I just installed the Viper Copperhead VX4.39 in the Rustler. We'll I go to try it out and it'll barely run 2mph, I call Viper to see if they can help me out. I start explaining what it's doing then go on to tell him that I'm using the stock 7cell, 3000mah, 8.4v Nihm battery till I can get a Lipo. He says that my battery is the whole problem, that the 4 pole motor and the ESC need more draw than the Nimh battery could ever give. So I get off the phone with him and order a 2 cell, 5000mah, 40c lipo from SPC. My question is did I get the right battery and is this true that my Nimh battery the problem? Advice would be great.