A rechargeable battery module includes a plurality of unit cells adjacent to each other in a first direction, each unit cell including an electrode assembly in a case, a cap plate sealing an opening of the case, and an electrode terminal electrically connected to the electrode assembly through the cap plate, a bus bar electrically connecting electrode terminals of unit cells adjacent in the first direction, a module frame accommodating the plurality of unit cells, the module frame including at least two sidewalls spaced apart from each other in the first direction to restrict opposite sides of the first direction, and a bottom supporting the at least two side walls, a restricting member fixed to a top of the module frame, the restricting member being spaced apart from the bottom of the module frame along a second direction perpendicular to the first direction to restrict the second direction.