when I connect batteries to my hexrotor, the esc started beeping again. After connecting and disconnecting battery multiple times, the beeping stops, but the QgroundControl shows that accelerometer and gyrometer need caliberation and also the pixhawk lED turns red and keeps blinking. I could not figure it out, why this is happening. Also it even flew once perfectly after caliberating accelerometer and gyrometer but then after disconnecting and connecting battery again, the beeping of ESC came back. I am unable to figure out the problem and I would be grateful if you can give me some insights. Thanks again.