BATTERY ASSEMBLY

The problem addressed by the present invention is to provide a battery pack with improved assembly workability. The assembled battery pack (1) is provided with: a plurality of battery modules (2) stacked on each other, each provided with a case (27) accommodating a unit cell (21); and a through- bolt (4) that penetrates a through hole (28) formed in the cases (27) along the stacking direction of the battery modules (2) to connect the battery modules (2) each other. The battery modules (2) are further provided with an insertion auxiliary member (3) that is inserted into at least one opening (29) of the through hole (28), and the insertion auxiliary member (3) has a tapered portion (213) such that the inner diameter thereof gradually decreases towards the tip of the insertion auxiliary member (3).