Sorry, I should have stated this more clearly. Yes, I was talking about an external BEC. The Castle Creations 10AMP Peak. I guess I just figured that if a RTF plane came with a receiver pack then the ESC probably did not have an internal BEC, why would a company spend the money to include something if they didn't have to.

Using a UBEC do you get any indication that you are about to run out of battery and if so what is it and how long do you have to get your plane down?