I'm in new Zealand , i ve bought many batteries from a web site named BMS (don't know how to give a link) but they are by the time I get the cells & the right BMS it cost still a lot less than any other site --I am always looking for a cheaper source ,Ive learnt to make my own battery pack which is no cheaper than their cheap pack but realy good ballance for the bike ,i wish i could put picture of them. making sure the BMS is enough for bike motor is something one must be carefull of