BATTERY

PROBLEM TO BE SOLVED: To provide high-reliability heat welding by considering how to form an inclination and how to provide a welding margin when a surface to be welded has a part having an inclination with respect to a reference surface of a heat plate in order to improve holding energy per volume of a battery. SOLUTION: This battery uses a battery can or a lid made of a synthetic resin where a surface to be thermally welded by a heat plate is located on a bent surface. The height in the direction vertical to the reference surface of the heat plate of the welding margin formed on at least one welding surface of the battery can or the lid is set larger than that in a part parallel to the reference surface in a part having an angle of inclination with respect to the reference surface. In addition, for a case of a steap inclined surface, a relationship among the height H of the inclined surface, the height A' of the welding margin, and the limit of the inclination angle θ is shown in the figure. COPYRIGHT: (C)2005,JPO&NCIPI