2 Battery Drain
Initial reports seemed to have indicated that iOS 11.1 alleviated some of the battery drain issues present since the first version of iOS 11. It may have been too soon to call the issue fixed, however.
While some users are experiencing improved battery life, there are just as many who are reporting no noticeable change to their battery life. Worse still, a handful of reports seem to indicate that some users are experiencing worse battery drain. Not good. In the meantime, a portable battery pack or a battery case will help remedy the issue.