Rechargeable battery

The present invention refers to a secondary battery (100) including a case (26), an electrode assembly (10) being accommodated within the case (26), a cap plate (20) sealing an opening of the case (26) and a terminal portion (40) attached to the cap plate (20), wherein the terminal portion (40) comprises a terminal plate (42) being arranged on the cap plate (20) and electrically connected to the electrode assembly (10). The battery (100) is characterized in that the terminal portion further comprises an auxiliary plate (45, 46) electrically connecting the cap plate (20) to the terminal plate (42) and having a plurality of openings (451 b, 461).