I just saw someone riding a Brompton with home-made conversion kit. He was so fast I could barely follow him on my hybrid :-)
At the red light, he just told me he built it himself, that it took a bit of electronics, and off he was.
The black battery, which looked like my scooter's lead battery, was sitting in the front where the Brompton bag goes, and it looks like the electric motor was in the front wheel.
Google tells me that commercial conversion kits cost several hundred $/€'s, so I wanted to ask geeks here:
1. How much would the parts cost to build a home-made solution?
2. What technical skills do you need to do this yourself?