I have been reading on some recent cases of people's Phantoms dropping out of the sky after a sudden power loss,  took me a while to find this post I remembered from a month or so again.  http://forum.dji.com/forum.php?mod=viewthread&tid=32663  

I think this may pertain to the person who's Phantom went completely dark and crashed then the battery turned back on just lying there.   I just ran out time as far a searching for that post....   

Hi ,
This is really a rare incident . As it's winter in most countries now , I believe the low temperature is probably the most important factor we need to take care of . May be you can check this thread :http://forum.dji.com/thread-35249-1-1.html   

Does the battery scheme move from individual cell to individual cell (within the batteries), in order to keep pumping? Series or parallel? I've wondered if, when a crash happens, it's because the battery is switching from one cell (discharged) to another, and there's a failure there. Somehow. Just a thought.

there are too many Phantoms shutting down and falling from the air .. im on old FW and I have flew with half charged batteries with no problems but it seems to be newer FW that is responsible ... I know DJI says to fly with a fully charged battery but this seems to be a new problem and I feel sorry for the guys who have lost their birds because of something that should be addressed ....