^^^good advice there. I have been flying primarily electrics for several years now, and have used several brands of lithium cells. As noted, there is not always a direct correlation between price and quality. What you DO want to keep in mind is the vendor. Reputable vendors tend to shy away from the brands that have a lot of cell failures, and will try to help you out if there is a problem. I would avoid buying packs through ebay, but that's just my preference. Thunder Power, Tanic, Apogee, Polyquest, and Etec cells have been my favorites so far. Commonsense RC has a variety of "budget" packs which may be a good alternative to ebay for cheap stuff, too. Good luck deciding!