Electrolyte Specific Gravity Check
PROCEDURE

1. Battery electrolyte specific gravity changes with temperature. An increase in temperature decreases specific gravity, and vice versa.

2. The specific gravity of electrolyte in a fully charged battery should be between 1.260 and 1.280 at 27 °C. Correct the specific gravity by adding 0.04 points for every 5.6 °C above 27 °C, or by subtracting 0.04 points for every 5.6 °C below 27 °C.

For example:
Hydrometer reading – 1.280 at 5.6 °C.
Correct the specific gravity by 0.028 points according to the temperature difference. The true specific gravity is 1.252.
1.280–0.028=1.252
A difference of 50 points or more in electrolyte specific gravity between battery cells indicates that the battery is faulty and must be replaced.
Test yourself
A quick Hyundai Accent quiz: every answer comes with an explanation and a link to the manual page.