Hi guys. This is my first post on this forum after being read-only for a few years...
I just got one of these bikes last weekend. The seller suggested it had a dead battery, and a dead controller (He tried it with a working battery, and it did nothing.). I got it for 175 Euros.
It literally took less than 2 hours to get this thing going again, most of that time was spent massaging the battery which was sitting at 0 Volts. The supplied charger stopped after 5 minutes, so I charged it with a bench supply for ~2 hours at 5A, it was still stone cold. The controller was indeed bad, I'm not even going to bother looking at it any more.
I'm hooked, these things are amazing! I have a home built controller strapped to the side, which is slightly overpowered. (60V/100A). At the moment, it just uses a thumb throttle and regulates current to a maximum of 30A. I love the sound it makes when you change gears, it's like I'm driving a tiny muffled motor cycle.
The battery and motor both seem quite happy with 30 Amps, after riding around for about 20 minutes without any pedaling, the battery was flat. The motor was moderately warm (~40 C). It reaches 35 km/h in 6th gear, again.. no pedaling.
I want another one! Why are these so hard to find? They're brilliant. It' doesn't even have a Wiki... what's up with that?