The present invention refers to a rechargable battery including a case, an electrode assembly being accommodated within the case, a cap plate sealing an opening of the case and a terminal portion attached to the cap plate, wherein the terminal portion comprises a terminal plate being arranged on the cap plate and electrically connected to the electrode assembly. The battery is characterized in that the terminal portion further comprises an auxiliary plate electrically connecting the cap plate to the terminal plate and having a plurality of openings.