requirement to be satisfied in dependence on the predicted reduction; and providing an output to the user indicative of a time requirement for increasing the state of charge of the energy storage means to a value at or above the minimum state of charge.

Abstract: A power-transmitting unit starts transmitting power to a power-receiving unit in a vehicle if (1-1) operation information represents a parking operation of the vehicle and/or (2-1) intention information represents that a user of the vehicle intends to get off the vehicle, and (3) authentication information represents that the user of the vehicle is a registered user. The power-transmitting unit stops transmitting the power to the power-receiving unit if (1-2) the operation information represents a start operation of running of the vehicle and/or (2-2) the intention information represents that the user of the vehicle intends to get in the vehicle, and (3) the authentication information represents that the user of the vehicle is the registered user.

Abstract: A storage and charging station system for mobile electronic devices is described. The storage and charging station system includes a support tower structure including shelves for storing the mobile electronic devices during charging, a support device coupled to the support tower structure, a grid system on one side of the support tower structure, the grid system for mounting various accessories, a wire management system positioned adjacent to each of the shelves, a cable management system coupled to one side of the support tower structure, and a power distribution unit coupled to the support tower structure.

Abstract: A “Versatile Power Stack Unit” (VPSU) for controlling electrical devices such as motors for electric vehicles is disclosed. The VPSU uses a DC/DC buck-boost converter that generates output voltage. By varying the voltage according to need, the system can maintain a Pulse-Width Modulation duty cycle of 50% without introducing any ripple current or voltage into the batteries or system, while minimizing losses due to internal resistance. Any number of VPSUs can be connected one to the other in order to provide the voltage and current needed to power the electrical device. Not only does the VPSU minimize ripple current and losses due to internal resistance, but it enables recharging at low voltage and according to the needs of small numbers of batteries with minimal temperature rise during the charging, thereby extending battery lifetime and improving battery performance.

Abstract: The present disclosure provides methods and systems for reducing noise induced in one or more components in a hearing aid. The present disclosure provides methods for reducing noise induced in telecoils.

Abstract: A power reception control method for a power storage element controls element-receiving electric power received by the power storage element in an electric power system for supplying electric energy to a load group including plural power storage elements. The power reception control method acquires differential electric power by subtracting a current value of total transmitted electric power from a maximum value of the total transmitted electric power that is an available amount to be supplied to the entire load group via an electric power supply base point, calculates a degree of priority of the power storage element in accordance with a numerical value indicating a demand of a user, multiplies the differential electric power by the degree of priority to calculate element differential electric power, and adds the element differential electric power to the previous element-receiving electric power so as to update the element-receiving electric power.

Abstract: A battery control unit includes a switching unit, a system controller, and a control unit. The switching unit switches between a connection state in which the corresponding battery is discharged and a non-connection state in which the corresponding battery is not discharged. The system controller limits a discharge current flowing through the battery in the connection state so as not to exceed a minimum discharge current limitation value that is smallest among discharge current limitation values. The control unit switches to the non-connection state in order from the battery having the minimum discharge current limitation value before the discharge current limitation unit limits the discharge current. Further, the control unit switches all the batteries to the connection state after the batteries in the connection state becomes one, and then switch the battery to the non-connection state in order from the battery determined to reach a discharge termination state.