POWER SUPPLY CONTROL DEVICE AND POWER SUPPLY CONTROL METHOD

A controller of a power supply control is configured to: in response to a failure of a main power supply being detected, execute a fail-safe control in which a connector is interrupted and electric power from a backup power supply is supplied to a second load; in response to a state value indicating a charging state of the backup power supply decreasing to a first threshold during the fail-safe control, execute an advance notice process for giving a user advance notice that a vehicle will be stopped; and in response to the state value decreasing to a second threshold which is smaller than the first threshold and which indicates a safety limit of the backup power supply, execute a power supply stop process for stopping supply of the electric power from the backup power supply.