Cylindrical battery

A metallic casing for cylindrical batteries comprising said metallic casing and being used for the making of cylindrical batteries in which the outside diameter of the metallic casing of the finished battery is L2=A, and characterized by the external dimension of the metallic casing satisfying the relationship L2>A.gtoreq.L3, L2 being the outside diameter at the central part of the metallic casing, and L3 being the outside diameter of the casing bottom where, as shown in FIG. 1(a) in a cross-section of the cylindrical metallic casing, the outside diameter L3 measured at the points P.sub.1 and O.sub.1 where the extended line X-Y of the flat casing bottom inner surface and the casing wall external surface cross is defined as the outside diameter of the casing bottom.

A non-aqueous cylindrical battery comprising a battery element, which consists of a strip-shaped positive electrode and negative electrode, which have metallic foil of no more than 0.03 mm in thickness as a current collector, being separated by a separator and wound into a jelly roll and being housed and sealed in a cylindrical metallic casing;

• in which said non-aqueous cylindrical battery an end of an electrode or electrode current collector of either the positive electrode or negative electrode is positioned on the outermost periphery of the aforementioned battery element, and after the said battery element has been housed in the aforementioned metallic cylindrical casing the outside diameter of the said cylindrical casing is reduced to give the non-aqueous cylindrical battery with a characteristic of increased contact strength between said end of an electrode or electrode current collector which is positioned at the outermost periphery of the battery element and the inner wall of the aforementioned metallic casing, the contact strength being defined as the difference D-d between the maximum outside diameter value D, in terms of mm, of the battery element prior to insertion in the metallic casing and the maximum inside diameter value d, in terms of mm, of the metallic casing in the finished battery.