TWI667836B

A lead-acid battery with enhanced initial capacity is provided without reducing the battery life. A lead-acid battery positive electrode is formed by filling a positive electrode active material paste into a grid substrate made of a lead alloy. The positive electrode active material paste is obtained by kneading a raw material including lead powder containing lead metal containing lead monoxide as a main component. The lead powder is adjusted such that it has a median size adjusted to 0.5 µm to 10 µm. The lead metal is adjusted such that it has an average value (average particle diameter T10 of the lead metal) of 10 µm to 35 µm for the particle diameters of top ten lead metal particles with the largest particle diameter as the lead metal is observed using a metallurgical microscope.