My iPhone only works when plugged in.
My iPhone (iPhone 4s running iOS 9.3.5) suddenly turned off, I put it charging and 1 minute later it said that the battery was full. I took it off the charger and it immediately turned off and said the battery was at 0%. Now it only works when it is plugged in a wall. It isn't being recognized by my MacBook Air and it doesn't charge in it. Also, I bought a new charger at an Apple store and it is just 2 weeks old. It has never had any contact with water. Please help me by telling me if I can back up it to iTunes without a mac or pc and if there is any way I can get it working properly again.
Thank you.
iPhone 4S, iOS 9.3.5