The kit now works well. I have two batteries that give me a 60-70 Km range (and I ordered a new one that should allow me to ride all day). Initially I experienced several problems due to a bad battery that I received (it lasted about 10-15 Km, i.e. less than half of the rated range) and due to customer support being slow in acknowledging that there was a problem. Eventually they sent me a replacement battery and everything was smooth. But it took over a month to resolve. And it should be easy to add a charge monitor to the controller, to check the health status of the battery and notify you when it no longer (or never, as in my case :-) ) holds the stated charge. So... technically great, logistically less great. But overall I am happy because the bike now works well and I enjoy riding it a lot!!