You will be VERY happy with the Duralites, I know I am! Their service is second to none, I had a problem that was my fault, and they replaced the battery with a larger capicty redundant battery right there, no questions asked! The Duralites have the Cell Balancing and Safe Charge circuitry built in, which to my knowledge gives a balanced charge to each of the cells. In Duralites electric packs with the balancing, you can NOTICE the power as opposed to a normal pack. IMO they're better than any other pack out there, and you can't go wrong with their service either. Thanks Duralite!