VRLA Type Batteries

Has anyone come across a VRLA battery bank that was installed and the shipping vent caps were never removed. The battery bank has been in service for 3 years. It’s obvious that gassing has occurred. The fluid levels were low. Some of the jars were bulging. The flame arrestors were found in a box on the floor never installed. We were able to remove the shipping caps and fill the batteries with distilled water. We installed all of the flame arrestors when we were done filling the batteries. The contractor wanted us to test the batteries. We advised that the batteries needed to equalize charge and we should wait a few months before we test. The owner insisted we test the batteries. All the specific gravity results came out low and the owner wanted us to add sulfuric acid to the batteries.

I pushed back pretty hard on the situation and informed them that all of the water had evaporated, leaving a much higher specific gravity. We added water and there wasn’t enough time for the water to mix with the sulfuric acid, which lead to the lower specific gravity readings. We returned a month later to retest and the specific gravity of almost all batteries are back in the required range. But the cell voltages still appear high.

Does anyone know what effect “gassing” has on individual cell voltage? Literature on this matter is very hard to come by.

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