Battery containing foam polyurethane resin and method of making

Abstract

A sealed lead acid battery including a container; a cover connected to the container; a plurality of plate groups disposed in the container, each of the plate groups comprising a plurality of pairs of positive plates and negative plates separated, each from the other, by separators; an upper space within the container extending from the plates to the cover; a pair of straps disposed in the upper space; each of the plates having an upstanding lug; each of the lugs extending from the negative plates being connected to one of the straps; each of the lugs extending from the positive plates being connected to the other of the straps; and foam polyurethane resin filling a sufficient amount of the upper space to control the possibility of an explosion occurring due to the collection of gases within the container, the foam polyurethane having an apparent specific gravity of from 2 g/l to 50 g/l and an open cell structure.

Dependencies are inferred from the claim text.