Recently this IPhone 4s, running on IOS 9.3.5, is shedding Battery power rapidly ( full charge lasts four hours maximum). Is there anything in Settings which might tell me why? Is it the hardware or the software?
I inserted a new battery about two months ago (before this problem arose) and it worked properly. However it is an old phone and the cover screws are missing. Recently the phone lost all power and went dead. I reset the Battery connections, and it worked, but the drain on battery power recurred. I then got a new battery and inserted it. However this made no difference to the problem.
I have checked various instructions for preserving battery life and followed them, but it makes no real difference. Wondering what might be the cause?