Abstract: A battery pack includes a plurality of batteries, thermally conductive members which are in contact with the plurality of batteries, and a case which houses the plurality of batteries and the thermally conductive members. The case includes holding parts each of which is not in contact with an end surface of the thermally conductive member, regulates displacement of two surfaces of the thermally conductive member in a direction vertical to each of the two surfaces which are connected with the end surface and positioned on sides opposite to each other, is in contact with at least one of the two surfaces, and thereby holds an end part of the thermally conductive member.

Abstract: A partial structure of a battery pack includes: a battery group which is formed by stacking a plurality of layers, each of the layers being formed by arranging cylindrical batteries in parallel in a plane, the cylindrical batteries belonging to adjacent layers being arranged by shifting alignment pitches by a half pitch from each other between the adjacent layers; heat transfer plates, wherein each of the heat transfer plates is in contact with side surfaces of the cylindrical batteries arranged on both surfaces of each of the heat transfer plates, is formed by a heat transfer corrugated plate member, and extends through a gap between the cylindrical batteries along an alignment direction of the cylindrical batteries in the layers in the plane intersecting center axis lines of the cylindrical batteries, a first intersection direction intersecting the alignment direction or a second intersection direction intersecting the alignment direction and the first intersection direction; and a radiator which is arrange