POWER SUPPLY DEVICE AND VEHICLE PROVIDED WITH POWER SUPPLY DEVICE

A power supply device includes: a plurality of secondary battery cells; a pair of end plates disposed on end surfaces of a battery stack obtained by connecting the plurality of secondary battery cells to sandwich the battery stack; and a fastening member for fixing the end plates to each other. The end plate includes a first band body protruding from a main surface of the end plate on an upper end side of the end plate and second a band body protruding from the main surface of the end plate in a middle of the end plate. A space is formed in the second band body between the second band body and the main surface of the end plate.