Battery life on the iPhone has never been phenomenal, and the iPhone X, unfortunately, doesn’t change that much (review in the works!). However, the iPhone X does bring with it a new tool to improve battery life. First, a little background. The iPhone X features an OLED display. There’s a few huge differences between the old screen, the LED, and the new OLED display, but the lighting on OLED displays makes the biggest difference for battery life. For an LED or LCD display, the whole screen is lit up. A few big, bright lights are on all the time, shining through the pixels to light them all up equally. OLED screens light up each pixel individually. This means the whole screen doesn’t have to be lit. Not only does this improve contrast on the screen, it drastically reduces the amount of electricity the screen uses.
You can take advantage of this now if you have an iPhone X. A wallpaper that’s all or mostly black would use less electricity than a colorful one. Even a grayscale display would have more dark pixels. There’s a secret super-low-power mode in iOS, one you can unlock by using invert colors and grayscale—features already built in to iOS—to increase the black pixels on the display, and therefore us a lot less energy. How much less? One tester saw a 60% improvement over the stock settings! You’ll have to change a few settings to make switching back and forth between regular usage and the super saver mode, but once you do, you’ll have a new way to save hours of battery life. Here’s how you can do that yourself in just a few easy steps.
The method of using inverted colors and grayscale filters to improve battery life isn’t new. Android has been doing this for years, as they’ve been using OLED displays for some time now. While Apple didn’t think OLED displays were good enough for the iPhone (they lacked color accuracy), now that Apple has designed their own, iOS users can get in on the battery life savings. Many Android phones already have a super low power mode that makes the screen black and white, and some have always-on displays, that light up only enough pixels to tell the time. Fortunately, those of us on iOS can now do the same.
This is the shortcut you’ll have at the end of the guide below. Turning these on will save you drastic amounts of battery life.
You’ll have to venture into accessibility features. What we want to do is enable a quick way to toggle Smart Invert and Grayscale. Now, a word of warning. Turning on Smart Invert will disable True Tone and Night Shift. You can re-enable them when you’re not in desperate need for a little extra battery life though.
First, we have to tell iOS that when you adjust the color of the screen, you want it going to grayscale. Go to General > Accessibility > Display Accommodations > Color Filters. Here, turn on the switch, and select Grayscale. Then, turn it back off. We’ll add a shortcut for this later, but we had to tell iOS we need it to alternate between gray and normal when you hit the shortcut button.
Next, we’ll add the shortcut to the screen lock button (alternatively, you can add a shortcut to Control Center).
Start off by going to General > Accessibility. Here, you’ll have to scroll all the way to the bottom, the the Accessibility Shortcut. Tap that and select Color Filters (which you just set to grayscale) and Smart Invert Colors. Now, triple click the lock button. A dialog should pop up at the bottom. You’ll have to triple click for each option, but, by doing this, you’re just a few taps and 6 clicks away from a screen that uses considerably less electricity. You’ll see drastically longer battery life now.
You can choose to only enable Smart Invert Colors, which might be enough for you, but I found grayscale makes it feel less jarring. On top of that, displaying colors does take more power than displaying shades of gray, so this option will help you sip every bit of juice out of your phone. With this new power saving feature handy, and in combination with Apple’s own low power mode (which you can add to Control Center in iOS 11) your phone may be able to last you an entire weekend without a power source, if you need it to. iPhones still don’t have fantastic battery life, but with the help of this tip, you can go days with a reliable phone by your side.
Source: Neil Hughes, AppleInsider: “Extreme test shows OLED iPhone X with ‘dark mode’ saves nearly 60% battery over 3 hours.”