Jon - you don't mention if it dies at full stick, and you take the stick back down, then it comes back, or if it comes on keeping the stick at full all the time.

Most BEC (battery elimination circuits) are set so that you DO have time to fly home, just without much motor. MOST of them reset, when you take throttle all the way off, then bring it back up. It's designed that way, so you have full servos the whole way down, you land dead stick, but you can have very short little burst's of power, to help make it back to the field. If when it dies, and you leave the stick up, see if it takes off running again, without having to reset with zero throttle. Now, be CAREFUL when you do this test - if it comes back on, it will be coming back at full throttle. And if it does, it's trying to tell you that it is drawing too much current, overloading the controller, and shutting itself down.

However, if it dies, and won't start up until you take the throttle all the way down, and back up, it's probably your batteries. But even then, if you are at full throttle, you should notice a decline in RPM quite a bit before it dies, as the battery voltage drops.

Also, when it dies, see if you still have servo's. I think if it's overloaded, the servos will stop, or be erratic, when the motor dies, and if the battery is low, just the motor will stop. Never tried it, but it's a thought. Perhaps tomorrow I'l brave the cold, and check it out....

Hope this helps...

R