Equalization is required to mix the battery acid, and to bring every battery plate to an equal charge. Equalization should only be performed when required or once every six months. Over equalization or too often simply wastes the battery life. Equalization is required when the cell specific gravities vary from highest to lowest by +/- 0.015 (1.245 – 1.260 at full charge).

The exact equalization settings are dependent on the system voltage and battery type. However, equalization is to bring the batteries up to the specified equalization voltage and hold that charge for 1-2hours at a low current, without excessive heat. If the battery temperature rises to or exceeds 125ºF the battery should be immediately taken off of charge and allowed to cool before the equalization is continued.

There are two ways to determine that you have successfully achieved equalization, Remember the Equalize part of equalization is to get all the cells equal in voltage and Specific Gravity. You don’t need to do both, but you must do one right.

The first is by voltage readings of the individual cells, which is not possible with most 6 and 12 volt batteries. However you can get a close estimate of the overall bank by reading individual battery voltages, all must be within .05 volts of each other.

The second method, which will read all the individual cells, is when two consistent specific gravity readings are taken a half hour apart the battery is equalized. Obviously at this point all cells read equalSG and voltage.

Don’t fill the batteries first because you’re going to heat up the electrolyte and it will expand and make a mess. We recommend you add water to the battery cells half way through the equalization. This is to assure the water is completely mixed into the electrolyte.