Abstract: Hysteresis is stored when charge has been started in a condition in which the battery temperature is high and the capacity is large; upon judging whether such charge has been frequently performed, if it has been judged that the frequency is high, a pattern 4 is selected in which charge is performed by decreasing the current value; with this arrangement, batteries may be used for a long period by decreasing the charge current even if the user should repeatedly perform charge in conditions in which the temperature is high and the residue capacity large through which the life of batteries is shortened.

Abstract: An operation switch device for use with a lawnmower includes a switch and a first operation member operably movable between an "ON" position and an "OFF" position. A second operation member is mounted on the first operation and is positionable in a first position where the switch is turned on and a second position where the switch is held off when the first operation member is in the "ON" position and the "OFF" position, respectively. A restraining member in a restraining position is operable to prevent the second operation member from moving from the second position to the first position. The restraining member in a releasing position is operable to permit the second operation member to move from the second position to the first position.

Abstract: A battery charging device for use with a battery driven tool has a power source circuit and an interlock switch provided in the power source circuit. The battery charging device includes an operation panel having an operation key insertion opening and a charging plug insertion opening formed therein. A slide plate is movable relative to the operation panel between an ON position for turning on the interlock switch and for substantially closing the charging plug insertion opening, and an OFF position for turning off the interlock switch and for substantially opening the charging plug insertion opening. An operation key is adapted to be connected to the slide plate by means of a connecting mechanism. The operation key is permitted to be connected to the slide plate through the operation key insertion opening by means of the connecting mechanism when the slide plate is in the OFF position.