1 Tweak Display Settings
Changing the settings on the iPhone X’s OLED screen can yield two days of battery life, or even more by drastically minimizing your screen’s power consumption. Note: This is a more drastic battery saving tactic, that probably won’t be appropriate for everyday use.
1. The first tweak you can make is switching on Grayscale, which cuts power use by depicting images in shades of gray. You can do this by performing the following steps:
Go to Settings > General > Accessibility > Display Accommodations > Color Filters > Grayscale.
2. The second thing you can do is activate Smart Invert Colors, a new iOS 11 feature that inverts all colors on your interface while leaving app icons, graphics, and photos mostly unchanged. Just follow these simple steps:
Fire up Settings > General > Accessibility > Display Accommodations > Invert Colors > Smart Invert.
Take note, however, that if you are going to invert colors, you’ll want to apply an all-white wallpaper instead, which will turn black once you enable Smart Invert Colors.