I always liked mini bikes and go karts. I got my first Briggs and Stratton 3hp minibike when I was 6. by the time I was 8 i had shaved the head to make more power. I decided to make an electric powered one. That way there is less noise and more fun. I thought maybe the lack of engine noise would detract from it but it made it better. I was able to sneak up on my wife one night as she came home from work. She never heard it coming....
Step 1: Picking a Motor
I thought about using a number of different motors but I had this GE 36V motor that had a base mount very similar to the mounting pattern of the gas engine so it made life easy.
Step 2: Picking Batteries
I really the baby Hawkers or the Cyclon for their low internal resistance but I ended up going with large gel cells for range. turns out they are pretty good on power too. plus with only 3 batteries in a nice rectangle configuration I was able to make a frame from old bed frame angle iron and used a single ratcheting strap to secure them
Step 3: Picking a Controller
I wanted good control so I used a Curtis controller from a forklift. I mounted it to an old car amplifier shell as a heat sink.
Step 4: How to Back Up
At some point you will need to back up. I pulled the reversing contactors out of another golf cart and used some copper battery straps and copper tubing to mate them together in a nice neat small package. too bad the wires are so big...
Step 5: Wires and connections
Luckily I had plenty of scrap #2 wire from an old UPS. I use the hammer style crimper tools to attach the lugs. I like to wrap the finished crimp with tape. It doesn't matter what color tape since I then cover that with heat shrink tubing. It makes the ends look really neat. Even better than the "Professionally" made battery cables I looked at. I used good quality battery disconnects to minimize losses in the high current wires.