Ping batteries are excellent. They do need to be "babied" - and by this I mean not put in a cooler bag, as the BMS will overheat. The BMS needs air circulation or at least some venting. Like a homemade wooden box with outlets for air. I like wire mesh steel office trays zip tied into to the rear rack, with the Ping in a waterproof Plano marine tackle box bungied into the tray "snapping in", with a waterproof pannier cover in black over the whole assembly, for stealth/security. The tackle box is predrilled to let air from the battery compartment into the upper lid compartment of the tackle box without letting water in. I also "unplasticated" the BMS from the way it is sold, and treated it with conformal spray, as well as putting padding inside the box to shield the battery from impact, but not cover the BMS. I've got 4000 miles on the bike since I got the Pings and they are working great. I also keep the depth of discharge below 70 percent, just to be nice to them. The more battery you have watt-hour-wise, the more cycles you will get out them as you will have some overkill which enables a more conservative usage pattern. I like the LEDs which come on. They are comforting.