Abstract: An electric device in one aspect of the present disclosure comprises a connector, a power supply unit, a connection-detection unit, and a control unit. The control unit is configured to control electric power supplied to the power supply unit from a battery so as to increase electric power supplied to the power supply unit when the connection-detection unit detects that an external device is connected to the connector.

Abstract: An electric device in one aspect of the present disclosure comprises a connector, a power supply unit, a connection-detection unit, and a control unit. The control unit is configured to control electric power supplied to the power supply unit from a battery so as to increase electric power supplied to the power supply unit when the connection-detection unit detects that an external device is connected to the connector.

Abstract: An electric power tool includes a tool portion, a fuel cell, a power drive source, and a water-holding unit. The water-holding unit holds a reaction water produced in the fuel cell by oxidation reaction between a fuel and an oxidizing agent.

Abstract: A system for charging a power tool battery includes a charging device capable of charging a battery, a memory device capable of storing data of a plurality of sound patterns, a selecting device capable of selecting a sound pattern data from the plurality of sound patterns, and a sound generating device capable of generating a sound based on the selected sound pattern data when the charging operation of the battery by the charging device has been completed.

Abstract: A system for charging a power tool battery includes a charging device capable of charging a battery, a memory device capable of storing data of a plurality of sound patterns, a selecting device capable of selecting a sound pattern data from the plurality of sound patterns, and a sound generating device capable of generating a sound based on the selected sound pattern data when the charging operation of the battery by the charging device has been completed.

Abstract: A battery charging system is disclosed for charging two different types of battery packs, a known three terminal type including batteries and a thermostat switch, and a newer four terminal type further including a thermistor for sensing battery temperature. A charging control circuit stops charging current to the battery pack when a contact of the thermostat switch is open or when the thermistor detects a temperature above a predetermined temperature. If either the thermostat switch or the thermistor fail to properly operate, charging current to the battery pack is stopped securely to avoid damaging batteries.