Mobility Info - UK
Powered Wheelchairs
Power chairs or electric wheelchairs run on one or two 12 volt rechargeable batteries, each weighing about 10kg. Usually operated by a joystick, power chairs offer speed and comfort. This type of chair is useful for people whose level of disability means they do not have the strength or coordination to operate a self-propelled wheelchair, as well as for people who cannot rely on a helper to push them all the time in an attendant-propelled chair.
Electric wheelchairs for indoor use tend to have small wheels, which helps manoeuvrability. Outdoor chairs are bigger, with larger tyres, giving them a wide turning circle. Most people will find a model that is a compromise between the two will be most practical, depending on where and when they are most likely to use it.
While the advice in this guide pertains specifically to electrically powered chairs, much of the information in the companion piece “Buying Guide For Wheelchairs” (q.v.) is also of relevance.
Considerations Before Purchase
Because their frames have to support batteries, motors and gears, powered wheelchairs are bulkier and heavier than self- or attendant-propelled chairs. For this reason, make sure that there is enough space at home to manoeuvre the chair and to pass through doorways. Many homes will also need to have ramps installed to allow access indoors. A secure, waterproof place with an easily accessible power point is essential for recharging the chair’s batteries.
The wheelchair user should have good eyesight and the necessary faculties to operate the equipment. Anyone with visual, perceptual or intellectual impairment should seek a medical assessment before opting for a power chair.
The joystick control on a power chair is normally gripped between the thumb and forefinger. Some people can take a while to adjust to the sensitivity of the controls, although some chairs feature controls that can be programmed to react to varying degrees of hand skill.
Powered chairs are only movable manually when the motor is disengaged, so it is vital that the user can get close enough to transfer. Whereas a standard wheelchair can be brought to the user, with a power chair it is more convenient if the user can approach the chair. Moreover, most power chairs are not easy to transport due to their weight and the fact that they are less likely to be foldable. Even when they have some detachable parts, these can still be quite heavy. For transportation, help will be needed to lift, carry or disassemble the chair, although ramps and hoists can assist with loading into a vehicle.
Many chairs have a good battery range of up to 25 miles per charge, but, with a maximum speed on the pavement of 4mph, they are not a replacement for a car. In any case, the batteries’ range is affected by their condition, the occupant’s weight, the terrain (hills and uneven ground will sap power), any accessories used (such as lights) and weather conditions (batteries are less efficient in cold weather).
Power Chair Features And Controls
Chairs with a rigid frame are stronger but can be more difficult to transport. For those chairs that do fold, the batteries typically have to be removed first. Some chairs have similar sized wheels at the front and rear, while others have larger drive wheels at the front or back. The chair’s motor directs power to the drive wheels; those situated at the front offer manoeuvrability whereas rear drive wheels provide better grip and power on uneven ground. Increasingly, some power chairs have six wheels with the drive wheels located centrally. This arrangement gives a tight turning circle.
A freewheel facility allows the motor to be disengaged and the chair to be pushed manually, such as when it is being loaded onto a vehicle. In normal use, the wheelchair’s brakes function automatically when the accelerator control or joystick is released; additionally, some chairs have a manual handbrake for extra security. The seats on power chairs tend to be more substantial and comfortable than those on standard wheelchairs, in keeping with their more substantial size and specifications.
A power chair’s control console is normally situated on the left or right armrest, to suit the user. Typically, the console accommodates the on/off switch, the joystick to drive and steer, a dial or switch to limit speed if necessary, a battery power indicator and controls for lights and a horn, if used. The latter are more common on chairs specifically designed for outdoor use.
The on/off key can be removed when the chair is left unattended. Turning is controlled by moving the joystick to the left or the right, or backwards to reverse. A light touch on the joystick advances the chair slowly; firmer pressure increases the speed. Some chairs have the option of dual control. In such cases, a second control console is situated on one of the pushing handles so that a helper can drive instead. A simple switch determines which console is being used to operate the chair.
For people who are unable to operate a joystick, there are other solutions for controlling the chair, such as chin or foot-operated controls, suck/blow switches worked by the mouth, and voice activated controls.
Kerb climbers are useful accessories that can be fitted to power chairs, although some already have them as an integral feature. These are arc or wheel shaped devices that help lift the front wheels onto the kerb. Without them, it is very difficult to climb a kerb that is higher than a few centimetres, but kerbs up to 13cm high can usually be negotiated once they have been fitted. The kerb climbers are either mounted beside the front wheels or fixed centrally. The more powerful outdoor chairs with bigger tyres can often climb kerbs through power alone, but whatever the case, it is better to find a dropped kerb where possible. Certain chairs also incorporate anti-tip devices or stabilising wheels that offer improved stability when climbing kerbs.
A stair climbing facility is available on some of the more advanced power chairs. A more complex control console allows the chair and its wheels to transform into the configuration required to safely climb or descend stairs. For the wheelchair-using driver, there are special power chairs compatible with a car transfer system that raises the chair and its occupant into the space where the usual driver or passenger seat is located. In the Carony system, the power chair’s seat detaches from the wheels to be installed directly in the car, allowing the occupant to sit and drive from a more ideal position.
Batteries
Electric wheelchairs are powered by one or two 12 volt rechargeable batteries. Larger, heavier batteries give a longer range. There are two main types of batteries used: lead acid/wet batteries and gel batteries. The former need to be topped up regularly with distilled water but, because of the extra maintenance involved, they are becoming less common. They need to be charged in a well-ventilated area because they are liable to give off fumes (not poisonous) when doing so. Gel batteries have the advantage of being maintenance free. However, they tend to be more expensive to replace and do not last as long.
Batteries can be recharged overnight. As they are usually charged in situ, it is essential that there is an accessible mains electricity socket where the wheelchair is stored. Most chargers have a cut-out mechanism to prevent overcharging and an indicator light to tell you when charging has finished. Overcharging reduces the life of the batteries.
The batteries of chairs that are not in use for a while should still be charged occasionally to prevent them decaying. This is especially important if the power chair has not been used for more than a few days, because daily use of the equipment will increase the batteries’ lifespan. The correct charger supplied with the batteries should always be used to charge them.
