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I started wondering about this when I realized most websites I visit have white backgrounds, and I know that the screen is usually responsible for most of the battery usage. Since I can't change the background in those sites, I might at least switch my wallpaper to a black one.

Most (all?) phones need back-lighting to brighten the screen when needed. Since that back-lighting consumes battery, is it correct to state that a white screen consumes energy at a faster rate than a black one? (assuming the same brightness level in the settings)

I'm assuming that a white screen needs stronger back-lighting, but I don't know if it's the case.

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Good question. I'd hope that my OLED screen uses less power with a dark image than a backlit screen.. but would love to see some figures. –  pelms Jan 22 '11 at 0:52
    
Wow, I chuckled when I first read this, but this has turned into a pretty interesting question. –  shambleh Jan 22 '11 at 1:29
    
Some devices (like the Galaxy S) have an option under Display settings labelled: "Power Saving Mode: Save power by analyzing image and adjusting LCD brightness". This seems to suggest that the sAMOLED screen is adjusting it's brightness depending on the image brightness, and getting a noticeable enough benefit on dark images to make this worth being a standard option. –  GAThrawn Jan 23 '11 at 22:29
    
There's an app called screen filter which keeps the brightness down for the purpose of saving battery life on LED based displays. –  barrymac May 31 '11 at 17:14

4 Answers 4

up vote 36 down vote accepted

On OLED, AMOLED and Super AMOLED screens: Yes

LCD screens: No

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From what I can see in your seconds link, dark backgrounds do actually reduce power consumption of LCD screens if they use IPS technology. Like the one in HTC One X, I believe. –  Pius Sep 2 '12 at 14:51
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@Pius The reduction listed in that table (~4%) is negligable compared to the the 100% drop between white and black on AMOLED screens. It is interesting though. This article suggests that IPS LCD use less energy than AMOLED screens on screens that display approx 33% white or more. –  Matt Sep 7 '12 at 23:17
    
VERY interesting article. Thank you for sharing. –  Pius Sep 9 '12 at 9:38
    
For OLED, AMOLED and Super AMOLED, is it just complete black pixels that consumes battery much less because light is turned off? Or is it also dark grey pixels too that consumes considerably less energy than white pixels? –  Jisang Yoo Nov 13 '13 at 15:35

This depends on the screen technology.

For instance, (it was said that) Android 2.3 Gingerbread has dark theme since Google's latest flagship device Nexus S uses (Super) AMOLED display which consumes less energy when displaying dark color since AMOLED produces its own light and darker color emits less photons. Contrasts with LCD display which uses a backlight (a fixed number of photons) and the LCD crystals filters those colors it needs. The crystals on an LCD displays though, actually consume slightly less power when displaying white since it takes more power to strain the crystal to block more light.

Screen color does not affect the backlighting. There are certain display technologies in TVs that tries to give dynamic backlighting by dimming the screen when displaying darker image. I'm not aware of any device that actually ships with that type of screen though.

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Android 2.3 uses AMOLED? Isn't AMOLED a property of the phone? –  Malabarba Jan 22 '11 at 1:02
    
@Bruce: whoops, I meant to say Nexus S, sorry about that. Fixed. –  Lie Ryan Jan 22 '11 at 1:22

If your screen has an older standard lcd then this doesn't help at all. The backlight is still shining behind all those darkened pixels. You just can't see it.

If you have oled, amoled, super amoled, LED lcd, or I think even plasma then it does help to darken the screen because the light is generated specifically where it is needed.

BTW there are fire fox plugins that reformat whatever page you are on to be dark. I don't remember the names, but I needed it when I was living in a studio apartment with my girlfriend and I was up all night on my computer while she was trying to sleep 20 feet away in the same room.

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Hey, I just ran a load of test to figure this out. They are vaguely scientific tests! I figured out that I was saving 20% battery by switching to dark wallpaper and dark themed apps. Have a look through my write up, you should be able to work out the saving on your phone:

http://blog.stevemould.com/phone-battery-save-black-wallpaper/

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Your "report" provides more detail information on this question than any of the other answers with higher votes. It's a shame that some people just upvote the answer at the top. Nice research - thanks for your time doing that and writing it up. –  Bernhard Hofmann Feb 9 '11 at 7:58
    
Thanks for the tip... Current Battery usage is criminal and had been searching for an answer on the net to extend the battery life of my S.. –  Shaunak Feb 9 '11 at 14:44

protected by Matthew Read Apr 29 '12 at 6:10

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