Battery Pack

A battery pack comprising:

• a first battery group and a second battery group in each of which a plurality of storage batteries are laminated, with each storage battery formed in a cuboid composed of a pair of wide surfaces and narrow surfaces other than the pair of wide surfaces, so that the wide surfaces are placed to face each other;
• and
• a heat transfer member,
• wherein the narrow surfaces other than the pair of wide surfaces include:
• a first narrow surface with an external terminal;
• a second narrow surface opposite the first narrow surface;
• and
• a third narrow surface as a side face other than the first narrow surface and the second narrow surface;
• wherein the first battery group and the second battery group are disposed in a case housing such that the third narrow surface of the first battery group and the third narrow surface of the second battery group face each other via the heat transfer member;
• and
• wherein the storage batteries of the battery pack include a terminal for connecting the battery groups to equipment outside the batteries.