Patent ID: 7514179

Claim:
A valve-regulated lead-acid battery comprising: an electrode plate group; and an electrolyte impregnated into and retained by said electrode plate group, said electrode plate group comprising: positive electrode plates that each include a positive electrode current collector comprising a Sn-containing lead alloy, and a positive electrode active material retained by said positive electrode current collector; negative electrode plates that each include a negative electrode current collector comprising a lead alloy, and a negative electrode active material retained by said negative electrode current collector; and separators, wherein Sn content in said positive electrode current collector is 1.6 to 2.5% by mass, and pore volume per unit mass of said negative electrode active material is 0.115 to 0.150 cm 3 /g, and part of said electrolyte is a free electrolyte that is free from said electrode plate group, and said free electrolyte is in contact with said separators.