The thing that kills the life of batteries in the Warhead is the servo that controls forward/reverse. It's always active because it's putting pressure on the lever into the transmission. If you don't mind not having reverse, for a quick fix, I would disconnect that servo from the RX and cable tie the servo in place so that it is applying pressure to the lever towards the transmission. I did this until I ordered the forward-only shaft, and it worked great! =)