Discharge time, h
OPERATION AND CONSTRUCTION
Lead-Acid Storage Batteries
Figure 9. Typical effects of discharge rate on battery capacity.
Generating Stations and Substations .
Effects of Discharge Rate and Temperature on Capacity and Life
The rate at which a battery is discharged and its operating temperature have a profound
effect on its capacity and life. An example of the effect of discharge rate on battery capacity
is shown in Figure 9 for traction batteries. This figure shows that batteries discharged at a
low rate will be able to deliver a higher capacity than those discharged at a high rate.
The depth of discharge also affects the life of a battery. As shown in Figure 10 for a typical
traction battery, discharges beyond about 80% of capacity can be expected to shorten battery
Colder operating temperatures will yield a little extra life, but also lower the capacity of lead-
acid cells. High temperatures yield higher capacity (see Figure 11) but have a detrimental
effect on life.