Battery pack

A battery pack comprises a bare cell including a cap assembly having a terminal, a protection circuit module mounted to the bare cell, the protection circuit module comprising a protection circuit board and a protective device, the protection circuit board having a through hole arranged to permit welding of the protective device to the terminal through the through hole and a cover for covering the protection circuit module, the cover comprising a protrusion arranged to engage with the through hole to retain the cover to the protection circuit board.