This week, as part of our Innovation series of KARMA blogs, we chat with Eric van Olst, Chief Innovations Officer at KARMA to discuss the considerations around batteries and the range of wheelchair – and what are the different things that can impact a decision on what batteries can be used.
You may think that you’d just put the biggest batteries with the longest range possible into a chair, but what other things do we have to think about? And how could this change in the future?
Eric van Olst, Chief Innovations Officer at KARMA
Why is battery range important?
Range gives an individual the freedom of movement during the day, which in turn means more kilometers to drive. And also the battery range takes care of the use of all other power functions on your wheelchair.
What do you have to weigh up when thinking about range? Cost/Weight?
There are two main components creating range: the batteries and the drive motors.
You can have large capacity batteries, but if the drive motors have a low efficiency, your drive range can still be small. High efficiency motors in combination with high capacity batteries create the largest drive range.
When it comes to weight: weight is not always something negative. Large batteries may be heavy, but they also create a lower centre of gravity for the wheelchair, and this improves stability. As an example, if you need a wheelchair with standing function or wheelchair with seat lift, if the chassis is heavier this will give you more stability.
What are they made of?
Traditional batteries are made out of lead or acid constructions, newer technologies mean that batteries can be made out of several different Lithium Ion or polymer combinations.
How have batteries changed over time?
Battery technology had been standing still for a long time…. then the new technology batteries were used on smartphones and the development of new battery technology sped up.
From smartphones, the batteries became larger and were used on power tools. Then it was the e-bike and lately, the car industry embraced electric cars and batteries. Since that moment the industry started to develop the technology rapidly. The wheelchair industry worldwide has always been a small industry compared to the car industry, so we weren’t capable of speeding up technology. Ever since the car industry has embraced the electric vehicle, the wheelchair industry can start to benefit as well from these new developments. Hopefully, in time, the new battery technology will become more affordable too.
What other considerations do you need to have when it comes to batteries?
It is all down to what an individual’s needs from their own wheelchair. Do they need to drive long distances each day? Do they use it only indoors? Do they want to take the wheelchair in a car? All aspects of your daily use of the wheelchair can have an influence on the type or model of powered wheelchair that will fit your needs.
Where do you think battery technology will change in the future?
Batteries will become more and more efficient. So more energy per cubic volume. What to do with that efficiency? It depends, how the other components on a wheelchair develop. If the drive motors will also become more efficient, by definition you need less energy per mile driven. Therefore the batteries could become smaller, or the same size but with a much bigger driving range… It all depends on the demands of the user.
You can check out the full range of KARMA wheelchairs and find out more about our unique power functions on the KARMA website.