Sealed Lead-Acid Battery Information
99% of all Mobility Scooters and Power Wheelchairs use Two, 12 Volt, Deep Cycle, Sealed Lead Acid Batteries. The two batteries are mainly wired in "series" to produce 24 Volts.
Amp Hours is the second major factor when looking at batteries. Basically an Amp Hour (Ah) is the amount of energy a battery holds. The more Amp Hours in a battery the further the mobility vehicle will go.
Charging
First, plug the battery charger’s plug into a power socket. Then connect the charger to the battery pack. Remove the charger upon turning green.
Do not overcharge the battery overnight.
Storage
Store the battery after fully charging it
Store it at room temperature or lower
Remove the battery from the equipment
Charge it every 6 months, or as recommended by the manual
Avoid deep discharge
Choose proper float voltages to avoid sulfation and corrosion
What affects the range?
According to the ISO 7176-4 standard, the range is the distance that an electric wheelchair can cover on even ground under constant travel conditions and with a fully charged battery at around 20 °C. Normally, these ideal conditions do not apply to everyday life. Uneven roads, unfavourable wind conditions, hilly terrain etc. cause the wheelchair to consume more power, which consequently reduces its range. The stated range may also be affected by frequent acceleration, braking, steering corrections, the actual topography and other factors.
Roll Resistance
Roll resistance is a very important factor. For example, if the roll resistance is 6 % instead of 3 %, the range is reduced by half.
The roll resistance can be optimised by the correct tyre pressure. Tip: To maximise the range, use the maximum permissible tyre pressure.
Slopes
The range is also reduced by half if the wheelchair is climbing a 3 % slope instead of travelling on even terrain. On a 12 % slope, the range is only 1⁄5 of the range which is possible on level terrain. In reality, of course, a journey will always include a combination of upward slopes, downward slopes and level stretches. When going downhill, only some of the generated energy can be fed back to the battery. The maximum possible range can only be achieved with full batteries and full capacity. As a user, you can also increase the range by adapting your driving style.
Weight
The range is affected by the total weight of the wheelchair, baggage and user. Excess weight on the wheelchair, such as backpacks, should be avoided as much as possible.
Wheelchair geometry and dimensions
The l camber incline, wheelbase, diameter of the front castor wheels, front/rear load distribution and left/right wheel alignment also have a significant effect on a wheelchair’s roll resistance.
Ideal conditions:
0° wheel camber incline
Front/rear load distribution of 20:80
Symmetrical wheel alignment Long wheelbase
Front wheels as large as possible with solid rubber tyre
Temperature
The battery performance decreases as the temperature falls because the electrical resistance is increased. Therefore in winter, the usual range is likely to be reduced..
Starting and Braking
As with a car, frequent start and stop, steering and braking are less economical than continually driving at the same speed.