BATTERY PACK

A battery pack (1) includes: paired supporting members (35); a battery module (3, 5, 7) disposed between the supporting members (35); and a stack member (43) supporting the battery module (3, 5, 7) by linking the supporting members to each other. An extending portion (43a) protruding from the battery module (3, 5, 7) is formed by extending an end portion of the stack member (43). Accessories (12) are attached to a side surface on a side where the extending portion (43a) of the stack member (43) is disposed, the side surface being one of side surfaces of the battery pack which are provided with the paired supporting members (35).