Electrical apparatus

An electrical apparatus comprising:

• an electrical apparatus main body including:
• a load,
• a manipulation switch for operating the load,
• a power receiving electrode for receiving an electric power,
• a main body control unit for controlling the electric power supplied from the power receiving electrode to the load in response to a manipulation of the manipulation switch,
• a signal generation unit for generating an on-manipulation signal to indicate that the manipulation switch is switched on if the manipulation switch is switched on, and
• a main body signal electrode for outputting the on-manipulation signal generated by the signal generation unit;
• and
• a battery pack including:
• a battery,
• a power supplying electrode for supplying an electric power from the battery to the power receiving electrode,
• a battery control unit for controlling the electric power supplied from the battery to the power supplying electrode to suppress a performance deterioration of the battery,
• a battery signal electrode for receiving the on-manipulation signal from the main body signal electrode, and
• a power supplying unit for starting a power supply from the battery to the battery control unit when the battery signal electrode receives the on-manipulation signal, wherein the battery pack further includes:
• a detection unit for detecting a state of the battery, and
• wherein the signal generation unit further generates an off-manipulation signal to indicate that the manipulation switch is switched off if the manipulation switch is switched off,
• the main body signal electrode further outputs the off-manipulation signal generated by the signal generation unit,
• the battery signal electrode further receives the off-manipulation signal from the main body signal electrode, and
• the battery control unit adjusts a period of time for which the electric power is supplied from the power supplying unit based on the state of the battery detected by the detection unit when the battery signal electrode receives the off-manipulation signal.