Patent ID: 7732090

Claim:
A sealed rectangular battery, comprising: a rectangular shaped battery case whose cross-section is oblong, said battery case comprising a rectangular shaped case body with a bottom and a lid closing an opened upper surface of the case body in a sealing manner; and an explosion-proof valve arranged near one of two opposing short sides of a main surface wall of the lid; wherein the explosion-proof valve consists of a V-cut groove concavely formed in a V-shape or U-shape in which a central bent part is positioned at a central location in the main surface wall of the lid, and a thin wall formed by the V-cut groove, and wherein cut grooves connecting each of two ends of the V-cut groove and each of two long sides of the main surface wall of the lid which are parallel to each other, respectively, are cut and formed in an inner side of the main surface wall of the lid.