Power Wheelchair Batteries: Understanding How Your Battery Works
If you or someone you know uses a power wheelchair, it is important to understand how the batteries work. Power wheelchair batteries need to be replaced every so often, so understanding the battery will help you to select the best battery for your chair. The wheelchair battery plays a large role in the way that your power wheelchair performs.
Usually, power wheelchair batteries are “deep cycle” lead-acid batteries, which means that they are designed to use most of the available capacity during each discharge cycle. The 3 main characteristics of deep-cycle lead-acid batteries are capacity, current rating, and cell type.
The capacity of the battery determines how long the battery can function and is expressed as ampere-hours (Ah). Most deep-cycle lead-acid batteries have a capacity ranging from 30-90 ampere-hours, or about 3-9 hours of continuous use for a wheelchair that runs on 10 amperes. Most people however, do not use their wheelchair continuously.
Battery current, or the rate of electron flow, is expressed in amperes (A). Basically, the larger the current rating, the greater the ease for the power wheelchair to travel over rough terrain and obstacles.
Cell type indicates whether the power wheelchair battery is wet-cell or gel-cell, the two main types of wheelchair batteries currently available. Both may be used in a power wheelchair, although manufacturers typically recommend gel-cell batteries due to maintenance and environmental concerns with the wet-cell type.
However, it should be noted that wet-cell batteries do have a larger capacity, and can therefore provide more power. They are usually less expensive than gel-cell type batteries, and so are often the first choice for many power wheelchair users. Wet-cell batteries come in vented and sealed versions:
* The vented type of wet-cell batteries must have water added periodically, due to water evaporation over time. Since the person doing the maintenance may be exposed to battery acid every time the battery case is opened to add water, this can be difficult and challenging. Chemical burns can occur very easily, and chemical spills can corrode the wheelchair.
* Sealed wet-cell batteries are a closed system, so one does not have to maintain the water level. Still, the potential exists for a chemical spill, due to boiling, or a damaged battery case. Because both of types of wet-cell batteries have chemicals, neither are allowed on aircraft.
Gel-cell lead-acid batteries are maintenance free, with no chance of chemical spills. Because of this, they are easily transported on aircraft. The major disadvantage of gel-cell batteries is that they typically have 10-20% less capacity than wet-cell batteries. They are also usually more expensive. But even so, unless the wheelchair user travels great distances on a daily basis, gel-cell batteries will probably be the best choice for most power wheelchair users.
One should also consider the battery charger when buying new power wheelchair batteries. It is important to make sure you have the correct charger for the type of battery you are using, since the wrong battery charger can cause permanent damage to the battery. As a deep-cycle battery, wheelchair batteries are meant to be almost completely drained before recharging. Most batteries can be recharged as much as 300 times before they must be replaced.
Understanding power wheelchair batteries can greatly help in deciding which is the best replacement battery to purchase, and will make certain that your wheelchair always operates at peak performance.