How much does the specific gravity of a lead acid battery electrolyte change with temperature?

The specific gravity of a lead acid battery electrolyte indeed changes with temperature, specifically decreasing as temperature increases. The correct value of 0.004 for every 10 degrees Celsius reflects the established correlation between temperature and the specific gravity of the electrolyte. As the temperature rises, the density of the electrolyte decreases, causing the specific gravity reading to drop.

This understanding is critical for battery maintenance and management, as accurate monitoring of specific gravity is essential for assessing the state of charge of the battery. Failure to account for temperature variations can lead to misleading readings, affecting battery performance and reliability.

In practice, mechanics and technicians must adjust their measurements according to temperature to ensure they accurately interpret the battery's state. Thus, the answer emphasizing a change of 0.004 for every 10 degrees presents the most accurate representation of this phenomenon in lead acid batteries.