Patent ID: 7862931

Claim:
A lead-acid battery comprising: an electrolyte containing an aqueous solution of sulfuric acid; a positive electrode including a grid, an active material layer containing PbO powder and sulfuric acid, and a corrosion layer which suppresses permeation of the electrolyte into the grid and which is formed at the interface between the grid and the active material layer; and a negative electrode; wherein the grid is made of a lead-based alloy consisting of not less than 0.02% and not more than 0.045% by weight of calcium, not less than 0.4% and not more than 2.5% by weight of tin, not less than 0.005% and not more than 0.04% by weight of aluminum, not less than 0.002% and not more than 0.014% by weight of barium, and a balance of lead and unavoidable impurities.