LEAD-ACID BATTERY

PROBLEM TO BE SOLVED: To cast a grid body for a lead-acid battery with fewer pores by supplying molten metal from the lower side of a casting mold and directing a notch in a middle rib of the casting mold diagonally to the horizontal direction. SOLUTION: In a positive electrode grid body, middle ribs 4 in the height direction and in the width direction are positioned parallelly and orthogonally to a frame rib 5, and the middle ribs 4 are tilted at 45 deg. to the horizontal surface. Into this casting mold 1, molten metal 6 is supplied from the lower part of the casting mold 1 by means of a pump for forming a positive electrode grid body. As a result, the molten metal 6 flows toward the upper part of a grid body notch 2, while air 7 is discharged from the upper part of the casting mold 1. Then, an electrode plate, in which a paste type active material is applied to the positive electrode grid body, is aged, and a dried positive unformed plate and a conventional negative electrode unformed compound are alternately layered via a separator made of glass fiber unwoven fabric, and a sealed lead- acid battery with a cell unit of 200 Ah is assembled. Subsequently, dilute sulfuric acid aqueous solution is injected and battery cell formation is carried out for completing a battery.