Patent ID: 8148938

Claim:
A lead storage battery, comprising: a positive electrode plate which holds a positive electrode active material; and a negative electrode plate which holds a negative electrode active material, wherein the content rate of lead sulfate relative to the positive electrode active material is set in the range of from 3% by mass to 11% by mass, and the content rate of lead sulfate relative to the negative electrode active material is set in the range of from 2% by mass to 6% by mass, the positive electrode plate and the negative electrode plate extend along a vertical direction, an upper end of each of the positive electrode plate and the negative electrode plate is formed into a collecting portion, each of the positive electrode plate and the negative electrode plate is equally divided into three portions in a vertical direction, the three portions being an upper portion, a middle portion, and a lower portion in this order from an upper side, the content rate of lead sulfate relative to a positive electrode active material to be held on the lower portion of the positive electrode plate is three times or less of the content rate of lead sulfate relative to a positive electrode active material to be held on the upper portion of the positive electrode plate, and the content rate of lead sulfate relative to a negative electrode active material to be held on the lower portion of the negative electrode plate is nine times or less of the content rate of lead sulfate relative to a negative electrode active material to be held on the upper portion of the negative electrode plate.