Apple introduced a bunch of new features with iOS 10 when it released a couple of months ago, but more recent incremental updates have given iPhone users more than they bargained form. There are complaints that installing the iOS 10.1.1 update is somehow making batteries drain faster than they normally would, as well as giving inaccurate readings

Source: Hot Hardware – iPhone Users Complain That iOS 10.1.1 Is Quickly Draining Their Batteries