Power wheelchairs from established brands cost $4,000 to $15,000 and are designed around a fully-integrated electronic stack — joystick, programmable controller, sealed brushless hub motors.
Power wheelchairs from established brands cost $4,000 to $15,000 and are designed around a fully-integrated electronic stack — joystick, programmable controller, sealed brushless hub motors. Insurance often won't cover them outside specific medical scenarios. A growing community of mobility hackers and occupational therapists has been building 'power-assist conversions' instead: keep your existing manual wheelchair, bolt on a known-good e-bike drivetrain, and end up with something that climbs hills and goes 25-30km on a charge for under $700 in parts.
The Bafang BBS02 mid-drive is the part most builds converge on.
The Bafang BBS02 mid-drive is the part most builds converge on. It's a 750W mid-drive motor designed for e-bike conversions; it's mass-produced, parts are a Google search away, the torque sensor variants give natural-feeling assist, and the form factor (a cylindrical block bolted under a frame) maps cleanly onto wheelchair geometry with a 3D-printed or laser-cut adapter plate. The motor drives the rear axle through a chain or belt; you keep the original wheels and brakes.
The non-obvious part is the control loop.
The non-obvious part is the control loop. You don't want a throttle-only setup because it's tiring (you have to constantly push) and unsafe (one wrong twitch sends you off a curb). The right setup uses a torque sensor on the pushrim — when you push the wheels, the motor adds proportional assist. When you stop pushing, it stops. A small thumb throttle stays as override for ramps and parking-lot situations. Regen on downhill is set conservatively so it feels like gentle braking, not a sudden grab.