PURPOSE: To prevent shortcircuit at the upper part of the group of electrodes as well as separation of active substance and thereby prolonging the cycle life by using as a retainer for said active substance a waved porous plate made of plastics such as polyorefin in addition to the grid made of lead alloy and by packaging said material with fine glass mat consisting mainly of unwoven cloth or glass fiber.

CONSTITUTION: A grid 2 with tab 1 made of lead alloy with 2.5wt% antimony in the size of 100×108mm divided into 16 sections each dimensioned as 25×23mm is pinched by nets 3 made of polypropylene with 1.5×1.5mm mesh, and they are pinched by polypropylene waved porous sheets 4, in the same mesh as the grid 2, of 1mm wide and 0.5mm thick and 0.8mm in the height of waving in such a way that their intersections are adjusted to the center of mesh of the grid 2, whereafter these porous sheets 4 are ultrasonically welded at their intersections. An unpacked pole plate not yet chemically formed is now obtained by pasting an active substance 5 to thus prepared composite base and subjecting to preliminary drying, and the surfaces of this pole plate are pinched by polyester unwoven cloth 6 of 0.5mm thick and their three open sides of periphery are sewed up with a thread 7 of polyester.