I just got 1,440wh's of 2170 cell batteries, 12ah and an 18ah @ 48v for $800 and also a 52v 870wh (15ah) 2170 cell one for $600 I've had for 8 months.....batteries obviously don't have to cost as much as the manufacturers are providing them for. They work on all three of my DIY/POS bikes so there is that.