Abstract: The battery pack includes a battery cell for supplying electric power to an external device connected thereto, a temperature sensor for sensing a temperature of a place on which the temperature sensor is arranged, a switch member for making and breaking an electric path between the external device and the battery cell; and a controller configured to control the switch member to turn on and off according to the temperature sensed by the temperature sense. The temperature sensor is arranged on a position between the battery cell and the switch member so as to be affected by the temperatures of both of the battery cell and the switch member.

Abstract: An electric tool adaptor is configured to be disposed between an electric tool and a battery pack and attached detachably with respect to the electric tool and the battery pack. This adaptor includes a DC-DC converter configured to increase or reduce a voltage of the battery pack to convert the voltage to a drive voltage of the electric tool and supply the drive voltage to the electric tool.

Abstract: A charger includes an output circuit unit to output a charging current to a secondary battery, a voltage detection unit to detect a voltage of the secondary battery, and a control unit to control the output circuit unit, whereby constant current charging and constant voltage charging are performed. The control unit decreases a constant current value of the charging current by stages during the constant current charging and determines that the secondary battery has deteriorated by using a first voltage drop value of the secondary battery occurring upon first conversion and a second voltage drop value of the secondary battery occurring upon second conversion.

Abstract: An impact power tool includes an impact mechanism for applying a striking impact to an output shaft by using an output power of a motor. A strike detection unit detects the striking impact applied by the impact mechanism to obtain a striking timing and a striking speed detection unit calculates a striking speed from the striking timing obtained by the strike detection unit and a rotation angle of the motor obtained by a rotation angle detection unit. A control unit counts the number of striking impact detected by the strike detection unit and stops the motor if the number of striking impact reaches a predetermined strike number. The control unit is designed to correct the predetermined strike number when the striking speed obtained in the striking speed detection unit is equal to or lower than a specified striking speed.

Abstract: An electric power tool is included in a plurality of types of electric power tools. The plurality of types of electric power tools comprise a plurality of types of battery packs having different rated output voltages and a plurality of types of tool bodies, the housings of which are equipped with an attached part on which each of the battery packs is mounted in a freely removable manner. The attached part possessed by the plurality of types of tool bodies equipped with motors having different voltage characteristics is formed so as to be able to mount an arbitrary one of the plurality of types of battery packs having different rated output voltages. This makes it possible to widen the range of available battery packs and enhance convenience.

Abstract: The battery pack includes a battery cell for supplying electric power to an external device connected thereto, a temperature sensor for sensing a temperature of a place on which the temperature sensor is arranged, a switch member for making and breaking an electric path between the external device and the battery cell; and a controller configured to control the switch member to turn on and off according to the temperature sensed by the temperature sense. The temperature sensor is arranged on a position between the battery cell and the switch member so as to be affected by the temperatures of both of the battery cell and the switch member.

Abstract: An electric tool adaptor is configured to be disposed between an electric tool and a battery pack and attached detachably with respect to the electric tool and the battery pack. This adaptor includes a DC-DC converter configured to increase or reduce a voltage of the battery pack to convert the voltage to a drive voltage of the electric tool and supply the drive voltage to the electric tool.

Abstract: A charging circuit includes a battery pack provided with one or more secondary batteries and a battery charger for charging the secondary batteries, the battery pack being detachably attachable to the battery charger. The charging circuit further includes a control unit for performing a charging control, a monitoring unit for detecting charged voltage of the secondary batteries to determine completion of charging, a storage unit storing charging data for use in the charging control of the control unit and determination of the charging completion of the monitoring unit and a changing unit for changing the charging data. The monitoring unit and the storage unit are arranged in the battery pack, and the changing unit and the control unit are arranged in the battery charger.

Abstract: A charger includes an output circuit unit to output a charging current to a secondary battery, a voltage detection unit to detect a voltage of the secondary battery, and a control unit to control the output circuit unit, whereby constant current charging and constant voltage charging are performed. The control unit decreases a constant current value of the charging current by stages during the constant current charging and determines that the secondary battery has deteriorated by using a first voltage drop value of the secondary battery occurring upon first conversion and a second voltage drop value of the secondary battery occurring upon second conversion.

Abstract: A battery pack which is detachably connected to a charger and charged by connecting thereto, includes a battery assembly including a plurality of secondary batteries serially connected; a pair of power terminals connected to a negative and a positive electrode of the battery assembly, respectively; a control circuit adapted to individually detect voltages across respective secondary batteries and output a charge control signal to the charger when the detected voltages exceed a predetermined value; a signal terminal adapted to output the charge control signal to the charger; and a temperature measurement element for detecting a temperature of the battery assembly. Further, the control circuit changes the predetermined value to be compared with the detected voltages based on the detected temperature of the temperature measurement element.

Abstract: An electric power tool is included in a plurality of types of electric power tools. The plurality of types of electric power tools comprise a plurality of types of battery packs having different rated output voltages and a plurality of types of tool bodies, the housings of which are equipped with an attached part on which each of the battery packs is mounted in a freely removable manner. The attached part possessed by the plurality of types of tool bodies equipped with motors having different voltage characteristics is formed so as to be able to mount an arbitrary one of the plurality of types of battery packs having different rated output voltages. This makes it possible to widen the range of available battery packs and enhance convenience.

Abstract: A charging controller connected to at least one of secondary cells and detachably connected to a charger or a cell driver, the charging controller including: a charging amount control circuit detecting a cell voltage of each secondary cell and outputting a charging control signal for instructing the charger to reduce a charging current when the detected cell voltage exceeds the target voltage; and a protection circuit detecting a cell voltage of each secondary cell and cutting off a current path from the charger to the secondary cell when the detected cell voltage exceeds the upper limit voltage, the protection circuit operating by using the secondary cell as a power source while at least the charger is not connected. In the charging controller, while neither the charger nor the cell driver are connected, the charging amount control circuit does not operate.

Abstract: A battery pack includes cylindrical columnar battery cells arranged at least in two rows and two columns along vertical and horizontal directions orthogonal to center axes of the battery cells. Each of the battery cells includes an electrode terminal formed in one end portion thereof. The battery pack further includes a connector plate to which the electrode terminals of four vertically and horizontally adjoining battery cells are joined. The connector plate is arranged to parallel connect each pair of the battery cells adjoining in the same direction to form battery cell blocks. The connector plate is configured to serially connect the battery cell blocks. The center axes of the battery cells are positioned at vertexes of a parallelogram when the vertically and horizontally adjoining battery cells are seen at one end side thereof. The connector plate has a contour conforming to respective sides of the parallelogram.

Abstract: A charging circuit includes a battery pack provided with one or more secondary batteries and a battery charger for charging the secondary batteries, the battery pack being detachably attachable to the battery charger. The charging circuit further includes a control unit for performing a charging control, a monitoring unit for detecting charged voltage of the secondary batteries to determine completion of charging, a storage unit storing charging data for use in the charging control of the control unit and determination of the charging completion of the monitoring unit and a changing unit for changing the charging data. The monitoring unit and the storage unit are arranged in the battery pack, and the changing unit and the control unit are arranged in the battery charger.

Abstract: A charging device for charging battery packs includes charging terminals including a first charging terminal to be connected to an electrode of a first battery pack and a second charging terminal to be connected to an electrode of a second battery pack. Here, the first and the second battery pack are different in kind. Further, the charging device includes a conversion unit for supplying electricity to the first charging terminal when the electrode of the first battery pack is connected to the first charging terminal and supplying electricity to the second charging terminal when the electrode of the second battery pack is connected to the second charging terminal.

Abstract: A battery pack which is detachably connected to a charger and charged by connecting thereto, includes a battery assembly including a plurality of secondary batteries serially connected; a pair of power terminals connected to a negative and a positive electrode of the battery assembly, respectively; a control circuit adapted to individually detect voltages across respective secondary batteries and output a charge control signal to the charger when the detected voltages exceed a predetermined value; a signal terminal adapted to output the charge control signal to the charger; and a temperature measurement element for detecting a temperature of the battery assembly. Further, the control circuit changes the predetermined value to be compared with the detected voltages based on the detected temperature of the temperature measurement element.

Abstract: A charging controller connected to at least one of secondary cells and detachably connected to a charger or a cell driver, the charging controller including: a charging amount control circuit detecting a cell voltage of each secondary cell and outputting a charging control signal for instructing the charger to reduce a charging current when the detected cell voltage exceeds the target voltage; and a protection circuit detecting a cell voltage of each secondary cell and cutting off a current path from the charger to the secondary cell when the detected cell voltage exceeds the upper limit voltage, the protection circuit operating by using the secondary cell as a power source while at least the charger is not connected. In the charging controller, while neither the charger nor the cell driver are connected, the charging amount control circuit does not operate.

Abstract: A charging apparatus includes a battery pack, which includes a cell voltage detection unit outputting a signal if a detected cell voltage is not smaller than V1, and a temperature sensor detecting a temperature of the battery pack; and a charger, which includes a charging control circuit and a pack voltage detection unit detecting a voltage across two terminals of the battery pack. If the detected temperature from the temperature sensor exceeds 0° C., the charging control circuit switches to a constant voltage charging when the signal from the cell voltage detection unit is received; and if otherwise, the charging control unit switches to the constant voltage charging when receiving the signal or the detected pack voltage exceeds V2, whichever occurs first.

Abstract: An impact power tool includes an impact mechanism for applying a striking impact to an output shaft by using an output power of a motor. A strike detection unit detects the striking impact applied by the impact mechanism to obtain a striking timing and a striking speed detection unit calculates a striking speed from the striking timing obtained by the strike detection unit and a rotation angle of the motor obtained by a rotation angle detection unit. A control unit counts the number of striking impact detected by the strike detection unit and stops the motor if the number of striking impact reaches a predetermined strike number. The control unit is designed to correct the predetermined strike number when the striking speed obtained in the striking speed detection unit is equal to or lower than a specified striking speed.

Abstract: A charging device for charging battery packs includes charging terminals including a first charging terminal to be connected to an electrode of a first battery pack and a second charging terminal to be connected to an electrode of a second battery pack. Here, the first and the second battery pack are different in kind. Further, the charging device includes a conversion unit for supplying electricity to the first charging terminal when the electrode of the first battery pack is connected to the first charging terminal and supplying electricity to the second charging terminal when the electrode of the second battery pack is connected to the second charging terminal.