Burning up my ESC always happened to me when I have been wrenching on my RC between races and all of the sudden I'm up for racing and I rush to plug in my battery without paying attention to inboard plug polarity.
This can happen very easily because different manufactures have the polarities on different sides as you can see below. Venom and SMC are opposite so if you use both batteries it is easy to make the mistake.
So Here is the Solution !!!! Polarity Stickers !!!
Hope this tip helps you!!!!