A lot of people buy their 'mini PCC kit' then request one of the new single logo auto batterys with it, so for 36 bux with the 10% off SMILIN code you're getting a PCC (portable charger case), a box of 5 carts, and a nice battery, you can't beat that anywhere else. Plus if you want a usb or a wall charger they have them too for cheap.
They really do need to sort out the kits on their page though, it's confusing to know which batterys you're gonna get with each kit.