A Specific gravity level tester uses specific gravity and the number of floating discs to show state of charge. Accurate at all temperatures. Specific gravity levels are printed on the tough, see-through plastic body and feature a one-piece rubber bulb, neoprene tip.
If the specific gravity measures between 1.100 and 1.220, the battery must be recharged. If the specific gravity is below 1.225 or a variation of .20 or greater specific gravity between battery cells indicates a need for battery equalization charging or indicates a weak cell. If the specific gravity is between 1.225 and 1.265, the battery is ok to test. If the hydrometer has a temperature correction chart, be sure to adjust the reading for the battery’s temperature. Variance of specific gravity between cells is not significant on discharged batteries (batteries with specific gravities below 1.225). However, if there is a variance of 50 points (0.050) in a battery whose specific gravity is 1225 or more, that battery is defective.
