A rechargeable battery includes: an electrode assembly including a first electrode, a second electrode, a separator between the first and second electrodes, and first and second electrode tabs respectively coupled to the first and second electrodes; a case accommodating the electrode assembly and coupled to the first electrode tab; and a cap assembly sealing an opening in the case. The cap assembly includes: a cap plate covering the opening in the case; and a terminal plate coupled to the cap plate. The terminal plate includes: a flange portion coupled to and electrically insulated from the cap plate; and a tab connecting portion protruding from the flange portion toward the electrode assembly and extending through a terminal opening in the cap plate to be coupled to the second electrode tab. The terminal plate has a flat outer surface, and the tab connecting portion has a flat inner surface.