Patent ID: 7879490

Claim:
A lead battery that becomes usable by injecting an electrolyte thereinto, said lead battery comprising: positive electrode plates each including a positive electrode grid comprising a Pb—Ca based alloy, and a positive electrode active material retained by said positive electrode grid; negative electrode plates each including a negative electrode grid comprising a Pb—Ca based alloy, and a negative electrode active material retained by said negative electrode grid; separators that separate said positive electrode plates from said negative electrode plates; the electrolyte containing 7 to 27% by weight of sulfuric acid; and a battery container accommodating said positive and negative electrode plates, said separators, and said electrolyte, wherein said battery container is sealed, part of said positive and negative electrode plates is immersed in the electrolyte, and the height Y 0 of said positive and negative electrode plates and the distance Y 1 from the bottom of said positive and negative electrode plates to the level of said electrolyte satisfy the relation: 30≦ Y 1 /Y 0 ×100≦60, said lead battery is in a charged state without need for recharging.