US Patent 7879490 Lead battery and lead battery storage method

This invention provides a lead battery that becomes usable by injecting an electrolyte thereinto. The battery includes: positive and negative electrode plates each having a grid comprising a Pb—Ca based alloy; separators that separate the positive electrode plates from the negative electrode plates; the electrolyte comprising sulfuric acid; and a battery container accommodating the positive and negative electrode plates, the separators, and the electrolyte. The battery container is sealed, and part of the positive and negative electrode plates is immersed in the electrolyte. The height Y0 of the positive and negative electrode plates and the distance Y1 from the bottom of the positive and negative electrode plates to the level of the electrolyte satisfy the relation:15≦Y1/Y0×100≦60.