Dark mode on devices may not save much battery life, study says

Dark mode has been marketed as a battery-saving setting on smartphone and laptops, but a Purdue Univeristy study suggests otherwise.

A new study reveals that dark mode doesn’t necessarily save much battery life. But there are a few ways that users can take better advantage of the feature, Purdue University researchers say.

Dark mode setting has become an increasingly popular battery-saving feature in smartphones. But the option is unlikely to make a big difference in extending a phone’s battery life as promoted by both Android and iOS, according to a study by Purdue University.

(Subscribe to our Today's Cache newsletter for a quick snapshot of top 5 tech stories. Click here to subscribe for free.)

A team analysed six most-downloaded apps on Google Play - - Google Maps, Google News, YouTube, Google Calendar, Google Phone and Calculator app - - to find out how 60 seconds of mobile screen activity in dark mode affected battery life. The team also looked at Apple’s iPhone X for data from iOS device .

They concluded that switching from light to dark mode saved only up to 9% power on average for different OLED smartphones at 30-50% brightness, and said the power efficiency depended on the brightness of OLED screens.

“The percentage is so small that most users wouldn’t notice the slightly longer battery life. But higher the brightness when switching from light mode to dark mode, the higher the energy savings,” they noted in a study titled ‘How much battery does dark mode save?: an accurate OLED display power profiler for modern smartphones’.

Using a higher brightness in dark mode draws the same amount of power as lower brightness in light mode, making it easier on the user’s eyes, the team noted. This indicates that although dark mode may not be as battery efficient as expected, it does have some benefits.

Android and Apple smartphones provide options to see how much battery each app consumes, but they do not provide an account of the impact of dark mode, the study said.

The team has also developed a tool to calculate battery power consumed by an app in Android devices. It will be made available to app developers and platform vendors by the end of the year.