The Idea
Pedal cars are fun, but electric motors are quieter, simpler, and way more interesting to wire up yourself. One June, I decided that I want to convert a boring pedal car, into a cool electric go-kart
This was one of the most ambitious hardware projects I've taken on. It involved real mechanical work, high-current electrical systems, and a lot of problem-solving on the fly.
Intro & Disassembly
The first step was tearing the kart down completely. I removed all the components from the pedal car. Stripping it down gave me a clear picture of the frame geometry and where components could be mounted.
Plans & Parts
Before ordering anything, I mapped out the full system:
- Motor — A 36V brushless DC motor
- Motor controller — This is the brain of the kart. It handles all the connections.
- Battery pack — 3 12V Lead-Acid batteries, combined provide 36V.
- Relay — Protects against overcharge, overdischarge, and short circuits
- Throttle — A foot pedal, sending signals to tell the controller how fast to go
Key design consideration: There was no way that I could get the batteries on the frame of the car, so my dad and I went to a welder.
Assembly Progress
With parts in hand, I started building. I first went to the welder, who welded battery trays onto the kart. He also welded foot pedals, so you could keep your feet on the car itself. Now was the time to start installing. I started with the motor, and the axel. I mounted the motor, and connected it to the axel. Then I connected and wired the throttle pedals, on-off switch, and the forward and reverse switch. I then connected the relay, a brake button, and wired everything to the speed controller. Now it was time for a test.
Cable management was important — loose wiring near a spinning chain or motor is a safety hazard. Everything was secured with zip ties, grommets through the frame, and heat-shrink on all connections.
Electricals & Testing
After making sure all the wires were secure, I went out on the road for a test ride.
Test Ride
The first real test ride was a success. The go-kart accelerates way faster then the pedal car, with instant torque. The best thing is, you don't have to excersise! I measured the top speed at about 17 mph, which is very fast.
The conversion worked first time. Electric go-karts are way more fun to drive then a pedal car — the instant torque makes it super cool.
What I Learned
This project taught me a lot about electronics — specifically how to safely handle high-current DC systems, how battery management systems work, and how to program a brushless motor controller.
It also taught me a lot about mechanical fabrication. Adapting parts that weren't designed to fit together requires creative problem-solving and sometimes building custom adapters from scratch.
Next Steps
Next summer (2025) I decided to add regenerative braking. There was one main problem. Our current speed controller didn't support regen braking. So I set out looking for another controller. I found one from Kelly, that supported regenerative braking. This controller also supported programming, with their app. The process was fairly simple, though with me, it took a long time. I started out by removing all the connections (just in case something goes wrong), and rewiring everything to fit the Kelly controller. We got a new relay (big mistake), and wired everything up. When we went outside to test, the relay never engaged. You had to kick the relay a little bit for the coils to engage. To solve this issue, I tried thicker wires connecting the batteries. Still no luck. The problem was very simple. I had gotten a 60V relay (the previous one was 36V). This coils (which connected the power) wouldn't engage because there wasn't enough power. This took me a long time to figure out, and I went back to the orginal relay after I figured out that it supports regen braking. Once I got everything working, it was really fun. I fine-tuned the regen amounts in their app, and then I was done.