ORIGINAL: ct420
It sounds like you have over-discharged the battery and ruined it. Lipo batteries are very sensitive to being overly discharged, and can go bad after just 1 time of this happening.
If you are flying until the heli can no longer hover out of ground effect, then you are almost certainly running the battery too low.
I ruined several batteries this same way when first starting out...
Thanks for confirming my suspicions. I guess tommorow I get to go buy a new battery and a voltmeter