Thought I'd share my battery story here real quick.
I thought the lights were acting funny the night before, so yesterday morning I wanted to hover my P2V and watch the lights. No big deal. Just hover for a couple mins. So I grabbed what appeared to be my most charged battery which had 2 solid green lights on it and went outside (this battery hadn't been used in several months and was in storage charge, but did have two solid green lights).
Since I was just hovering I didn't use an app or the mobile device.
Turned it on and the lights were fine. Watched the satellites go 4, 5, 6, 7.... watched the compass direction lock, home point lock. Everything seems fine. Started the motors. And as it's sitting there on the ground with the props just starting to spin in idle, the lights all go out. All of them. No lights. Is that right? I'm not even sure. Is it possible I've never noticed this? I use Naza M. Sticks are centered. Both S switches are up. Props idling. No lights.
Hmm. So I launch to see what happens. The lights go on and everything seems fine. It hovers perfectly although it does tend to rise a fall a bit but it's kinda windy out.
I'm watching it as it hovers in front of me and I can see the battery now has the 1st light solid and the 2nd light blinking. Okay. Less than 50%. No biggy. I watch it some more while it deals with the wind.
And within about 30 secs, the taillights are flashing RED. What?
I look again at the battery while it's hovering in front of me. Now it's only got ONE green light and it's blinking! Less than 12%! Already? In less than a minute? How can this be?
Well I better land it. As I begin to land it, it starts going UP. No no no. I plunged the left stick DOWN and thankfully it did come down to a few inches from the ground and then in a bit of a panic I CSC'd so it wouldn't go up again and the craft dropped a couple inches and tipped and the motors stopped. No damage.
Went inside and checked the battery. It was at 11%. The cells were all BALANCED (which I think is pretty good for a battery at 11%). Lifetime percentage is 93%,
Moral of the story: ALWAYS ALWAYS ALWAYS BEGIN FLIGHT WITH A FULLY CHARGED BATTERY.