The disclosure provides a rechargeable battery module. In the rechargeable battery module including a plurality of unit batteries, the unit batteries include: an electrode assembly including a first electrode, a second electrode, and a separator between the first and second electrodes; a case having a polygonal column shape for accommodating the electrode assembly; and first and second plates respectively sealing openings formed at opposite sides of the case, wherein a surface of the case of a unit battery of the unit batteries contacts a neighboring unit battery of the unit batteries.