Typically, heavy-duty wheelchairs require extra design to provide reinforced stability. Basically, the frame, axle, suspension, wheels, engine and battery all need extra strength. However, with heavy-duty wheelchairs the most common problem is the motor, which if not properly designed will fail under the increased weight.
The batteries in power wheelchairs are sealed lead acid batteries (SLA). The batteries are either wet or dry cell batteries and provide four to five amps of power. These batteries are usually charged by using a standard electrical outlet when the chair is not in use.
Power wheelchairs can be purchased in front-wheel, rear-wheel, center-wheel of four-wheel drive. For flat terrains, rear-wheel and center-wheel drive is most effective. electric wheel chair