Are you hitting aux 5 for shut down? You need to make sure engine has gone down to idle speed/sound then hit aux 5 that puts into shut down sequence, and it should then shut down then turn power off to the track.
I personally never have installed a battery. I get the effect your suppose to by doing it the way I said, and no battery. The battery is suppose to just let the engine go into shut down once you turn power off.