|Battery Application & Technology
In order to obtain maximum life from
lead-acid batteries, they should be disconnected from the
load once they have discharged their full capacity. The
cutoff voltage of a lead-acid cell is usually around 1.75 V.
However, the cutoff voltage is very sensitive to operating
temperature and discharge rate. Like batteries discharged at
a high rate will have a lower cutoff voltage than those
discharged at a low rate. Greater capacities are obtained at
higher temperatures and low discharge rates. The
manufacturer should specify cutoff voltages for various
operating temperatures and discharge rates.
Over discharge may cause difficulties in
recharging the cell by increasing the battery's internal
resistance. Also, over discharging may cause lead to be
precipitated in the separator and cause a short in the cell
or between cells.