Patent ID: 7712648

Claim:
A battery module manufacturing method for a battery module including: a gas duct member for covering safety valves of a cell group formed from a plurality of cells; and first and second side covers for covering the cell group and the gas duct member from one end to the other end in a direction where the cells are arranged, the cell group and the gas duct member being hermetically covered with a sealing member that is formed into a cylindrical shape and that is interposed between the first side cover member and the second side cover member, a first opening end section on one side of the sealing member enclosing the first side cover member and being thermally welded thereto, and a second opening end section on a remaining side of the sealing member enclosing the second side cover member and being thermally welded thereto, the method comprising the steps of: bringing a heater of a thermowelding apparatus into direct contact with an area to be thermally welded; and heating the heater, to thus perform thermowelding, wherein the heater is a strip-shaped heater having a main elongate surface and two terminal sections provided at opposite sides thereof, the main elongate surface extending substantially the length of the strip-shaped heater between the two terminal sections, the main elongate surface having two elongate side surfaces that extend the length of the main elongate surface between the two terminal sections and that are folded to respectively form an angle with the main elongate surface, and the main elongate surface being thermal-sprayed with polytetrafluoroethylene or fluoroplastics.