It is about "AMOLED: Black wallpaper = Battery saved?"
As I promised, I have done a simple non-scientific experiment:
(1) At maximum brightness, screen on for 15 minutes
- Default wallpaper will consume about 5% (from 36% down to 31%)
- Pure black wallpaper will consume about 3% (from 30% down to 27%)
(2) At brightness = 20+%, screen on for 15 minutes
- HTC Black wallpaper will consume about 2% (from 26% down to 24%)
- Default wallpaper will consume about 3% (from 23% down to 20%)
- Wifi OFF
- Mobile network OFF
- GPS OFF
- Bluetooth OFF
- Screen at home screen with default HTC clock (white background with weather)
* The HTC Black wallpaper is available by default when you choose HTC wallpaper. It is not pure black, but it is still black
So, conclusion, using black background will save you battery life. The above experiments were conducted at 15 minutes each and you immediately see the difference.
I would say at low brightness, 20% - 25%, you will get 1% up to 2% battery saving per 15 minutes, let say 1.5% per 15 minutes. For 1 hour you will get about 6% battery saving.
Of course, of course, I know, who will stare at the home screen for 1 hour? But who knows? In the course of the whole daily use with the phone, how long do you think you scroll left and right in the home screen?
Or imagine you are browsing XDA forums a lot, every day. It would be better using the Android XDA app by Tapatalk because it uses black background instead of browsing via web which uses bright yellow background!
Also see how the brightness affect the battery life. My eyes is happy with about 20+% brightness
Again, this is non-scientific experiment, but it should give you rough idea how much your amoled screen uses battery power
PS: Yes, I have nothing to do this afternoon Too much time, He he he ...