Power wheelchair batteries are considered to be the most important part of the wheelchair as it is the source of power that allows the chair to move; therefore, selecting the correct battery is an important decision. Manufacturers design batteries using lead acid because they are available, inexpensive, rechargeable and available in different size for different wheelchairs. The batteries are grouped together based on their size and are assigned a standard number that is used when describing the battery. Typically a power wheelchair that is running on 10 amperes can last for 3 to 10 hours of continuous use.

Like automobiles batteries which use lead-acid batteries, they are the same size of power wheelchair batteries but they should never be used on a wheelchair. The reasoning behind this is that automobile batteries are used to start the car and are designed to provide a short but large burst of energy. Because of this the battery is never fully discharged at full capacity.

There are two types of lead-acid batteries: wet-cell batteries and gel-cell batteries. Most of the wheelchairs in the market can use both of the battery but manufacturer generally use gel-cell batteries because of environmental and maintenance factor that involve the wet-cell battery. When comparing the two types of batteries the wet-cell tends to provide more power and has a larger capacity. Studies have showed that the wet-cell battery travels 1.25 times faster then the gel-cell battery when using the same power wheelchair. There are two types of wet-cell batteries: the vented and the sealed (maintenance free). The vented wet-cell battery maintenance is required as water is needed to be added to the battery as it evaporates. Also when adding water to the battery, the user is exposed to acidic material, which can cause burns to the skin and eventually corrode the wheelchair. Chemical spill can occur when the battery is overfilled. This happens during incorrect charging of the battery. The sealed wet-gel battery is a closed system therefore water is not needed to be added but chemical spill may occur due to boiling or damaged case.

Sealed lead-acid batteries are an example of batteries that can be used in wheelchairs which are sealed and maintenance free. The way it is designed is that it's spill proof and safe to operate in any position is it placed. Due to its leak proof design there is no need special handling method. . They are also designed in high impact resistant battery cases that are made from non-conductive ABS plastic or styrene. All of there material in which the case is made from have great resistance to shock, vibration, chemical and heat.

The sealed lead-acid battery can provide dependable service that last up to four to five years or 200 and 1000 charges and discharges depending on the average depth of discharge. Because of the vast designs of battery operated wheelchairs, these batteries can be operated in over 40 models. Since there is low internal resistance this allows for discharge currents of up to ten time the battery capacity.

In storage a fully charged battery is able to last up to a year at room temperatures discharging at 2-3% per month before charging is required compared to other types of batteries which self-discharge at a rate of 20-30% per month. When the storage temperature is lower the battery shelf life tends to be greater.

When being operated it can be operate at temperatures of -20 degrees Celsius to 60 degrees Celsius and charging temperatures of -20 degrees to 50 degrees Celsius. When the batteries have experienced deep discharge, special separators, advanced plate composition, and a carefully balanced electrolyte system will help improve the battery recover it power.

Since each battery has their own pros and cons users may want to consider purchasing both a wet-cell battery for daily usage or range and power and a gel-cell for traveling or everyday use. When comparing the two types of batteries, the wet-cell is less expensive, greater capacity and more powerful. The gel-cell is approved for use on airlines, has a low potential for chemical spills, and low maintenance.

When charging the battery there are two type of charging methods: manual or automatic. The manual charging method is requires constant supervision and if overcharged it may damage the battery. Therefore the automatic charger is the most effective method. As it shuts off when it is done charging but it should be unplugged from the charger after it is done or it may damage the battery. Only recently manufacturers have been producing an integrated charger which is an advantage.