An electric energy storage device which includes four energy units with a substantially same voltage value is provided. Each energy unit is provided with a positive electrode and a negative electrode. The electric energy storage device comprises a socket with eight independently arranged electrode terminals that are connected with the four energy units. The disclosure also provides an electric tool system using the electric energy storage device. The electric tool is provided with plugs that may be connected with the four energy units in different states, allowing the electric energy storage device to output multiple voltages.

A charge-discharge circuit and an electric device. The charge-discharge circuit includes a power supply module, a first drive assembly, a second drive assembly, and a first switch module, where the first drive assembly and the second drive assembly are connected in parallel between a positive terminal and a negative terminal of the power supply module; and a terminal of the first switch module is connected to the first drive assembly, and another terminal of the first switch module is connected to the second drive assembly.

Examples described herein provide a method that includes receiving, at a vehicle comprising a first battery pack and a second battery pack, at least one of a first electric charge from a first charging station via a first charging port or a second electric charge from a second charging station via a second charging port. The method further includes determining, by a controller of the vehicle, a charging mode of the vehicle. The charging mode is selected from a group consisting of a dynamic balancing during independent multi-port charging mode, a dynamic balancing during independent port charging mode, or a dynamic balancing during parallel charging mode. The method further includes configuring, by the controller of the vehicle, a plurality of switches of a rechargeable energy storage system of the vehicle based at least in part on the determined charging mode.

A battery apparatus, including a battery switch that allows or blocks an electrical connection between a first battery and a second battery, a first power conversion module that performs power conversion between the first battery and an intermediary capacitor, a second power conversion module that performs power conversion between the second battery and the intermediary capacitor, and a processor configured to control the first and second power conversion modules so that the first and second batteries are complementarily charged and discharged via the intermediary capacitor in an open state of the battery switch and obtains characteristic parameters of the first and second batteries after complementarily charging and discharging the first and second batteries is completed.

A power supply system includes a first battery, a second battery, a voltage converter connected to a power generator or an external power supply, and a series-parallel switching circuit configured to switch connection of the first and second batteries between series connection and parallel connection by turning on and off a plurality of relays. The power supply system performs charge equalization control, namely control of alternatingly performing a first battery charging process and a state-of-charge equalization process. The first battery charging process is a process of charging the first battery by turning on and off the relays. The state-of-charge equalization process is a process of equalizing the state of charge of the first battery and the state of charge of the second battery. The power from the power generator or the external power supply is supplied to the auxiliary equipment or the auxiliary battery during the state-of-charge equalization process.

A secondary battery system is a secondary battery system including a battery bank including a battery rack including a plurality of battery cells connected in series and a power converter for charging and discharging a power system by one or a plurality of the battery racks connected in parallel, the secondary battery system includes a switch that enables the battery rack included in the battery bank to be switched to a power converter of another battery bank; and a controller that monitors a deterioration rate or an age of use of the battery rack and controls the power converter and the switch, in which the controller instructs the switch about a power converter to be connected based on the deterioration rate or the age of use of the battery rack.

The electric power system includes a first power storage device, a second power storage device where a second negative terminal is connected to the negative-side line, a series relay provided in a series line connecting the first negative terminal of the first power storage device and the second positive terminal of the second power storage device, a power storage system having a parallel relay provided in a parallel line connecting the first negative terminal and the negative-side line, a motor, first and second inverter units, and a changeover switch provided between the first and second inverter units of the positive-side line. The first inverter unit includes a three-level inverter having a first upper arm and a second lower arm of a third phase, and an intermediate potential switch of first, second capacitor, and three phases. The second positive terminal is connected to connection points of the first and second capacitors.

A unique system for the implementation of a multi cell battery pack whereby the individual cells are organized in different configurations for discharge or charging operation is presented. Battery pack discharge operation utilizes a series (stacked) configuration capable of producing a high output voltage necessary for the application. In contrast, charging operation configures the individual cells into a parallel (single layer) organization offering a simple fast charge operation provided by natural current sharing of the cells. Switch over between the two configurations is achieved using switching array implemented by low-cost N-channel MOSFET devices. Usage of dual modes for battery charge/discharge operation offers a simplified implementation with the highest performance. An application is also described where the present invention is used as a compatible replacement of a standard 12V lead acid automotive battery.

One aspect of an invention is a power receiving apparatus, configured to be able to receive electric power from a plurality of battery units each including a processor configured to control a power feeding function, the power receiving apparatus comprising a plurality of connection portions capable of electrically connecting the plurality of battery units, wherein the plurality of connection portions are configured such that voltages supplied to the plurality of processors of the plurality of battery units have different values when the plurality of battery units are electrically connected to the connection portions

A series-parallel battery system includes: a switch (1), a series-parallel battery (2) and a charge and discharge management circuit (3). The series-parallel battery (2) includes a battery combination management circuit (23) and at least two batteries connected to each other. The battery combination management circuit (23) is connected to the batteries. One battery in the series-parallel battery (2) includes a second battery cell (22) and a third protection circuit (26). Other batteries in the series-parallel battery (2) include a first battery cell (21), a first protection circuit (24) and a second protection circuit (25). The switch (1) is connected to the batteries. The charge and discharge management circuit (3) is connected to the battery combination management circuit (23) and used for controlling states of the switch (1), of the first protection circuit (24), and of the second protection circuit (25), so as to adjust a connection mode of the batteries.