Patent ID: 7764478

Claim:
A power supply control system comprising: a power supply circuit configured to supply a DC voltage output from a power supply unit which detachably holds a battery to a load circuit; a first switch circuit configured to set a power supply line which connects the power supply unit and said power supply circuit to one of a connected state and a non-connected state; a first control unit configured to operate in one of a normal mode and a sleep mode in which a consumption current is smaller than in the normal mode, and to detect a magnitude of a current flowing into said first switch circuit and control an operation of said first switch circuit based on the detected magnitude of the current while operating in the normal mode; an opening-closing state detection unit configured to detect an opening-closing state of a battery lid provided to the power supply unit; and a second control unit configured to control an operation of said first control unit based on the detection result obtained by said opening-closing state detection unit, wherein if said opening-closing state detection unit detects that the opening-closing state of the battery lid is an opening state, said second control unit operates said first control unit in the normal mode to detect the magnitude of the current flowing into said first switch circuit.