I have a stock Slash with the Waterproof XL-5 ESC, when I connect my Lipo 2S 3200 20C Batt.....the wheels jump...meaning that it gets a split second of power to motor and makes the truck lurch forward. Is my cellshield bad? It is brand new, but could it be defective or I am doing something wrong...I did follow directions and it is hooked up properly..............???