Battery pack

A battery pack comprising:

• a plurality of battery cells;
• a housing accommodating the battery cells therein;
• a circulation path formed in the housing and through which a heat exchange fluid circulates so as to transfer the heat of the battery cells to the housing;
• and
• a blower for causing the fluid to flow through the circulation path, wherein:
• the circulation path comprises:
• a plurality of battery paths formed by gaps between adjacent battery cells,
• an inflow side space which is a space facing inlets of the battery paths, and
• an outflow side space which is a space facing outlets of the battery paths,
• a path along the housing which is a path that is different from the inflow side space and the outflow side space and extends along one or more inner surfaces of the housing,
• the circulation path is formed such that both of a flow velocity of the fluid in the inflow side space and a flow velocity of the fluid in the outflow side space are slower than a flow velocity of the fluid in the path along the housing,
• fins for exchanging heat with the fluid protruding into the path along the housing are provided on an inner surface of the housing,
• the path along the housing is divided into a fin region where the fins are arranged and a finless region communicating with the upstream side of the fin region and where the fins are not arranged, and
• an area of a fin inlet which is an inlet through which the fluid flows into the fin region is larger than an area of a finless inlet which is an inlet through which the fluid flows into the finless region.