A rechargeable battery pack includes a case with first and second openings, the first and second openings facing each other, a plurality of unit cells in the case, each unit cell including a rechargeable battery and having a longitudinal direction extending from the first opening of the case toward the second opening of the case, a first cover coupled to the first opening of the case, the first cover selectively connecting via elastic members terminals of the unit cells facing the first opening, and a second cover coupled to the second opening of the case, the second cover connecting via elastic members terminals of the unit cells facing the second opening in correspondence to terminals connected through the first cover.