Probably what you'd call an "ideal conditions" test. An indoor hover was all I did (maybe a couple of 360º spins in there.) After 15 minutes I had one green led left on the battery and steady flashing red LEDs on the P2. I flew for maybe two minutes with the red LEDs. I didn't bother to push it any farther because when I'm outside and I see flashing red, I head back anyway. Now at least I know about how long that is.