I just contacted Apple support via chat to report 11.0.2 battery life issues, and I would encourage everyone to do the same. Apparently they are aware of the issues and working on it. Here is what they said (I only included the important parts): Oliver I really appreciate you chatting in to let me know that you’ve been having battery drainage issues since updating to 11.0.2. This is an issue that I do know the engineers are aware of and working on currently but every additional case and additional notes are great! Oliver I think the best thing to alleviate the issue for now is to turn off your background app refresh so that your apps aren’t using up battery as much even when the device isn’t in use. Mark Is it the same issue that I am describing? Oliver Some devices are appearing to experience faster than usual battery drain after updating to iOS 11—though I’m not sure of details further than that. I’m afraid. Mark OK...well hopefully it will get fixed sooner rather than later...I need my phone to work all day Oliver Perfectly understandable! I can guarantee that the Apple Engineers are working on it right now; my best advice in the long run will be to keep your device updated so you’ll get the patch at the point that it does get released! Otherwise, I really appreciate your patience!