A power tool system includes a first and second power tools with different rated-voltages and a battery pack supplying power to the corresponding power tool. The battery pack has a battery module with two battery cell groups and a female connector having four conductive terminals respectively connected to positive and negative electrodes of two battery cell groups. The female connector has a converter switching the connection of two battery cell groups between parallel connected state to isolated connected state through connecting or disconnecting two conductive terminals with same polarity together. The first power tool includes a first male connector connected to the female connector to connect two battery cell groups in series through connecting two conductive terminals with different polarities together. The second power tool has a second male connector coupled to the female connector to connect two battery cell groups in parallel through connecting two conductive terminals with same polarity together.

A portable electronic device with a battery switching function is provided. The portable electronic device has two battery switching assemblies corresponding to each battery. Each battery switching assembly has a primary fastener and a secondary fastener corresponding to each other. When the primary fastener is engaged with the secondary fastener, the secondary fastener engages with the corresponding battery so that the battery cannot be detached from the casing of the portable electronic device. When the primary fastener and the secondary fastener are disengaged, the Hall sensor corresponding to the primary fastener sends a signal to a control unit. Then the control unit turns off the power supply of the corresponding battery and switches to another battery to supply power, or closes a specific application to reduce power consumption.

A portable electronic device with a battery switching function is provided. The portable electronic device has two battery switching assemblies corresponding to each battery. Each battery switching assembly has a primary fastener and a secondary fastener corresponding to each other. When the primary fastener is engaged with the secondary fastener, the secondary fastener engages with the corresponding battery so that the battery cannot be detached from the casing of the portable electronic device. When the primary fastener and the secondary fastener are disengaged, the Hall sensor corresponding to the primary fastener sends a signal to a control unit. Then the control unit turns off the power supply of the corresponding battery and switches to another battery to supply power, or closes a specific application to reduce power consumption.

A battery pack includes a housing and electrochemical cells disposed in the housing. The housing includes a container and a lid that closes an open end of the container. The container has a base, an outer wall the surrounds the base, and a first and a second inner wall disposed inside the outer wall. The first inner wall extends between, and is fixed to, a first portion and a third portion of the outer wall, and is spaced apart from a second portion and a fourth portion of the outer wall. The second inner wall extends between the first portion and the third portion, and is disposed between the first inner wall and the fourth portion. The second inner wall is movable relative to the outer wall such that spacing of the second inner wall from the first inner wall can be changed.

A multi-voltage storage system for an at least partly electrically driven vehicle includes a first storage module and a second storage module having an identical rated voltage for storing electrical energy, wherein on-board consumers are connected to the second storage module at least with priority during a charging process, a heating apparatus for heating the storage modules, a switch unit which is designed to connect the first storage module and the second storage module in series for a charging process and in parallel for driving the vehicle, and a control unit, which is firstly designed to control the switch unit before and/or during a charging process such that the parallel connection of the first storage module and the second storage module is eliminated, and which is secondly designed, after elimination of the parallel connection, to activate the heating apparatus before and/or during the charging process.

A multi-voltage storage system for an at least partly electrically driven vehicle includes a first storage module and a second storage module having an identical rated voltage for storing electrical energy, wherein on-board consumers are connected to the second storage module at least with priority during a charging process, a heating apparatus for heating the storage modules, a switch unit which is designed to connect the first storage module and the second storage module in series for a charging process and in parallel for driving the vehicle, and a control unit, which is firstly designed to control the switch unit before and/or during a charging process such that the parallel connection of the first storage module and the second storage module is eliminated, and which is secondly designed, after elimination of the parallel connection, to activate the heating apparatus before and/or during the charging process.

The invention relates to a power tool and battery pack assembly including a battery pack for connection with the power tool to provide power for the operation of the power tool when connected thereto. The battery pack includes a plurality of power cells and connection means are provided to allow the selective supply of power at least a first or second voltage level to the power tool from the battery pack.

The invention relates to a power tool and battery pack assembly including a battery pack for connection with the power tool to provide power for the operation of the power tool when connected thereto. The battery pack includes a plurality of power cells and connection means are provided to allow the selective supply of power at least a first or second voltage level to the power tool from the battery pack.

A battery system includes a plurality of battery cell packs arranged in layers selectively connected in series and parallel by a control system controlling a plurality of switches. Each of the battery cell packs includes a plurality of battery cells. A plurality of first switches and a plurality of second switches are controlled by a control system to connect the battery cell packs in response to a desired current output of the battery system and/or a desired voltage output of the battery system irrespective of individual battery cell or battery cell pack voltages or currents associated with state of charge or operational performance. The control system controls the switches to selectively connect the battery cell pack(s) to the output connections in parallel and/or series to provide redundancy and reduce output voltage/current fluctuation otherwise associated with state of charge or underperforming battery cells/packs.

The disclosure provides an electric energy storage device which includes four energy units with a substantially same voltage value. 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.