Specific gravity is affected by which of the following combinations?

Specific gravity is affected by which of the following combinations?

• A. State of charge
• B. Temperature
• C. Both state of charge and temperature
• D. Electrolyte color

Answer: (C)

Specific gravity of a lead-acid battery electrolyte depends on both how charged the battery is and the temperature of the electrolyte. When the battery is more charged, more sulfuric acid is present in solution, increasing density and raising the SG. As the battery discharges, water content increases and acid concentration drops, lowering the SG. Temperature also changes density: warmer electrolyte is less dense and gives a lower SG reading, while cooler electrolyte is denser and yields a higher SG reading. Because of this, SG measurements are often temperature‑compensated to a standard reference. Electrolyte color does not determine SG. So the combination that affects SG is both state of charge and temperature.

Specific gravity of a lead-acid battery electrolyte depends on both how charged the battery is and the temperature of the electrolyte. When the battery is more charged, more sulfuric acid is present in solution, increasing density and raising the SG. As the battery discharges, water content increases and acid concentration drops, lowering the SG. Temperature also changes density: warmer electrolyte is less dense and gives a lower SG reading, while cooler electrolyte is denser and yields a higher SG reading. Because of this, SG measurements are often temperature‑compensated to a standard reference. Electrolyte color does not determine SG. So the combination that affects SG is both state of charge and temperature.