Based on materials from android-softwares.com
Black themes for AMOLED – displays are loved not only because they provide great contrast and look great. It is a well-known fact that on this type of screen, completely black pixels do not consume any energy at all. This means that by putting a completely black wallpaper on the screen, you can reduce power consumption and extend the life of the phone from one charge. But how big are the savings at the end of the day? Surprisingly, it's not that big …
To find out how much black wallpaper can save power, three phones with AMOLED displays were taken: Samsung Galaxy S7 edge, OnePlus 3 and Nexus 6P. Then the brightness of their screens was set to the same level – 200 nits when displaying a picture with a white background. Under normal conditions, the brightness of the smartphone screen fluctuates around this value (if, of course, auto adjustment is set), 200 nits is an average. Finally, it remains to be sure that the experiment will not interfere with any applications in the background.
The test consisted of sequential setting of a series of 50 images as desktop wallpaper in order to determine how this would affect energy consumption. The average energy consumption over a total of 50 measurements means how much each device spends with a typical wallpaper. This result was then compared with that of a completely black wallpaper. Testing was also performed on completely white wallpaper to look at the power consumption of each unit in the worst case scenario.
The result table looks like this:
Now let's try to summarize the results in the most accessible way. Using the data, you can calculate how the power consumption of each phone drops when you set a completely black wallpaper. By dividing this result by the phone's battery capacity, you can see how much power is saved. Well, so that it doesn't look like speculation without real numbers:
- Galaxy S7 edge: Saves about 1.2% charge per hour on the home screen (best result – 3.2% if you change completely white to completely black wallpaper)
- On OnePlus 3: Saves 0.6% battery per hour on the home screen (4.5% best).
- Nexus 6P: Saves 1.4% battery per hour on the home screen (4.6% best).
Isn't that so much?
There is no denying the potential of AMOLED – displays in terms of energy savings. And also for this reason, a number of advanced users in an attempt to squeeze everything out of them use dark or black themes for their devices with such screens. And so geek-loved phones like the OnePlus 3 have a dedicated option built right into the user interface. Therefore, a number of smartwatches are actively using black in their menus – in order to compensate for their skinny batteries.
But as experimental data show, simply setting black wallpaper is not particularly effective at saving power. Yes, you get a few extra minutes of screen on. Maybe get even more if your device's battery is less than average, or if you consistently set your screen brightness to a high value. But in the case of a regular top-end device with a AMOLED display, the difference will be small, if not noticeable at all. And not only because the energy savings are disappointingly small according to the measurements, but also because most of the time on the phone we spend not on the home screen, but in games and applications.
What do you think? Did the result surprise you? Maybe you were able to achieve different indicators or do you prefer other ways to save battery? Share in the comments!