Chosen Solution
iPhone 6s v10.2.1 won’t charge in airplane mode. The charging symbol shows but the percentage doesn’t increase. I don’t think it’s just failing to update the percentage because once I turned off airplane mode, the percentage started at the point it was at and started increasing at the usual rate I expect. I restarted the phone a couple of times which had no impact. Not a huge issue but I now have to remember to fully charge before getting on the plane
Currently it is worth a shot of replacing the battery. you can get a great deal for 27 dollars at apple. that way, a) keep whatever warranty you have b) you get to keep the water seal c) If apple breaks it, they have to pay for it. https://www.apple.com/iphone-battery-and…