Instructables

Home made electric wheelchair build any advice on motors batteries or anything appreciated?

Hi (newbie) Im thinking of building my own electric wheelchair and have a few questions.
When wiring multiple batteries to the motor controller, is it possible to (for example) if having 9 batteries, wire them in groups of three.
So have three sets of three. Three in parallel, wired to be three groups in series. Therefore i could use three switches to be able to turn off some of  the batteries. Reason for this is so that if going slowly i could have more control. 
Also i was thinking of differential steering with maybe two Etek motors, they would power the front wheels due to the torque (potential flipping). Any ideas how many batteries and the best type to use (extreme speed needed lol).
Other ideas of potential motors, any advice or knowledge greatly received



rickharris2 years ago
Commercial electric wheel chairs power the large main wheels through a geared motor.

They often have a small set of anti tip wheels at the back.

You WILL as Steve says need PWM control must I have seen use 2 batteries in series to give 24 volts.

Your going to be looking at 2 x 100 watt motors at least and perhaps 2 x 200 watts.
To give you enough torque.

Aim for a walking pace speed.
cameron11888 (author)  rickharris2 years ago
Yeh soz when i said motor control, i meant the PWM
i'm thinking of an english company called 4qd, they have alot of choice.
Any experience I was thinking of even more power and ii'll gear the motor to the wheels via a single crank!
The 4QD stuff IME isn't as flexible as the Dimension stuff.
Only drive 1 wheel - avoids the need for a differential and works fine for relatively flat ground.

I deduce your in the UK so why not keep any eye out for a second hand mobility scooter and modify that to your needs. Supermarkets are a good source I bought 2 this way both working and just in need of a little TLC.
cameron11888 (author)  rickharris2 years ago
I'm afraid i need a joystick control, thats why i think the diff steering is best (really easy aswell)
DON'T just switch the motors straight to the batteries - they'll break your neck with the jerk, or at least give you whiplash.

You really MUST use some acceleration control, and PWM to control the speed.

I heartily recommend Dimension Engineering's motor drivers.

Steve