During the monthly or quarterly maintenance checks, measure and record the battery’s voltage and each cell’s specific gravity. A SG difference of 0.025 or higher between cells indicates an equalization charge is needed. To perform an equalization charge on an FLA battery:
Not all users will want or be able to check the electrolyte’s SG on a monthly or quarterly basis. A more general method is to set a predetermined routine equalization maintenance on a monthly, quarterly, or biannual basis without checking either voltage or SG. To keep it simple once the equalization process has started, charge time can be set depending on the battery bank and charger’s size, and how often the batteries are charged to 100%. The amount of time typically will range from two to five hours.
If it’s your first time dealing with a battery-inverter system, it will take some time to understand the ebbs and flows of the system’s readings in a “normal” day of charging and discharging, and recognize if something is wrong. Checking the battery’s voltage and state of charge every day can provide a valuable orientation to the system—you’ll begin to understand what is (and isn’t) normal.
Using a monthly battery-inverter maintenance checklist can help you stay organized and help you pinpoint recurring issues with your battery system.