On my last flight the battery gauge stuck at 71%. I checked it a few times while the P2V was in the air as it seemed like I was getting an exceptionally long flight. Then realized it was not counting down. So I flew back home and just as I got it back close to me it went into self landing mode. I landed, turned the P2V off and left the app running. Turned the P2V on again, connected the network and got a battery reading of 28%. Haven't had a chance to fly since then to see if it will happen again. Anyone had a similar incident? Any thoughts on cause?