Abstract: A pressure relief valve, according to the invention, is mounted on a vent orifice providing a gas passageway from an interior plenum of a battery or a cell thereof to the ambient atmosphere. The valve fits on the vent orifice and opens to release gas at a high threshold battery gas pressure and reseals the vent orifice when the internal pressure of the battery drops to a low threshold.

Abstract: A grid structure for the positive electrode of a lead-acid battery cell is composed of several substructures (modules), typically having mutually identical geometric designs. Each of the substructures includes a plurality of metallic members having closed geometric shapes, each contained within another, which satisfy a specific growth ratio relationship, namely, that the ratio of the surface area to cross-section area of any member is no greater than such ratio for a member contained within it. In a preferred embodiment, each such substructure is composed of a plurality of concentric rectangles, each (except the outermost) contained within another. Each rectangle is formed by four lead (or lead alloy) rod-like strips.

Abstract: Many post seals for lead-acid batteries make use of compression seals. These seals, when used on the positive post, are often subject to abnormal anodic corrosion. The invention is a lead-acid battery in which the positive post is made of a tin-lead alloy (generally from 0.1 to 1.2 weight percent tin). The use of such an alloy at the positive post greatly reduces the rate of anodic corrosion.