Thank you, Flecc, for your full report on Europe's different markets.
I would like just add that I think that in France, the best cycling forum website is Cyclurba, le vélo utile and e-bike market seems hardly going up with sales in Supermarket from 390E for a folding ebike!!
I know someone from Hambourg who bought last year the 905 SE Whisper by Internet, from "E-wheels.de"
I am not sure that 's still available but you can try EBIKESTORE Kleine Freiheit 48 22767 Hambourg
Good luck
No doubt about this Chinese product:
it is not a Li-ion battery but a Nickel (Cadmimum?) one, most of the other products are lead-acid batteries:
http://www.electraped.com/kingcharles.html
The best I have found is the MAGNUM UL1 , tested and approved by ART, with 16mm D and 107mmx260mm (so very heavy!) at a wonderful price of less
16 EUROS (with delivery in UK!) :
https://www.bike24.net/1.php?content=8;product=1974;pid=0;mid=0;ID=c819ac277f8f1981ea364f3cc8d03338