Fechter's Vego Scooter
Fetcher does some amazing things with small scooters. He has to, he lives in San Francisco at the top of a steep hill and needs his scooters to have a lot of power to make it home.
Back in the day he got deep into Vego Hacking and developed 36 volt and 48 volt variants. The 36 volt variant can run on the stock controller and motor and I don't recall the 48 volt modifications required other than a forced air cooling system.