US Patent 7927735 Secondary battery

A secondary battery having a porous filling member that occupies a portion of a molding space between a bare cell and a protective circuit board. The presence of the filling member makes it possible to uniformly apply a molding resin into the molding space and to reduce defects due to thickness irregularity of a mold or a surface defect thereof. The secondary battery includes a bare cell, a protective circuit module including a protective circuit arranged on a protective circuit board and a plurality of electrical connection members electrically connecting the protective circuit board to the bare cell, a filling member arranged between the bare cell and the protective circuit board and a mold covering the electrical connection members and the filling member.