Equalization (EQ) charges are an important step in maintaining flooded solar battery systems. Equalizing your solar battery bank prevents sulfation and acid stratification.
What is an Equalization Charge in Solar Battery Systems?
An EQ charge is basically an overcharge of the battery bank. You can set the equalization voltage and time in the charge controller. See chart for voltage settings:
| Voltage Setting | Volts/Cell (VPC) | 12 Volts | 24 Volts | 48 Volts |
| Daily Charge (Absorption) | 2.42 | 14.5 | 29.0 | 58.1 |
| Equalize | 2.58 | 15.5 | 31.0 | 61.9 |
| Float | 2.25 | 13.5 | 27.0 | 54.0 |
The EQ charge equalizes the specific gravity in all cells and fully charges the battery bank, in most cases.
Battery Sulfation in Solar Battery Systems
Battery sulfation occurs when your battery bank doesn’t reach a full charge on a daily basis. During the discharge phase, the sulfuric acid is absorbed into the positive plate. During the charge phase, the acid is purged from the plate. If all of the acid is not purged, your battery is not fully charged. The longer the acid stays in the plate, the harder it will be to remove. An EQ charge will purge the remaining acid from the positive plates. If the acid remains on the plates, it will crystallize, or become sulfated. Once this happens, the plate will begin to corrode. Because of the corrosion, you will lose the ability to use that portion of the plate, therefore losing capacity.
Acid Stratification in Solar Battery Systems
Acid stratification is the “separation” of the sulfuric acid. Since acid is denser than water, you will have a heavier concentration on the bottom and lighter on the top. The effect of stratification has a negative impact on battery life. Because there is a heavier concentration at the bottom, the lower portion of the plate will corrode faster than normal.
How Does an Equalization Charge Fix Sulfation and Stratification?
Since an EQ charge is an overcharge, above the gassing point, the bubbles stir up the acid. The activity eliminates stratification since it won’t give the acid a chance to separate. The overcharge also purges the remaining acid from the positive plate.
As always, American Battery Corporation is here to answer your questions and concerns. Give us a call or stop by – we love to solve problems. Remember, “We Sell Batteries – Knowledge and Service Are Fee”.