Need response from a Castle tech for MMM question

[BrianG]

Mine runs ok for the little I do. Since I'm still waiting to decide what lipos I'll be running in my MBX5/Corr truck, I haven't made a permanent batt tray, and so I just run on 4s a little here and there. So, not a whole lot of use.

What the tech said about using an external source doesn't sound right. If the on board BEC fails, it could be pulling down any external supply. Of course, it depends somewhat on what went wrong.