This past weekend I was testing a new bait dropper with my P4. Everything was going fine until I got a low battery warning. I landed the drone and switched it off. Removed the battery and replaced it with a charged one. I restarted the drone, and it took a while to connect with the console and Ipad. I think I saw something about no GPS signal or something on the screen. Nonetheless it started up, but did not hover at the usual 1.2m.Instead it accelerated upwards and flew away from me. It was not responding to my commands via the joystick at all. In no time it was about 150m away in the distance at around 25m in height. I also noticed low battery alarm. All along I was trying to regain flight control. Suddenly I managed to get control back and the drone returned to where I landed it. At this stage the battery had only 1 led flashing. It was a nerve wrecking experience!!! So I still have no idea what really happened. Anyone have some advice for me please?