Playing around with different batteries in my cx2 I notice sometimes "bigger isn't always better" I have an Electrifly 720mah 2 cell 8c battery that weighs 36 grams (use it for my Helimax-Rotofly) and notice that the power outburst (although only 8c) is equivalent if not just a little more than the stock E-Flite 2 cell battery which is 9c and 800mah which weighs 43 grams. It's lighter with less power, but the heavier more power e-flite keeps the comparison almost equal..I shot a pic of it below next to the other batteries...7 gram difference...[sm=teeth_smile.gif]