Electrolyte Density Check

The specific gravity of the battery electrolyte changes with temperature. An increase in the temperature of the electrolyte leads to a decrease in its density, and vice versa, a decrease in temperature leads to an increase in its density.

The specific gravity value of a fully charged battery should be between 1.260 and 1.280 g/cm³ at an electrolyte temperature of 26.7°C. The measured value of specific gravity should be corrected by adding 4 points (0,004) for every 5.56°C if the temperature is above 26.7°C, or subtract 4 points for every 5.56°C if the temperature is below 26.7°C.

Density should never be measured immediately after adding water. Water and electrolyte must be mixed either by charging for several minutes at a low charging current, or by holding the battery for 1 hour.

Attention! Density difference of 50 points (0,050) or more between one or more battery cells indicates that the battery is defective and needs to be replaced.