you should NEVER run the batteries down as this will destroy them for surely. 80% is THE max you should run these lipo's down to. I suggest you get a few more batteries, I got 6 2200-25C batteries for $20USD delivered to my door. More batteries means you don't have to run your batteries down so far or work them as hard. Equal longer lasting batteries. When your electronics have a hard time holding ur heli it means ur battery is needing a charge... something to thing about

happy fly'n