Explain the relationship between specific gravity and state of charge of a lead-acid battery.
The electrolyte in a lead-acid battery plays a direct role in the chemical reaction. The specific gravity decreases as the battery discharges and increases to its normal, original value as it is charged. The decrease in specific gravity on discharge is proportional to the ampere-hours discharged. However, while charging a lead-acid battery, the rise in specific gravity is not uniform, or proportional, to the amount of ampere-hours charged