I went to record DDBB last night, got the opener, but about 80 minutes into the Dirty Dozen, I look over and notice that the phantom and headphone monitor is off. I try turning them on, but no luck. I power off, unplug the battery, reconnect, power on and then turn on phantom power. About 30 seconds later it goes back off. By this time, my wife and friends have already left and the only reason I'm sitting there is to get a complete recording, so I leave as well. I've never had this problem before - does it sound like the battery started dying? I fully charged it beforehand. It's a 3Ah RC style battery, so I should have had about 6hrs and only used maybe 3. I drained the battery and recharged it and it appears fine, but I'd like to avoid this again.