The bikes i was watching in alibaba was a bit diferent and dificult to find in china, dont know why. They run double distance with one charge, normally are faster and better quality than the ones we usually see around. Anyway the extra battery added brought me some confort, so i will check the store Felix talked about. Check it out the bikes from alibaba:

http://www.alibaba.com/product-gs/23...un_F_6000.html

http://www.alibaba.com/product-gs/30..._G_6000Li.html this one is a dream...

http://www.alibaba.com/product-gs/44...C_SCOOTER.html

http://www.alibaba.com/product-gs/28...C_SCOOTER.html

http://www.alibaba.com/product-gs/37...n_D_4000W.html

This last exactly like my petrol one, but eletric:

http://www.alibaba.com/product-gs/28...C_SCOOTER.html

ps. if theres any informaton about where to buy one of this bikes around shanghai please let us know! tks