Apple’s iOS 11.1 drains battery faster than you can say dead battery. Okay so a bit of an exaggeration perhaps but as many iPhone users have experienced, iOS 11.1 shortens battery life significantly among other things.
On my iPhone 5s for example even when using low power mode I find a 20% battery drop in just a few hours on standby! In my opinion this is unacceptable especially when previous iOS versions lasted much longer. Maybe the culprit is iOS 11’s new Wi Fi auto on feature. Whatever is causing this battery drain it’s annoying and I hope Apple fixes it soon.