It's surprising how little lead-acid industrial battery systems have changed over 150 years. Despite the invention of other power storage technologies such as lithium-ion, this inexpensive technology is still the common way to power devices from electric wheelchairs to heavy loading equipment. Although the cells are reliable, the Achilles' heel of this technology is sulfation.
What Is Sulfation?
First let's delve into a little bit of chemistry to explain why sulfation happens in industrial battery systems. Each cell in a battery contains two plates immersed in sulfuric acid. One plate is made of lead and one of lead dioxide. During operation the metal plates react with the sulfuric acid to produce a flow of electricity by transforming the lead compounds into lead sulfate. This is sulfation.
Charging a battery runs the reaction in reverse. Lead sulfate becomes lead or lead dioxide again and the battery is restored to its original condition--in theory at least. In real life, the process has a small amount of inefficiency that prevents all the sulfates from breaking down so each time you cycle a battery it loses a small amount of its ability to hold a charge.
Soft And Hard Sulfation
The leading reason industrial battery systems build up sulfation is inadequate recharge. When batteries are not given their full 14-16 hour recharge, they can't break down all the sulfates and can't return to their previous state. However even this soft sulfation can be reversed by occasionally overcharging the batteries to break up any residual sulfates.
Unfortunately, soft sulfation isn't the only problem. If the sulfates are left on the plates long enough due to inadequate charging, then they eventually transform into hard sulfation. Hard sulfation is made up of larger and sturdier crystals and is effectively impossible to remove from the plates. Also called permanent sulfation, these crystals cause irreversible loss of charge capacity and accelerate the eventual death of the battery.
Stop Sulfation Before It Starts
A proper charging schedule is the best way to minimize sulfation in industrial battery systems. Batteries get most of their charge in the first few hours of charging, prompting fleet managers to reduce charging times to save money by stocking fewer batteries. This is a false economy because these undercharged batteries will need more frequent replacement.
Short charge times are commonly the result of charging power cells without removing them from forklifts. The truck is completely out of service and managers want to get vehicles back out on the floor quickly. Instead of driving the forklift into the recharge area, replace the battery with a fully-charged cell and take the drained unit to be recharged. This keeps the trucks in service without jeopardizing the life of the battery.
The best way to reduce fleet expenses is to give your equipment proper maintenance. A few dollars spent today keeping your industrial battery systems going will pay off in the months and years to come.