A rechargeable battery includes an electrode assembly having a first electrode and a second electrode of different polarities, a case with an opening that houses the electrode assembly, the case having a pair of opposing first side walls, each first side wall of the pair of first side walls including at least one groove extending from the opening of the case to an opposite side of the case, a cap assembly coupled to the opening of the case to seal the case, a first current collecting member and a second current collecting member inside the case, the first and second current collecting members being connected to the first electrode and the second electrode, respectively, and a first terminal and a second terminal on the cap assembly, the first and second terminals being connected to the first current collecting member and the second current collecting member, respectively.