Switchblade - I always charge at 4 amps running mod. Do you have some way to check the amp draw of your motors? You can tune your motors for less amp draw, lighter motor springs, receiver pack mild profile on the speed control.
Jag - the pack wasn't in the correct. I had one heat like that once. You want the pack on the far right, with positive connection on the bottom right hand side (where you solder the positive lead on) across the top be nothing but battery bars connecting cells (or the wire on split packs).
take care
john