To reduce standby time during charging, a charging device includes a housing on which a battery pack is detachably mountable, a control board, and a cooling fan. The battery pack is formed with a vent hole. The housing is formed with a ventilation opening configured to face the vent hole. The cooling fan is configured to flow an air passing through the control board and the ventilation opening, and is configured to work even in a state where the battery pack is detached.

A battery pack contains a plurality of battery cells that includes a first battery cell and a second battery cell; a first thermistor disposed closest to the first battery cell among the battery cells; a second thermistor disposed closest to the second battery cell among the battery cells. A case of the battery pack holds the battery cells, the first thermistor, and the second thermistor. The first battery cell is disposed such that at least one of the other battery cells is interposed between the first battery cell and a wall surface of the case in a direction orthogonal to a longitudinal direction of the first battery cell. The second battery cell is disposed such that none of the other battery cells is interposed between the second battery cell and the wall surface of the case in a direction orthogonal to a longitudinal direction of the second battery cell.

A battery pack contains a plurality of battery cells that includes a first battery cell and a second battery cell; a first thermistor disposed closest to the first battery cell among the battery cells; a second thermistor disposed closest to the second battery cell among the battery cells. A case of the battery pack holds the battery cells, the first thermistor, and the second thermistor. The first battery cell is disposed such that at least one of the other battery cells is interposed between the first battery cell and a wall surface of the case in a direction orthogonal to a longitudinal direction of the first battery cell. The second battery cell is disposed such that none of the other battery cells is interposed between the second battery cell and the wall surface of the case in a direction orthogonal to a longitudinal direction of the second battery cell.

A hand-held power tool, in particular a hammer drill or a combination hammer, is disclosed. The hand-held power tool includes a tool housing which has a receiving recess designed to replaceably receive a storage battery or a power supply unit. The hand-held power tool has an electric drive motor with a cooling fan. The tool housing has a first vent portion which is located in the receiving recess and through which a volume flow generated by the cooling fan can be guided.

A hand-held power tool, in particular a hammer drill or a combination hammer, is disclosed. The hand-held power tool includes a tool housing which has a receiving recess designed to replaceably receive a storage battery or a power supply unit. The hand-held power tool has an electric drive motor with a cooling fan. The tool housing has a first vent portion which is located in the receiving recess and through which a volume flow generated by the cooling fan can be guided.

A battery pack may include a plurality of battery cells, a cell holder which holds the plurality of battery cells, and a casing which houses the cell holder. Each of the plurality of battery cells may have a substantially cylindrical shape and have a longitudinal direction in a front-rear direction. The plurality of battery cells may be arranged side by side in a left-right direction and an up-down direction. The cell holder may include an inner air supply opening which is defined in a surface facing the plurality of battery cells in a first direction orthogonal to the front-rear direction and an inner exhaust opening which is defined in a surface facing the plurality of battery cells in the front-rear direction. The casing may include an outer air supply opening and an outer exhaust opening which is defined in a surface facing the inner exhaust opening of the cell holder.

A rechargeable battery, particularly a rechargeable tool battery, includes at least one cell block which has at least one heat dissipation element, which is provided to dissipate heat from the cell block, and a rechargeable battery housing, which has at least one heat radiation element, which is provided at least to radiate the heat dissipated by the heat dissipation element to the surroundings. It is provided that the heat dissipation element and the heat radiation element are formed as components configured separately from each other.

A rechargeable battery, particularly a rechargeable tool battery, includes at least one cell block which has at least one heat dissipation element, which is provided to dissipate heat from the cell block, and a rechargeable battery housing, which has at least one heat radiation element, which is provided at least to radiate the heat dissipated by the heat dissipation element to the surroundings. It is provided that the heat dissipation element and the heat radiation element are formed as components configured separately from each other.

Process for controlling a battery including energy storage cells, a controlling device, a sensor for detecting mechanical parameter or electrical parameter, a safety device, an interface for connecting the battery to an external device and electrical wiring. The process includes detecting parameter and eliminating the provision of electric energy from the energy storage cells, if a detected parameter reaches a predetermined threshold value. Battery including a energy storage cell, a controlling device, a sensor for detecting mechanical parameter or electrical parameter, an interface for connecting the battery to an external device, electrical wiring for transmitting electric energy between the at least one battery cell and the external device. The battery includes a safety device for eliminating the provision of electric energy from the energy storage cells, if a parameter detected by the sensor reaches a predetermined threshold value. System including a battery and an external device connectable to the battery.

Disclosed is a secondary battery pack including a plurality of cylindrical battery cells with improved cooling efficiency. The secondary battery pack includes a plurality of cylindrical battery cells having electrode terminals formed at both ends thereof; a pack case having an accommodation portion formed to accommodate the plurality of cylindrical battery cells therein and at least one exposing portion perforated from an inside to an outside thereof; at least one heat dissipation plate configured in the form of a metal plate and located at the exposing portion of the pack case so that at least a portion thereof is exposed out through the exposing portion of the pack case; and a heat transfer pad having a thermally conductive material in a solid state and interposed between the plurality of cylindrical battery cells and the heat dissipation plate.