Hello all,
I've been suspicious of the power draw of the screen on the GNex, and so decided to figure out how much a difference brightness made.
This is to test the difference extreme brightness settings make to battery run times. Including text, browsing or having radios on will dilute the results. I'm only interested in the efficiency of the screen and its supporting infrastructure people!
Here's my testing method.
1. Charge phone to 100% using a PCs USB charging (should give a more full charge than the wall adapters quick charge, I think, otherwise no harm done). Leave attached to USB cable
2. Switch the phone into Airplane mode.
3. Switch off Auto Brightness and turn brightness to Max
4. Restart Phone. Leave it to settle for a few mins
5. Fire up "Just Pictures" and the image "TotalWhite.jpg" (attached). No other photos in the folder where it sits.
6. Disconnect USB charging
7. Start Slide show. Record the start time.
8. Every now and then (about 45 mins to an hour and bit) I quickly pop into settings and take a sneak look at charge level - don't want to get caught out!
9. Resume Slide Show.
10. Wait until the phone switches off, which is less than 2% charge
Now, it's not a quick process as I'm going from 100% Batt until auto shut off. So I'll be updating this post in installments. Today is the Max Daddy Full Brightness White image!
Full Brightness, White Image:
100% 00h00m
85% 00h39m
60% 01h53m
35% 03h08m
0% 05h00m
Pretty good I think!
Battery status stated that Screen was 91% and Android System was 9%. Screen on time was the same as the run time. It never went off.
There's a heavy set of disclaimers to go with this though: The White Image isn't quite the right aspect for it to display across the full amount. Check out the image "White Full The Phone.jpg" - it's pretty close though. Just Pictures isn't so full screen that it takes over the Android buttons - Anyone know a 100% full screen picture view BTW? Between the point where it comes up with "Please connect your charger" (15%) and 6% it said that message over the White image and partly dimmed the screen - I'm at work and was in the middle of something when it happened.
Minimum Brightness, Black Image:
100% 00h00m
85% 01h26m
82% 02h05m
18% 08h54m
0% 10h47m
Battery status stated that Screen was 85% and Android System was 16%. Yes, that's 101%, but there you go... Screen on time was within a minute of the run time.
Again, some notes on the testing: From the "connect your charger" point (i think 15%) to 8 % it had the message on the screen. Just before the end I accidently touched the screen and ended the slide show for up to 15 minutes and the screen went off. Switched it back on and it was at 2%. It then lasted something like 30 mins before auto shutdown. Black isn't Black! check out my the photo "Black Dim The Phone.jpg" - ignore the strange black specs, it was 1 seconds exposure at F1.4, with the camera facing down - think there's some crap in my camera body/lens.
Minimum Brightness, White Image:
100% 00h00m
0% 10h20m
Again, Battery status stated that Screen was 85% and Android System was 16%. That's the same as when I ran it on Min Brightness, Black Image...
Maximum Brightness, Black Image:
100% 00h00m
0% 10h52m
Battery status stated that Screen was 90% and Android System was 11% (again 101% also probably due to some rounding going on). Screen was on 100% of the time, Android OS was awake for 100% of the time, CPU time 23 Seconds
Overview:
Maximum Brightness White Image: 5h00m
Maximum Brightness Black Image: 10h52m
Minimum Brightness White Image: 10h20m
Minimum Brightness Black Image: 10h47m
Well, well, what's happened here? Maximum brightness with a black image scored the longest run time - unbelievable, right? Yeah pretty much: On the minimum brightness black run I did check the battery stats a few times. The black image run had a greater Android OS drain (11% vs 9%) compared to the white image. As I switch the phone off in preparation for the test it's possible I inadvertantly bump charged the phone. In addition to this, I was trusting the phone a lot more in this, the final test and didn't check the battery status near the end, so perhaps drawing a lower current happily sitting there doing nothing other than displaying a blank image the phone managed to syphon off the last dregs of power, as opposed to spending CPU time with me rummaging through the settings screens for battery stats. Let's put it all down to being in the margin of error and consider the Black images to have the same run times, despite the Android buttons blazing away on Bright (but they aren't many pixels).
Conclusion:
Back to my original concern, that the screen was abusing the battery more than necessary. I'm mostly happy with the outcome - Black bright and dim screens draw substantially less than a very bright white screen on this phone, as it should. It's surprising to see that on dimmest setting the white screen got so close to the run time of the black screens. It's producing a lot more light than either black screen. It's drawing c5% more power than the black screens, but I would expect a lot more. I'm guessing that the circuitry to run the Screen and the small amount of power used to make the "Black" OLEDs glow dark dark grey draws only a little less than the white screen.
And that's a shame. I wanted to run an app such as "Off-Clock" to have a clock on the screen like the Nokia N8 used to do, but i'm thinking this will eat the battery in 10 hours 20 minutes. Only one way to know for sure....
My initial annoyance that Black never is actually Black whilst the screen has faded. Many of you good folks have pointed out (and after more Googling) that all OLED screens have this, although the reason for it isn't clear. It's either to ease the transition from black to lit by having the LED at the threshold already, power seeping into the circuit somewhere or something else. Who knows, maybe we'd get better run times if the screen was on full brightness but used PWM or a fast strobe to show a dimmer image!
That's all folks, discuss, and remember - continue testing...
I love you for doing this. Please don't stop.
Some tidbits: The whole phone was warm, front and back. Not scary hot, but like a nice hand warmer. The screen shots were actually done after I connected the charger and restarted the phone. You'll see the graph shows it starting to charge, but all the stats are for when it was last on the battery - in the test.
Thanks for testing this.
How do you define min brightness?
The black color, do you mean #000000 hex color code?
That will last days!
Sent from my Nexus S using XDA App
excellent thread that's it's about screen time on no idle time
gogol said:
Thanks for testing this.
How do you define min brightness?
The black color, do you mean #000000 hex color code?
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Not too scientifically - I made it black in MS Paint. It's a JPG. I tried it out in portrait and landscape on full brightness and I can't see the edges of anything on the screen, so it's as black as the rest of the black in Gallery. If you have a better way, then I'd gladly take a 16x10 black image if you think it is more black.
Min brightness will be using the brightness slider in settings. I haven't rooted the phone so don't see any way to get it lower. I tried the app "Dimmer" but it's the same brightness as far as I can tell as min setting. Also I figured the min setting was relevant to more users than something they can't easily get to (or probably see on screen!).
Do you have any suggestions? I want to root, but my home PC can't see my GNex. It's being a pig about it and I haven't got Broadband ATM... Hope to root as soon as I can.
Just a quick input. If you just show a picture for 5h how does the cpu perfom in this time? Isn't it really bored?
In addition if you switch it to air plane mode it doesn't use any power for transmitting a signal. I know this point is really tricky due to the fact that not everybody receives the same signal strength.
Isn't there a more realistic way to test it? Like a combination of stability test and the white picture?
Or a slide show with specific pictures, for example a picture with lots of green, one with a lot of red, one with blue, one with white and one with black?
I really like the idea but if we could create something like a standard which tries to simulate real usage that would be great for future testings.
So that we could say something like:
Galaxy Nexus with Vanilla Android -> 5h with XDA battery benchmark
Galaxy Nexus with CyanogenMod 9 -> 5.3h with XDA battery benchmark
We could compare different settings and see how good they perform based on a "standardized" procedure.
Hmm is this probably a bit too much?
I like the idea of a standardized battery procedure for XDA.
Only thing is, i feel like just web browsing would give a better idea, mostly white website sites and it uses data and CPU/GPU still to give real world usage results.
Nebucatnetzer said:
Isn't there a more realistic way to test it? Like a combination of stability test and the white picture?
Or a slide show with specific pictures, for example a picture with lots of green, one with a lot of red, one with blue, one with white and one with black?
I really like the idea but if we could create something like a standard which tries to simulate real usage that would be great for future testings.
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Hi Nebucatnetzer, I get what you're going for and think it would be a great test. My original goal was just to see how much of a drain the screen was. I used it on Airplane mode as I do not want to have any other drains diluting the result. As you say, signal strength changes, and so this becomes an uncontrollable variable. I'm only showing a white image as it's the most uniform full power test of the screen I can think of. As the display is RGBG, maybe a greenish white would draw more, but I can live without that - web pages are predominantly Plain White and Text in ICS is white.
I actually think that 9%/10% drain for Android OS may be a bit high for 5 hours. I think Just Pictures may be the cause for it as it does every minute change the image in a slide show... to itself...
pewpewbangbang said:
I like the idea of a standardized battery procedure for XDA.
Only thing is, i feel like just web browsing would give a better idea, mostly white website sites and it uses data and CPU/GPU still to give real world usage results.
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It was one of the things which annoyed me the most here. Everyone says he has the ultimate tweak to save juice but you never really could measure it.
We probably have to skip the data part due to asimilar signal strengths.
And it would be really cool if we could find something which works for every phone.
pewpewbangbang said:
i feel like just web browsing would give a better idea, mostly white website sites and it uses data and CPU/GPU still to give real world usage results.
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Hi! I'm not trying to do a real world test as such. I'm trying to find out how much of an impact a white screen has compared to a black screen. I have a suspicion that the Black screen will draw more than it should do. I've been using my phone on Auto Brightness and at night, min brightness and have found the screen is caning the battery. There's more to the screen than the AMOLED - there's also a MIPI Framebuffer controller, plus whatever interfaces that has to the rest of the phone.
I'm aware that ICS and the other internals of this phone seem quite efficient, so any savings I can make on the screen (which really does suck the juice) should translate into big run time gains... Surely...Right?
If it turns out that there's very little different in battery life between a Black screen and a white screen, then I'll crank up the brightness to revel in its retina destroying beauty. If there is a difference, then i'll stick with my black homescreen background....
The black screen shouldn't draw any power virtually as long as its truly black. SAMOLED functions where black doesn't turn the pixel on so no energy is used. I think the black test has been done by someone, you can probably google it.
We we aren't criticizing you specific we just hijacked the thread a bit sorry for that .
Nebucatnetzer said:
We probably have to skip the data part due to asimilar signal strengths.
And it would be really cool if we could find something which works for every phone.
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would be good if someone could make a benchmarking program which pumps out signals in a set pattern on all devices at set frequencies and at a few different power levels. It would't need to wait for a response from any cells or WiFi routers, just talk to itself and only itself. Maybe this would need too low level access to work, below root.
Then you'd have your predictable Radio part of the test. If it's even possible.
pewpewbangbang said:
The black screen shouldn't draw any power virtually as long as its truly black. SAMOLED functions where black doesn't turn the pixel on so no energy is used. I think the black test has been done by someone, you can probably google it.
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Well, I hope a black screen will draw considerably less. We shall see. Or it will be a revelation... Or everyone will get to witness me finding out that my phone is defective. Hahaha... oh...god I hope not...
I may run the black test overnight. It should last the night. If it doesn't I can always hook it up and check the last "On Battery" status as I did earlier. Then I can run two tests tomorrow!
Davidsmonkeyroost said:
would be good if someone could make a benchmarking program which pumps out signals in a set pattern on all devices at set frequencies and at a few different power levels. It would't need to wait for a response from any cells or WiFi routers, just talk to itself and only itself. Maybe this would need too low level access to work, below route.
Then you'd have your predictable Radio part of the test. If it's even possible.
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This sounds more than difficult. Not a clue how one could do this.
As soon as I have my device I'll probably start a thread where we can think about a standardized (what a stupid word) battery test.
Curios how your second test goes.
Instead of the black screen test, amoled screen, you could do a white background with black text. This would give better overall real world stats.
Text generator http://www.lipsum.com/feed/html
Second test - black on lowest brightness - is underway.
Some bad news, which you may already know about: Black isn't black. It's very dark, but the phone isnt switching all the pixels off. I took a photo with my SLR in the dark but can't upload at the moment, will upload tomorrow.
Just took a sneaky look at the stats.
85% 01h26
The draw is 85% screen and 16% Android OS. Yeah, I know they don't add up, but that's what it says.
So far, the draw is higher than I expected for lowest settings with a black image. Odd. The phone isn't warm though, like when the screen was showing a white, max brightness image. It's cold.
Sure hope it doesn't start moaning about running flat whilst i'm asleep...
Last check before I go to sleep: 82% 02h05
Same split of 85% screen and 16% Android OS. Who says percentages have to add up to 100?
Davidsmonkeyroost said:
Last check before I go to sleep: 82% 02h05
Same split of 85% screen and 16% Android OS. Who says percentages have to add up to 100?
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Most likely rounding bug.
So I've always used my phones with automatic brightness, but it seemed like this one would always be really low. The only time I would see the brightness change at all was when I'd take my phone out in the day when it was sunny. So I decided to switch it to full brightness on all the time and haven't really noticed a big difference in battery life. Plus with such a great display it looks so much better with the full brightness on. Any of you tried this and notice a big battery drain??
Sent from Flip's SGS2
Im the opposite of you. If i have my brightness pass mid, my battery will be drained in no time. So i am forced to use low. I cant even use Auto Adjust, because that will also use a lot of battery. Mid and higher, my battery drainage will be around 59%-65%
For me full brightness really kills my battery. I I used to do full brightness but after going on my quest to improve my battery life I ended up sticking with ~50% brightness
Sent from my SGH-T989 using Tapatalk
The display is (generally) the biggest drain on your battery, so adjusting the brightness level accordingly definitely has an effect one way or the other. If I'm not in direct sunlight I leave my brightness very low, usually around ~15-20%
One of the biggest battery savers I found was a new watch my wife bought me. No more turning the display on/off throughout the day just to see what time it is
I was checking out the Galaxy S3 at my local AT&T store and noticed the display seemed dim compared to my GS2 but just figured it was the store lighting but after reading this review from Cnet I guess it might have been the GS3..
i would think having to crank up the display brightness to higher levels then need be on a GS2 would cause some considerable battery drain.
What are you guys finding coming from the GS2?
Captpt said:
I was checking out the Galaxy S3 at my local AT&T store and noticed the display seemed dim compared to my GS2 but just figured it was the store lighting but after reading this review from Cnet I guess it might have been the GS3..
i would think having to crank up the display brightness to higher levels then need be on a GS2 would cause some considerable battery drain.
What are you guys finding coming from the GS2?
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I didn't like the auto-brightness so I just manually do it. Most of the time I leave it at 100% and I have excellent battery life. But you can install a toggle or widget to adjust brightness. Also, there's a battery save option that lowers screen brightness, which might also be coming into play.
You're right it is not as bright. Especially compared to a Vibrant. It is however very usable. Most of the time I have mine turned down to either 50-75%
the-Mike_D said:
You're right it is not as bright. Especially compared to a Vibrant. It is however very usable. Most of the time I have mine turned down to either 50-75%
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Wow.. If I left my GS2 at 100% or even 75 I wouldn't make it through the day on a full charge.. Not even close.. Kind of worries me now..
I get over 3 hours of display time a day now, what are you guys getting with the GS3 set at 100% and Mike's 50-75%?
Sent from my GSII w/ICS SHOstock2
Screen at 75% 12 hours since charged. 2.5 hours of screen time. 30 minute phone call. 45% battery left.
Sent from my SAMSUNG-SGH-I747 using Tapatalk 2
Since the screen isn't as bright as the GS2, 50-75% is probably what the GS2 did at 30-50%.
I keep mine at around 65% and usually get around 4-5 hours of screen on time per day. The phone easily lasts the whole day with medium usage.
Even at 65% my phone can still be easily seen in sunlight.
Nice.... actually sounds like the GS3 has better battery life then the GS2!!! Even with the display cranked up more then I presently use on my GS2...
Sent from my GSII w/ICS SHOstock2
Is anyone else noticing that the screen flickers when it dims down after the 15/30 seconds? I'm barely noticing this on mine now and its somewhat irritating..
Sent from my SAMSUNG-SGH-I747 using Tapatalk 2
Auto is too dim for me so i set it around 79%. Higher brightness hurts my eyes but maybe I just need to get used to it?
Sent from my LG-D851 using XDA Free mobile app
I turned off auto and set the brightness to 100%. I love a bright screen. So far 17 hours on battery, 2 hours screen time, and still at 50%. Good enough for me.
I need better
Sent from my iPhone using Tapatalk
cnotes2019 said:
I need better
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Turn off the lights.
I keep it always on 100%. Only when I need to save the battery I lower it.
Would love to get more input.
I simply use auto brightness. Bright screens look better but they strain my eyes too much.
I keep it at 50% and thats super bright for me... Keeping it 100 sounds insane
Sent from my LG-D851 using Tapatalk
Apparently I'm in the minority so far. I hate screens that are too bright for the setting they're in. I keep mine at absolute minimum (0%?) unless an increase in ambient light makes it hard to see. Then I increase it as little as possible until it's at similar visibility as it was before the ambient light increase.
i keep mine at 50% also, i could see doing 60% if i really needed it but anything over that would be overkill IMO.
I use auto
auto 100%
I use Lux app. Check the PlayStore and see if it might work for you.
You guys no you can adjust the contrast.
Sent from my: T- Mobile LG G3
80% most of the time. I adjust when/if I need to.
Usually <50% indoors and >70% outdoors. The best way to make it learn what you like is to use LUX app.
Running your pixel 2 xl on auto brightness is good or bad? Does it use more or less battery?
dieselhazza said:
Running your pixel 2 xl on auto brightness is good or bad? Does it use more or less battery?
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It doesn't use much battery compared to Adaptive Brightness off unless you keep your screen at something low like 10% or less the whole time.
dieselhazza said:
Running your pixel 2 xl on auto brightness is good or bad? Does it use more or less battery?
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I've always, even with previous phones, used manual brightness. Partly because I am usually happy with brightness to be kept at, for this device, at 15% and if I need to adjust Ill use Brightness Control. I also feel that battery life must surely be better as the sensor isn't constantly being used to gauge how bright the screen should be and lastly always found autobrightness to increase/decrease the screen brightness randomly, e.g. Say in my living room and it'll just increase/decrease slightly.
So ultimately I'm very happy just to manually adjust
cd993 said:
I've always, even with previous phones, used manual brightness. Partly because I am usually happy with brightness to be kept at, for this device, at 15% and if I need to adjust Ill use Brightness Control. I also feel that battery life must surely be better as the sensor isn't constantly being used to gauge how bright the screen should be and lastly always found autobrightness to increase/decrease the screen brightness randomly, e.g. Say in my living room and it'll just increase/decrease slightly.
So ultimately I'm very happy just to manually adjust
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Mine is set to.20% with auto brightness enabled. At most times it hovers very close to 20%. I guess if i disabled auto brightness i will get better battery life. At the moment i average 7 hrs SOT.
So what do you achieve in terms of SOT at 15% brightness
dieselhazza said:
Mine is set to.20% with auto brightness enabled. At most times it hovers very close to 20%. I guess if i disabled auto brightness i will get better battery life. At the moment i average 7 hrs SOT.
So what do you achieve in terms of SOT at 15% brightness
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I've been averaging around 6hrs (just need to stay on one rom long enough haha)
cd993 said:
I've been averaging around 6hrs (just need to stay on one rom long enough haha)
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Ha!!....like that's gonna happen! Mr. Flash Master! ???
cd993 said:
I've been averaging around 6hrs (just need to stay on one rom long enough haha)
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I'm just running on stock firmware and happy with the battery performance.