My emaxx will not go in reverse. It will only move forward. When I try to go in reverse, my emaxx just sits there & my battery packs
will get hot and smoke will come out of them. ???
The batteries get super hot after holding the throttle in reverse for about 5 seconds. Weird.

Do I have a defective speed control?

"Do I have a defective speed control?"

Yup. Pack it up with a $20 money order to Traxxas and they will replace it.