Battery Cancer: How Sulfation Destroys Forklift Batteries And What You Can Do About It

Lead-acid industrial battery systems have been around for over 150 years and today’s batteries aren’t that different from the ones invented in 1859. Although these power cells are inexpensive and reliable, they eventually fall victim to a condition called sulfation.

How Lead-Acid Batteries Work

Lead-acid industrial battery systems are really pretty simple. Two plates are immersed in sulfuric acid: a negative plate of lead and a positive plate of lead dioxide. The cell provides power when the plates react with the sulfuric acid, producing deposits of lead sulfate on both terminals while generating a flow of electrons from the negative plate to the positive plate. The creation of lead sulfate is called sulfation.

When you recharge a power cell, you reverse this chemical reaction. The electrons flow in the other direction and the lead sulfate breaks down into sulfate ions and lead or lead dioxide. In the ideal world of a college physics class this process continues forever as the reaction is completely efficient. However in real life a small amount of sulfation remains after each recharge cycle, especially if not charged to full capacity, and the buildup eventually prevents the unit from holding a charge.

Reversible And Permanent Sulfation

Sulfation is not itself a bad thing. It is a normal part of the operation of industrial battery systems and the formation of these sulfur compounds is how the cell releases its stored power. Problems arise when a battery is not adequately recharged, preventing the sulfur compounds from breaking down completely. If the unit goes too long without a charge the small sulfate crystals, known as reversible or soft sulfation, evolve to larger and more stable sulfate crystals called hard sulfation.

Reversible sulfation is, as you might have guessed, reversible. If you overcharge a battery that has a reduced ability to hold a charge, you can break down the soft sulfation crystals and restore much of the cell’s function. However hard sulfation cannot be removed and will eventually require replacement of the power cell.

Preventing Sulfation

There is no way to make lead-acid industrial battery systems last forever, but you can prolong their lives by caring for them properly. The number one way to minimize sulfation deposits is to fully recharge batteries when they are drained. Power cells typically require a 16-hour recharge and yet many forklift fleets charge them only for 8 hours, or one shift, in order to keep more trucks in service.

A better option is to stock extra batteries and physically remove them for recharging rather than having the trucks sit idle during the recharge process. This allows you to keep your forklifts in operation 24/7 while giving the batteries the full 16+ hour charge and slowing down sulfation.

Take care of your industrial battery systems and they will take care of you. Practice proper maintenance and you will get more life from your power cells and save money on fleet expenses.