ELECTRIC POWER SUPPLY SYSTEM

An electric power supply system includes an electric power storage device, a first relay provided between a first electric power line pair connected to the electric power storage device and a second electric power line pair connected to electrical equipment, a bidirectional electric power conversion device that is configured to be able to bidirectionally convert electric power between the second electric power line pair and an electric power facility outside of a vehicle, a first capacitor provided between the second electric power line pair, and a control device configured to execute first precharge processing of charging the first capacitor prior to turning on the first relay. The bidirectional electric power conversion device includes a switching device. The control device starts the first precharge processing when the bidirectional electric power conversion device is activated.