Abstract: A sealed lead-acid battery formed by joining two halves of a battery container. Before joining, the separate halves have grids placed in adjacent recesses, separated by partition walls integral with the wall of the container half. Pairs of adjacent grids are electrically connected through the partition wall. The recesses are alternately filled with positive and negative active materials. Then the halves are joined with a porous separator in each cell of the combined halves separating positive and negative active materials.

Abstract: A specific gravity detecting apparatus for a lead-acid battery having two electrodes adapted to be immersed in an electrolyte to provide a potential difference therebetween which is indicative of the specific gravity of the electrolyte. One of the two electrodes is a lead electrode composed of a collector 6 made of lead and a lead alloy and a porous lead body 4 covered by an acid resistant porous sleeve 3; the other is a lead dioxide electrode composed of a collector 6' made of lead and a lead alloy and a porous lead dioxide body 5 covered by an acid- and oxidation-resistant porous sleeve 3'. The two electrodes are charged normally or as required while there is no necessity of obtaining specific gravity data, and later discharged with another lead electrode as an opposite electrode so that, in the open-circuit state, the potential difference between the lead electrode and the lead dioxide electrode is accurately determined.

Abstract: A pasted type lead-acid battery with greatly extended service life and capacity over the usable service life thereof has a glass mat, which may have a dual layer construction, disposed adjacent positive plates of assembled elements. Each plate is constructed as a grid having main and small members with the small members entirely embedded in an active material. Pressure is applied to the assembled element within disclosed ranges. The assembled elements may be pressurized by a binding band or pressure may be applied from outside the battery container. In the latter case, the side and bottom walls of the container are made pleat-shaped.

Abstract: A lead acid battery suitable for high power application, having elements comprising a plurality of positive and negative plates which are composed of grids formed with band-shaped portions at one end facing to the side wall of container, and layered one upon another with separators put therebetween in such a way that the respective band-shaped portions for the positive plates and negative plates respectively face to the opposing side walls of the container, the positive plates and the negative plates being respectively connected at least at a part of the length of said band-shaped portions to thereby form straps.