There is definitely something wrong with iOS11 on the 5S.
I gave it another try today - completely fresh DFU install, set up as new rather than restore, left on charge all night so nobody can pretend it needs more time to "index" (not that that's actually a thing...) - it's just losing % for no reason. Me and my wife used our phones roughly the same today as we were out shopping - about 2-3 hours of usage total each. Mine is 5%, her's is 60% - she has a 5S on 10.3.3 still.
Laughable battery life.
PS - it's actually real http://bgr.com/2017/09/22/ios-11-battery-drain-iphone-ipad-apple/
I gave it another try today - completely fresh DFU install, set up as new rather than restore, left on charge all night so nobody can pretend it needs more time to "index" (not that that's actually a thing...) - it's just losing % for no reason. Me and my wife used our phones roughly the same today as we were out shopping - about 2-3 hours of usage total each. Mine is 5%, her's is 60% - she has a 5S on 10.3.3 still.
Laughable battery life.
PS - it's actually real http://bgr.com/2017/09/22/ios-11-battery-drain-iphone-ipad-apple/