Power supply control apparatus

A power supply control apparatus (2) for controlling a power supply unit (1) including a battery and a load (3) is provided. The power supply control apparatus (2) includes a main relay (6) and a ground relay (7), a pre-charge relay (8), an inrush current limiting resistor (9), a first relay control section (13), and a time measurement section (13). The main relay (6) and the ground relay (7) are connected between the battery and the load (3). The pre-charge relay (8) is connected in parallel with one of the main relay (6) and the ground relay (7). The inrush current limiting resistor (9) is connected in series with the pre-charge relay (8), and limits an inrush current from the battery to the load (3). The first relay control section (13) temporarily turns ON the pre-charge relay (8) and turns ON the main relay (6) and the ground relay (7) upon receiving a power supply connection request from the outside, and turns OFF the main relay (6) and the ground relay (7) upon receiving a power supply interruption request from the outside. The time measurement section (13) chooses a time point in the period from when the pre-charge relay (8) is turned ON to when it is turned OFF, and measures the elapsed time from the chosen time point. Before the elapsed time measured by the time measurement section (13) reaches a predetermined reference period, the first relay control section (13) does not turn OFF the main relay (6) and the ground relay (7), but maintains the relays ON, even when receiving the power supply interruption request.