What should the specific gravity of the electrolyte be in a fully charged lead-acid battery?

The specific gravity of the electrolyte in a fully charged lead-acid battery is typically between 1.275 and 1.300. This range is important because it indicates the concentration of sulfuric acid in the electrolyte solution. As a lead-acid battery charges, the electrolyte becomes denser due to the formation of lead sulfate and the conversion of water back into sulfuric acid.

Maintaining the specific gravity within this range ensures optimal performance of the battery and provides indicators about the state of charge. If the specific gravity is lower than this range, it may suggest that the battery is undercharged or has a low concentration of sulfuric acid, which can lead to reduced capacity and potentially irreversible damage. Conversely, if the specific gravity is higher than this range, it may indicate overcharging or the formation of excessive electrolyte evaporation, which can also harm the battery.

In summary, the correct answer reflects the typical range for a healthy, fully charged lead-acid battery, and this knowledge is essential for assessing battery health and maintenance practices.