- by Bryan Veldboom - updated on 1/26/2022
Electric wheelchairs provide mobility for millions of people who lack the ability to operate a manual wheelchair, while also making it much easier to access steep inclines and other challenging terrain. Electric wheelchairs accomplish all of this through the use of battery power. Today we'll be taking a closer look at wheelchair batteries. We'll outline the different types of batteries available to wheelchair users, break down a few of the pros and cons of each and share some valuable tips on how to charge and maintain them so you can get the best performance possible out of your electric wheelchair.
When discussing wheelchair batteries there are two important things to consider, voltage and chemistry. Let's start with voltage. All wheelchair batteries are 12 volt batteries, however most wheelchairs are powered by a 24 volt system. That means that you need two 12 volt batteries in order to run most electric wheelchairs.
When shopping for wheelchair batteries, it's important that both batteries have the same chemistry and battery capacity, which is measured in amp hours (Ah). Not sure what an amp hour is? No worries; an amp hour is just a fancy way of telling you how much amperage a battery can provide for exactly one hour. The more amp hours in a battery, the longer your wheelchair will be able to run.
Now let's talk chemistry. Electric wheelchairs can run on two different types of batteries: deep cycle AGM (short for Absorbed Glass Mat) batteries and gel batteries. Both are a type of Sealed Lead Acid (SLA) battery. SLA batteries produce electricity through a series of chemical reactions that take place between the plates packed inside them and a sulfuric acid solution called an electrolyte. The basic difference between AGM and gel batteries stems from differences in how the electrolyte is stored inside the battery.
In an AGM battery, the electrolyte is held in suspension by a series of fiberglass separators that hold the solution between the battery's plates. In a gel battery, the electrolyte contains a silica additive that turns the electrolyte into a gel-like mass. One other term that we should define here is deep cycle. Deep cycle batteries are engineered to provide small, sustained levels of power for long periods of time. This enhanced cycle life allows deep cycle batteries to be used for hours at a time, making them a great fit for use in wheelchairs.
Gel batteries have a number of advantages over AGM deep cycle options. For starters, gel batteries have longer overall lifespans. You can expect a gel battery to last roughly twice as long as an AGM option. Gel batteries also hold their charge for much longer than AGM batteries and have a better tolerance for extreme temperatures.
One disadvantage of gel batteries is that they will cost you more upfront, although this fact can be a bit misleading. Since gel batteries last much longer than AGMs, their longer lifespans can help even out this cost over the full life of the battery. Another disadvantage of gel batteries is that they don't recharge as quickly as AGM batteries. This is because gel batteries have very specific charging requirements and must be charged at a lower voltage in order to prevent them from overcharging.
A fully charged wheelchair battery is designed to provide around eight hours of use and last between one and two years. Your battery's actual lifespan, however, will depend on a number of factors, including how often you use your wheelchair, the amount of weight that you transport, the type of terrain you use it on and whether you are charging your wheelchair battery properly.
The most important rule to follow when charging a battery is to make sure that the charger you use is compatible with the chemistry and voltage of your battery. So, if you have two 12 volt gel sealed lead acid batteries in your wheelchair, the charger you use needs to be compatible with gel batteries and have an output of 24 volts. Many modern battery chargers like the Duracell Ultra Wheelchair Charger have different settings for different battery chemistries. When using a charger with multiple settings, always be sure it is set to the right chemistry before attempting to charge your battery.
Both under- and overcharging can be harmful to your battery. For that reason it's important to monitor the charging process to make sure that batteries are charging for the proper amount of time. Alternatively, you can pick up a smart or automatic charger. Automatic chargers monitor your battery to maintain the ideal charge. They will automatically switch themselves off to avoid overcharging your battery and begin charging again once your battery begins to discharge.
Here are a few additional steps to follow when charging your wheelchair battery.
If your battery is having a hard time holding a charge or isn't lasting as long as it used to, you should have the battery tested. Batteries Plus offers free battery testing. Just bring your wheelchair battery to the nearest Batteries Plus location and we'll let you know if it's still viable or needs to be replaced. If you do need a replacement, we have plenty of wheelchair batteries available, as well as a selection of wheelchair battery chargers.