But the researchers said that switching from light mode at 30-50% brightness to dark mode only saves between 3 and 9% of power on average for all the tested devices.
However, the study found that users would see more significant power savings if they went from a light mode at high brightness to the dark mode.In fact, it noted that switching from a light mode with 100% brightness (as you might expect when outdoors in the sun) to dark mode could save 39 to 47% juice.
So it stands to reason that you’d see higher gains switching from a light mode at super-duper high brightness to a dark mode than switching from a light mode at moderate brightness.