Google and Android Windows Phone - 04 February 2011
Author: Danny Lam

WP_000005We’ve all been told that OLED technology is more efficient and less power hungry than tradition LCDs. This is because OLED displays only emit light from the cells that require it, instead of a backlight consuming constant energy, regardless of what’s being displayed. This allows pixels to be turned off when displaying black colors, which saves power and allows for darker blacks when compared to their LCD counterparts.

Most of you may also be aware that OLEDs aren’t more efficient in every scenario, but for those who can’t differentiate a “geek” from a “nerd”, they’ aren’t.  For example, LCDs consume a constant amount of power, regardless of the colors being displayed on the screen, but when displaying white backgrounds, OLEDs typically consume more energy than LCDs, however the opposite is true for black colors.  Since I unlocked the Engineering Mode for my Venue Pro, I decided to use it to see the difference in power drain between having white and black backgrounds.

Both pictures were taken while the phone was in airplane mode to prevent extraneous downloads/updates from causing excess power usage. I repeated the tests a few times WP_000002 (2)to make sure these results were consistent, and they were.  As you can see, with the white background, the Venue Pro is consuming 537mA while the black background is sipping only 283mA.  That’s nearly double the power consumption of the black background! In addition I checked the values with airplane mode off, and the power levels did not rise in any significant amount.  Windows Phone users, like me, lack the simplicity of checking which aspects of their phone uses the most power(like Android can), but suffice it to say that the display is a big chunk of your power usage.  If you use your phone a lot, using a black background instead of a white one could significantly increase your battery life.









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(6) Readers Comments

  1. i am always aware of that (white bg’s are less energy efficient than black’s – same thing on monitors too) i just hope app developers are all aware of it and give us the options to flip the bg color. better yet, android should make that part of the Honeycomb feature – the ability to force black bg with grey text.

  2. Jeez, even 283 mA is a big battery draw. What’s the battery size on the VP? Is it 1250 mAH, or something like that? You’re only going to get 4.5 h of uptime with that draw. On my fuze, with the backlight at 50%, I have a draw of ~115 mA.

  3. White on AMOLED actually draws more power than white on most of the other standard displays. From what I’ve heard, it also decreases the life of the display

  4. It doesn’t matter- the black is so black and the white is so white I don’t care how lngo it lasts!:) I do use a black theme and I think the battery life on my Focus is solid. I haven’t come close to having an issue with it. Interesting though, that white is twice the draw…

  5. @FarTed: The battery is 1400mAh. Forgot to mention that the backlight was set the “high” and that the Venue Pro has a 4″ inch screen so it will use a decent amount of power.

  6. Nice post! It’s surprising how many people don’t know about this power difference and still complain about poor battery life. You can search the web and images using Black Google Mobile at http://bGoog.com and it looks great. Every bit helps!