[RC-Monster Mike]

If the controller let out smoke, there is something wrong with it for sure. I doubt it has anything to do with the cell count, either. I have run my warrior on up to 22.2 volts with a hotter motor using the controllers bec and haven't had any trouble. Something probably shorted (exposed wires perhaps) and caused the "smoke". I am surprised it works at all. If you have a camera, take a pictures if you can see anything obvious and I will see if anything sticks out at me.