Poor battery life on iPad air with M2 - I found the issue

About one year ago, I purchased the iPad air with M2 (13 inches). Battery life was very poor under 5 hours. Even discharging overnight. Went 3-4 times to the Apple store to have it fixed or replaced, but they’ve always refused to change my product, saying nothing was wrong with it. Last week, accidentally, I found the problem. I was using the Apple Pencil Pro. Misplaced it, borrowed a friend’s regular Apple pencil usb-c. Boom! Problem solved! Found my Apple pencil pro and restarted using it: bang! Problem came back.

This is not a scientific research, but people with similar issues might want to check that out.