US Patent 7252903 Battery pack

The battery 2 of the battery pack is temporarily held in a mold 30 to form a molded resin region 1, synthetic resin injected into the mold cavity 31 to form the molded resin region 1 attaches to the battery 2, and the molded resin region 1 attaches to a safety valve opening surface 20 established at the battery safety valve opening region 9. Further, insulating material 15 is attached at the interface between the battery safety valve opening surface 20 and the molded resin region 1 in a position which closes off the safety valve opening region 9.