Flying over a lake this morning with my son. Calibration went fine. auto take off. Hover was rock Solid. we flew around for a bout 5 minutes. Nothing out of the ordinary. Then my screen starts blinking a red message saying "Critical Battery Error".....I was seeing visions of my p3p at the bottom of the lake. I immediately flew the p3 towards shore and had my son catch it. You will never guess why I was getting this message.....My son turned off the battery and said to me "Maybe you should have pushed the battery in firmer until it clicked and locked into place. Apparently, Dad, who is usually the over cautious one, inserted the battery, but did not click it in place. There was a good millimeter gap between the battery and the p3p. I know we are quick to find faults with our p3's, but I am amazed with this technology and the fact that it warned me of this battery error. I also feel like there was an Angel watching out for me and not letting the battery fall out and my p3p crashing into the lake. The lesson to be learned" MAKE SURE THE BATTERY IS CLICKED INTO PLACE" I will never do that again.