Patent attributes
A power supply device for a vehicle that is chargeable from an external power supply provided external to the vehicle, including a main battery and a battery pack that is attachable to and detachable from the vehicle. The battery pack includes a sub battery for driving electric loads common to the main battery and the sub battery, and a connector provided with a first storage unit storing information related to the sub battery. The power supply device for the vehicle further includes a control device performing control related to the main battery, and reading the information from the first storage unit and performing control related to the sub battery.