Battery pack

The battery pack has battery blocks 10 housed in a battery case 3, and each battery block 10 has a plurality of batteries 1, which can be charged, disposed in fixed positions in a battery holder 2. The battery pack has a plurality of battery blocks 10 disposed at given intervals in the battery case 3, and hollow partitions 32 enclosing hollow regions 33 open at the battery case 3 surfaces are provided between adjacent battery blocks 10. The battery blocks 10 are disposed in a manner thermally coupled with the hollow partitions 32.