A rechargeable battery includes an electrode assembly; a case accommodating the electrode assembly therein; a cap plate configured to close and seal an opening of the case; first and second electrode terminals extending through the cap plate and electrically coupled to the electrode assembly; and an external short-circuiter configured to electrically isolate or short-circuit the cap plate and the first terminal from or to each other, the cap plate being electrically coupled to the second electrode terminal. The external short-circuiter includes a membrane configured to close and seal a short-circuit opening in the cap plate, a short-circuit tab electrically coupled to the first electrode terminal and located at a side of the membrane, and the short-circuit tab includes a short-circuit protrusion, the short-circuit protrusion being configured to be separated from or short-circuited to the membrane. The membrane and the short-circuit protrusion have substantially the same resistivity.