Abstract: A battery structure arranged to avoid the inefficiency problems which normally accompany container bulging in conventional absorbed electrolyte batteries such as sealed lead-acid batteries. The battery container is separated by partition walls into a plurality of working cells into which are closely fitted conventional stacks of plates and separators. The partition walls hold the plates and separators in intimate contact necessary for proper operation of the battery. Bulge compensating end cells are provided at either end of the battery between the working cells and the container end walls to accommodate pressure variations during battery operation. Compression means associated with the bulge compensating end cells maintains the plates and separators in intimate contact to maintain battery efficiency while permitting the container end walls to bulge.

Abstract: A method of casting metal straps on lugs of battery cell elements utilizes an electrically heatable mold having a strap cavity section and comprises introducing strap metal into the cavity section, conducting electrical current through the mold for heating the mold to a predetermined temperature in excess of the melting temperature of the strap metal, immersing the element lugs into the cavity, cooling the mold to a temperature below the solidification temperature of the strap metal and removing the element lugs from the cavity with straps cast thereon.

Abstract: An element stack and a method of making same is provided in which assembling a relatively large number of relatively small electrode plates into an element stack is facilitated by positioning a first set of electrode plates onto a strip of separator material in pre-selected locations and then affixing such plates to the strip. The resulting product may then be readily processed into the element stack by insertion of a second set of electrode plates of opposite polarity to the first set and then folding the separator in accordion fashion. The assembly method is amenable to automation and the resulting cell element stack may be handled as a unit thereby facilitating battery assembly.