Heavy Duty Battery Charger For Forklift

While there are many battery chemistries today, and new types becoming commercially viable over time, we deal with the lead acid types, flooded, AGM, and true Gel, as they are widely used in the applications we specialize in. A typical lead acid battery cell has two plate types, one of lead and one of lead dioxide, both in contact with the sulfuric acid electrolyte as either a liquid, absorbed in a mat (AGM), or a gel. The lead dioxide (PbO₂) plate reacts with the sulfuric acid (H₂SO₄) electrolyte resulting in hydrogen ions and oxygen ions (which make water) and lead sulfate (PbSO₄) on the plate. The lead plate reacts with the electrolyte (sulfuric acid) and leaves lead sulfate (PbSO₄), and a free electron. Discharge of the battery (allowing electrons to leave the battery) results in the build up of lead sulfate on the plates and water dilution of the acid. The specific gravity of the electrolyte as measured with a hydrometer in flooded batteries, indicates its relative charge (strength), or level of dilution (discharge). The reversibility of this reaction gives us the usefulness of a lead acid battery.

Charging the battery is reversing the process above, and involves subjecting the battery to voltages higher than its existing voltage. The higher the voltage, the faster the charge rate, subject to some limitations. There is a gassing point to consider, and true gel batteries have a lower peak charge voltage, because bubbles can occur in the gel which don't dissipate, and result in battery damage. The lead sulfate crystals are broken down (more or less successfully) in the charge cycle. Sometimes some crystals remain, or sometimes a battery is left partially discharged where the crystals of lead sulfate harden, and reduce the capacity of the battery to be charged. This is what desulfation (desulphation)is about.