POWER SUPPLY DEVICE

A power supply device includes a driving control device and an auxiliary control device, the vehicle including a main power source, an auxiliary power source, and a supply path, the supply path being a path configured to be opened and closed according to a state of a start switch of the vehicle. The driving control device is a device that controls a state of equipment installed in the vehicle and the auxiliary control device is a device that controls a state of the auxiliary power source. The driving control device is configured to execute a storage process, a permission signal transmission process, and an initial value process, and the auxiliary control device is configured to execute a permission signal reception process and a stop process.