Does dark mode really result in better phone battery life? Yes, in this scenario...
It's become a staple in best phone battery life tip roundups - use Dark Mode for the interface if available - as OLED displays consume the most energy when showing white, and none when showing black, as the diodes are completely turned off then.
Enter a study that tried to determine exactly how much battery would you save by running dark backgrounds and wallpapers on your phone with OLED display (most phones nowadays).
researchers from Purdue University tested a number of popular apps - Calculator, Google Calendar, Google Maps, Google News, Google Phone, and YouTube - on everyday phones with stock or nearly stock Android overlay such as the Pixel 2, Moto Z3, Pixel 4, and a Pixel 5.The
How much battery does Dark Mode save?
Well, the team found out that when the display works at average brightness levels, 30%-50%, the dark mode power consumption savings in the respective apps was rather negligible at up to 9% reduction in power draw.
Put the phone in automatic brightness, however, and go outside on a sunny day, and the screen brightness gets an immediate boost to the highest amount possible. Needless to say, in that scenario the power savings from using the phones in dark mode where significantly higher, to the tune of the whopping 47% on average.
Phone display battery consumption on dark mode
Yep, that means that on the beach your phone may last almost twice as long in dark mode than if you don't use this setting. This result is perhaps not surprising for those who know that an OLED display's power consumption is not linear, and showing white on full brightness is the worst of worst scenarios for the level of its power draw that will kill your battery in no time.
According to the research team, their tailor-made tools are behind the accurate OLED display power consumption depiction both in and out of Dark Mode:
The researchers are promising to open source their enhanced Android Battery+ tool to better suit the needs for measuring the unique power draw realities of modern OLED displays, and will try to integrate it in AOSP going forward