Capacity-Rating of a Lead Acid Accumulator

Capacity-Rating of a Lead Acid Accumulator Points : Capacity-Rating of a Lead Acid Accumulator The capacity of a battery can be expressed in ampere hours (Ah) or watt hours (Wh). The former is however, the more commonly used expression. e.g. A battery capable of 80 ampere hours. If the average voltage per element in the given case is 1.95 volts, the watt hour capacity of the given battery is product of the average voltage and the ampere-hour capacity, i.e., 80 x 1.95 of 156 watt hours per element. The capacity of the same cell will decrease if the discharge time is decreased or discharge current is increased. The other important factor is the final voltage per element. The complete specification for expressing battery capacity will be denoted as 80 AhJ2O hr/i .8 volts per cell 150 C. Which means the battery will discharge to 1.8 volts/cell in 20 hours at operating temperature of 150 C at a current of 4 amperes. If the final voltage/cell is allowed to, go down to say 1.75 volts, the capacity will improve to say 90 Amp-hours. If on the other hand the discharge rate is increased say within 10 hours the capacity may be reduced to 70 amp-hours.