A battery pack includes a plurality of secondary batteries, each including a first electrode terminal and a second electrode terminal protruding from a cap plate, and a plurality of busbars, each electrically coupling first electrode terminal of one of the secondary batteries and the second electrode terminal of an adjacent one of the secondary batteries, wherein the busbars and the second electrode terminals are forcibly deformed to be coupled to each other, and wherein the busbars are welded to the first electrode terminals.