Patent ID: 8041966

Claim:
An electric power supply system comprising: a first terminal that electric power is supplied thereto from a first power supply to operate, the first terminal having an output; a device connected to the output of the first terminal; a second terminal that is connected to the first terminal and that electric power is supplied thereto from a second power supply to operate; and a controller that controls electric power supply so as to supply electric power from the first terminal to the second terminal, and from the second terminal to the first terminal, based on an operation state of the first terminal, the controller having a judgment section configured to determine if power sharing is necessary based on consumption of power by motors, solenoids, sensors and heaters of the device connected to the first terminal, wherein the controller is located within the device connected to the output of the first terminal, and the device connected to the first terminal is in a sleep mode, and a device connected to the second terminal is in a standby mode.