Posted on: 11 May 2017
If you own a powerchair or electric wheelchair, you probably already know the most important component is the battery. A battery that doesn't hold a charge, fails to recharge, or quits working unexpectedly can be a serious inconvenience, at best, or even pose a threat to the health and welfare of user, at worst.
Traditionally, wet cell batteries have been used to power electric wheelchairs, but the wet cell battery has been supplanted by a superior battery type, the absorbed glass mat battery. Below is more information about absorbed glass mat batteries, including what you should know about their maintenance.
What Is an Absorbed Glass Mat Battery?
An absorbed glass mat (AGM) battery consists of a plastic enclosure and a series of metallic plates separated by fiberglass pads. In some instances, polyester is used as a substitute for fiberglass, but the key principle remains the same.
The fiberglass or polyester pads are saturated with an electrolyte (battery acid), and the reaction between the metal plates and electrolyte is what generates electric current.
Why are Absorbed Glass Mat Batteries Superior Technology?
Absorbed glass mat batteries function similar to wet cell batteries, but the build technology of AGM batteries is superior to wet cell batteries, also known as flooded cell batteries. Below are several reasons why AGM batteries are preferred for use in powering electric wheelchairs and powerchairs.
No Liquid Electrolyte
One of the biggest advantages of AGM batteries is that they contain no liquid electrolyte. The presence of a liquid electrolyte in conventional wet cell batteries means spills are an ever-present possibility.
However, since AGM batteries contain saturated pads, there is no possibility of leakage. This eliminates the need to worry about possible spills in the event a powerchair or wheelchair tips over.
Less Hydrogen Gas Generation
Another advantage of AGM batteries is the reduction in explosion risk. Wet cell batteries produce potentially hazardous amounts of hydrogen gas, but AGM batteries generate safe amounts of hydrogen. That means powerchair and wheelchair users can rest easy if their chair is confined during charging, for example.
Longer Battery Lifespan
Yet another benefit of using AGM batteries is their increased lifespan relative to wet cell batteries. In fact, AGM batteries can be expected to last longer than wet cell batteries. Longer battery lifespan means lower maintenance costs for powerchair and wheelchair users.
A big reason for this increased lifespan is lower internal resistance. This simply means the battery will conduct more electricity and generate much less heat as it is charged and discharged. Heat is destructive to batteries, in general, and AGM batteries stay cooler for long periods of time.
How Are Absorbed Glass Mat Batteries Best Maintained?
Even though AGM batteries are advantageous to wet cell batteries in almost every way, AGM batteries still require some maintenance and care. Here are a few maintenance tips to keep in mind:
Fully charge AGM batteries on a nightly basis - As with wet cell batteries, AGM batteries benefit most when charged fully on a nightly basis.
Use an approved battery charger - Purchase and use the correct battery charger for your AGM batteries. Cheap chargers may not properly charge AGM batteries and may even cause internal damage to the battery.
Keep battery cables tightly connected - Loose battery cables can cause arcing and potentially harm the batteries, so be sure to tighten all connections between batteries and cables.
Know the difference between deep cycle and starter batteries - Only deep cycle batteries should be used for operating electric wheelchairs and powerchairs. "Starter" batteries are not designed for deep, long discharge and will fail quickly if misused.