I am using (2) 8000mah 7.4 Maxamp lipos in series, I havent had chance to run long enough to measure my times yet....also been wondering if the single 5000mah lipo will be enough run time for the e-revo would love a 8000mah 5s pack for it, but I bet that will be huge and very heavy...I like maxamps especialy the 3yr/300 warranty, what warranty do the flightpowers and NeuEnergy's have? I know maxamps is not the most powerful though... more middle of road performance vs Neu or flightpower batteries from what I have read