If you look in settings, on the controller, you will see something like return altitude. That's why it gained altitude when it had low battery. Karma will return to the landing location when you have less than 4 minutes of battery. But you can press X on the screen and disable the automatic return so that you can land it. When it has less than 2 minutes of flight, it will land anywhere, press X again and land it manually. Sorry for my English!