I would double check a few things.
Make sure you have applications not refreshing in the background. To toggle these, go to Settings > General > Background App Refresh. I would toggle off any unnecessary ones.
I would also verify that your apps are closed by double clicking the home button and swiping up on any apps you are not using.
Lastly, to see what applications are using the most battery life, go to Settings > Battery. Allow the "Battery Percentage" to load and see what apps are using your battery.
If none of these resolve the issue, I would recommend getting a diagnostics test run on your iPhone by an Apple store or an AASP (Apple Authorized Service Provider).
Good luck!
CrashBurner
CrashBurner wrote:
I would also verify that your apps are closed by double clicking the home button and swiping up on any apps you are not using.
This is something of an urban myth. It doesn't save battery life. In fact, it can actually cause your phone to use slightly more battery life re-opening apps rather than unsuspending them.
iOS 11 was a bit unique in that the entire file system needed to be updated. It takes about 24 hours while all the background stuff finishes up. During that time, significantly decreased battery life is not uncommon. If you're seeing a problem after that, something else is going on. The suggestion to check exactly what is using your battery given above is where I would start.
Then it's time to do as suggested and arrange to have Apple evaluate your phone.
I have previously tried all the suggested. There is nothing clear and obvious I updated when it came out so have had it for weeks with terrible battery life.
ios 11 has killed battery life on iphone 6s, anything to do?
