Usually guides to increasing the battery life of phones and tablets involve impractical advice like disabling Wi-Fi, turning off all background activity, killing notifications, and other “tricks” that make using the device pointless. After all, you could gain almost infinite battery life simply by never switching your iPhone on.
This piece of advice is just like those. It involves turning off the color on the iPhone X’s OLED screen to save juice. However, this tip actually turns out to be pretty useful, and makes the iPhone look totally badass, too.
How OLEDs work
iPhone X OLED display + grayscale + smart invert colors + low power mode = ridiculous battery life. pic.twitter.com/vXV821jXrO
— Neil Hughes (@thisisneil) November 5, 2017
This trick was discovered by tech journalist Neil Hughes, who posted the results on Twitter. He calls it Unofficial Battery Saver Dark Mode, and it takes advantage of a trait unique to OLED screens. A regular LCD screen comprises a backlight, and a grid of colored pixels. The pixels change to create an image, and the light shines through those pixels, like a projector through a strip of movie film.
Because the backlight is always on whenever the screen is activated, even if the screen is showing mostly black, it wastes power. An OLED screen only lights up the pixels it uses, so displaying black uses less power than showing white. This may be the reason that Apple now supplies a pure black wallpaper for iPhones.
Enable the iPhone’s ‘Hidden Dark Mode’
The first step of Hughes’s method is to switch on the iPhone’s Smart Invert Colors mode, aka the hidden dark mode. This turns white to black, making most web pages, for example, appear with white text on black. It’s handy for late-night reading, but on the iPhone X, it also saves battery power. The “smart” part in the name refers to the new-in-iOS 11- trick that leaves images (and icons etc.) alone when inverting colors, so they look normal. To enable the hidden dark mode, check out our how-to.
Step 2 of the Hughes Method is to turn off color altogether. This takes advantage of another OLED quirk — different colors use different amounts of power to display. The thinking goes, then, that eliminating all color will reduce battery consumption still further.
‘Ridiculous’ battery life
Writing of his experience in using this trick, Hughes says that the battery life is both “Ridiculous,” and “Great.” A proper, extended test will be needed to see how well this really works. Nobody will have been able to do that yet, though, because the iPhone X is just too new, and they’re all still grinding through battery-intensive tasks like scanning your photo library.
If you want to follow along with Hughes’ tip, the best way to do it is to assign grayscale and Smart Invert Colors to a triple-tap of the side-button on the iPhone X. Then, when you triple-tap it, a dialog box pops onto the screen offering both of these options. To toggle both, you need to do the triple-tap twice. If you find yourself suddenly low on battery, and the built-in low-power mode isn’t cutting it, then you can quickly enter “Unofficial Battery Saver Dark Mode.”
To switch this on, go to Settings>General>Accessibility>Accessibility Shortcut, and check the listings for both Color Filters and Smart Invert Colors. You may also have to go to Settings>General>Accessibility>Display Accommodations to make sure it turns grayscale and not some other color (this option is meant for colorblind users). Now, when you triple click the home button, you’ll see this box:
That’s where you toggle these two options. You may even like to do this on a regular iPhone screen, because it looks pretty badass in B&W, and with a dark background. Does it save a lot of battery? Maybe. Even if you don’t like this trick, you might consider the all-black wallpaper, because that really will save some juice.