Develop Bugs

Tips to extend battery life with ICS

All,
In case you haven't noticed, the battery life of the Nitro HD is kinda bad... Then, when you add ICS into the mix, it gets worse.
When i first flashed the Leaked ICS ROM, I noticed that I was only getting about 8 to 9 hours of battery life with very light use. So, I endeavored to find a way to extend that time without buying an expensive extended battery.
Here are my findings:
GPS
Settings > Location Services
Now we all like the convenience of being able to pull out our phone and find the nearest gas station or fine dining experience. But when you think about it, in our day to day lives, we don't need directions that much.
GPS and Location Services are huge data and energy hogs. If you have ever seen how much can go on in the background when it comes to Location Services, you would cringe. So, set up your GPS like the screenshot below and you will see a little battery life improvement and data usage go down.
Display Brightness
Settings > Display > Brightness
On my Nitro, the display uses up the most energy by far. So, it only makes sense to lower the brightness a bit to save power.
Developer Options
Settings > Developer Options
The Nitro has a powerful 1.5GHz CPU which uses a ton of energy when in heavy use. Some of you might say, "But Matt, I don't use that many apps that need the CPU." Well, it's not that you use them. It's that the ones you have used are likely still running. For example, even though I always use the 'Exit' menu item in Slacker Radio, it will always show up as a running process in Task Manager.
In the Developer Options, there are a few useful ways to fix this problem.
First, check the box next to 'Don't keep activities'. This will cause whatever app you are using to stop completely as soon as it is not on the screen anymore. This is useful if you have the habit of using the 'Home' button when you are done with apps.
Next, set the 'Background process limit' to something other than the standard limit. I have mine set to 4 processes. This will keep processes that are not tied to any specific app in check.
If you use a lot of apps and games that have to render video, it might be a good idea to check the 'Force GPU rendering' box. This will force apps such as games to use the slightly less powerful GPU in the Nitro for video. Thus letting your CPU relax a bit. I have also noticed that heat doesn't build up as much with this box checked.
Lastly, if you want to know about more of the processes that hang in the background that may cause performance issues, you can check the 'Show all ANRs' box. Personally, I found it annoying.
Power Saver
Settings > Power Saver
I was really excited for this feature but also very skeptical. But, I gave it a try anyway. What this feature does is when your battery level gets to a certain percent that you choose, it will turn off power consuming features and change some settings to use less power. I have mine set to engage at 20% battery life.
The tips I have seen say to check every box. But, because of my profession, I have to have 'Auto-sync' left on for emails and such.
With the settings below, I usually see the last 20% of battery last about 4 to 5 hours of medium use.
CPU Clock
*Requires Root*
Unlike all the tips above, this one will require you to root your Nitro.
As I said before, the 1.5GHz CPU uses a ton of power. When you think about it, unless you are playing games all the time or doing some kind of complex calculation as part of your Quantum Physics experiment on you phone, you really don't need all that power. So, what I did was underclocked the CPU to 1GHZ. This gives me the power I need to do what I do but with more efficient energy consumption.
I used SetCPU for this but there are a few other choices out there that do the job just as good.
As you can see from the screenshot below, I have set the max frequency to 1026MHz and the min frequency to 384MHz (I have since set min to 192MHz). I set the governor to 'conservative' based on this post: LINK. But, I think that any of them will help in different ways.
If you are curious, I'm also inserting a screenshot of my benchmarks after the underclock.
CPU Sleep (Suggested by rani9990)
*Requires Root*
XDA user rani9990 suggested an app called CPU Sleeper that, essentially, puts additional cores into an offline mode while the screen is off.
I can see how this would be advantageous because when your phone is in sleep mode, it really doesn't need all that extra power.
I have had it on my phone since i got up this morning and have noticed a significant jump in battery life already.
Results
Before these tips, I was getting about 8 to 9 hours of medium use on a charge.
After, I get roughly 15 to 20 hours of medium use. (It varies from day to day but hovers between 15 and 20.)
If anybody has any other tips, please let me know so I can add them to the list.

You should also tell people to get CPU sleeper (root) saves tons of battery life for me.
Also, disabling haptic feedback saves battery.
Sent from my GT-I9300

! kick ass post!! well-done. fun read too.
thanks!!1

Sadly, battery life on this phone really sucks even with the optimizations. having compared both, I can say that the Nitro HD with optimizations and 3800 mAh Hyperion battery gets about the same battery life as a Galaxy Nexus on the stock ROM and stock battery.

996gt2 said:
Sadly, battery life on this phone really sucks even with the optimizations. having compared both, I can say that the Nitro HD with optimizations and 3800 mAh Hyperion battery gets about the same battery life as a Galaxy Nexus on the stock ROM and stock battery.
Click to expand...
Click to collapse
Perhaps check your running processes. With these tweaks in place, I unplugged my Nitro at 7:45is this morning and right now, at 2:15pm, I have 79% battery left and I've made two 15 to 20 minute phone calls and rebooted about 6 times because of some testing I've been doing for another thread.
Also, the Nitro does have a faster CPU that would take more power than the Nexus.

I have done all of this, in addition to in Settings/Wireless & networks there's "more..." click that and theres "Mobile networks".. and the option for "Use only 2g networks" I'm using that for only texting while at work and doing pretty decent with battery life. since 5:45 to now 10AM texting all throughout that time I'm at 85% battery.

Kct385 said:
I have done all of this, in addition to in Settings/Wireless & networks there's "more..." click that and theres "Mobile networks".. and the option for "Use only 2g networks" I'm using that for only texting while at work and doing pretty decent with battery life. since 5:45 to now 10AM texting all throughout that time I'm at 85% battery.
Click to expand...
Click to collapse
I actually don't have that option.

mattman86 said:
I actually don't have that option.
Click to expand...
Click to collapse
Uhmm.. maybe its a CM9 only feature.. sorry hijacking then.

i found many of these settings are available in cm9 and after making the changes, it appears to me they work very well. thanks again eh.

UPDATE: I refrained from plugging in my phone all day yesterday and got 14 hours and 32 minutes of medium to heavy use.
Sent/Recieved 191 text messages.
Spent 2 hours and 47 minutes on the phone.
Updated 7 apps from the Play Store.
Played Dead Space for roughly 35 minutes.
Checked Facebook 3 or 4 times.
Read a news article online.
I think the battery did pretty good this time around.

Thanks for helpful tips!
The only problem I got is that the screen turned to back (with music still on) when I started NinjaJump with "Force GPU rendering'" checked.

You don't want force GPU rendering checked...

mattman86 said:
Display Brightness
Settings > Display > Brightness
On my Nitro, the display uses up the most energy by far. So, it only makes sense to lower the brightness a bit to save power
Click to expand...
Click to collapse
What I`ve noticed is that when I set Brightness to 100% I have 3...3,5 hours of wake working screen active time before battery exhausted. It's on ICS leak V18F. But if I set brightness to 30% or "auto" mode I got about 2....2,5max hours of screen active, it exhausts quicker
And secondly, on CM9 it helps me to check off "surface dithering" in 'performance' options. But on official ROMs we haven't this option available to tweak

I found that JuiceDefender has seriously saved me a whole lotta battery. Like seriously. I was getting 12 hours of medium to heavy usage before, and now i can hit 30 hours of medium usage. Then again, Data isn't turned on for me, I use the phone for Wifi and Calling.

rani9990 said:
I found that JuiceDefender has seriously saved me a whole lotta battery. Like seriously. I was getting 12 hours of medium to heavy usage before, and now i can hit 30 hours of medium usage. Then again, Data isn't turned on for me, I use the phone for Wifi and Calling.
Click to expand...
Click to collapse
JuiceDefender saved me tons of battery also. But I noticed that it was always waking my phone up for a second at random times. Have you had that issue at all?

mattman86 said:
JuiceDefender saved me tons of battery also. But I noticed that it was always waking my phone up for a second at random times. Have you had that issue at all?
Click to expand...
Click to collapse
Nope, but I don't look at my phone every waking second. Maybe it did do it. But I'm getting a serious boost in battery life so I don't really care.
Sent from my LG-P930 using xda premium

For me keeping the wifi on (and thus connecting via wifi both at home and in the office) allows me to save battery..
To me it seems strange, because my old phone literally sucked battery while keeping wifi on, but on the nitro wifi consumes less than hsdpa data transfer.

I've added a link to my SetCPU Profiles file in the guide.

low antutu battery benchmark scores
Both stock and CM9 RC2 are disappointing: 250 and 328 respectively. I've applied the suggestions here and don't know if I'm doing something wrong.

I was rather happy with my phone with GB managed by Battery Defender from Infolife. I used to have 1,5 day with "Mostly Idle" usage. Now after upgrade to ICS I just got 10% down per hour on idle. So disappointed. I'll play with your settings a while. May be Battery Defender uninstall/reinstall can help too...

Battery life and 10 tips to extending it

This is actually a copy of a (long) post reply I did in another thread a little while ago but heck, there are lots of posts and questions about battery life and I have 10 tips or things I do that maybe help to some so here it is...
( This was the original question:
What's a good figure for battery life on the GS3? The best I've got is about 31 hours using on demand and bfq. Any one got better life using other settings? I heard someone getting about 43 hours life but that seemed to be a little unbelievable.)
******************
What you reported is definitely "the average". Most actually only get a day, if they're lucky of moderate use and have to plug in before sleep every evening and get going on charge in morning. So its more like 15 hours actually. And your 31 max is a very common high end for people who've stretched it out.
I'm not sure if you're stock rom or not and if rooted either but that makes a big difference.
I'm rooted ( and would ALWAYS RECOMMEND ROOT FOR EVERYONE EVEN IF NOT FLASHING ANY ROMS AND STAYING ON STOCK. The ability to have full control is important.
Changing kernels and more importantly, undervolting, will give you that longer life you're looking for.
I'm currently on KyanROM with either Ktoonez or Faux kernel (heavily tweaking and testing both) and have this phone beautifully undervolted to exceptionally low and very stable mv numbers! Thus getting me that lovely 36-45hour average - on stock battery - (you mentioned you saw posted elsewhere - yes it is possible and many are doing it). I basically only need to plug in every OTHER EVENING or night between 6pm and midnight depending on usage and I'm a moderate to heavy user (with a lovely 3-5 hours of screen time as well) AND I also have my phone overclocked to 1.8Ghz! Surprisingly, the oc doesn't make much battery life impact at all because the phone isn't constantly having to run at high levels, only in short spurts. Actually, due to rooting and kernel change I'm able to have my phone run as low as 192Mhz (actually lower now - 96 - since latest Ktoonez kernel update) during much of its general activity and deep sleep ( which I get a ton of as my phone basically always goes into it when the screen goes off). This saves me A LOT of battery life.
I also use LTE, which is actually one of the biggest if not the largest battery hog, next to screen time of course. But with that being said I only use it when needed and have it turned off when not in use.
As for my peak I was able to squeeeeeze out 87 hours once, on my stock battery BUT that was with some abnormal(for me) measures that really help conservation. Ie, no LTE, under clocked to 1.2Ghz for good part of the three days, much less then normal screen time over the period of which I used it at lowest level with even further reduction via screen filter, I actually used airplane mode during my three overnight sleeps (which I seldom use but if you can hack it, do it! It can really save battery overnight. My current setup basically SIPS MY BATTERY AT 1% EVERY 3.5-4 HOURS OVERNIGHT WHEN IN AIRPLANE MODE), mobile data was off for most of time but did use my wifi at normal level (wifi uses less especially if good signal with few reconnects/scans), used my typical low UV numbers, kept my notification updates/syncs/wakelocks to a minimum and lastly kept my memory virtually clear if unnecessary background apps.
Doing ALL of this allowed me to get OVER THREE DAYS BATTERY LIFE. But keep in mind I seldom do many of these battery saving tips on a regular basis but some do and if you can, they WILL work to extend your life substantially!
I'll give you my general UV mv range numbers and the typical everyday simple battery saving methods I use.
1.My voltage at lowest clock of 192mhz=800mv with gradual (smooth and almost linear curve) increase up to a mere 1200mv at a whopping 1.890Ghz clock.
I use NOOP scheduler with ONDEMAND governor most of the time, sometimes SmartassV2.
My screen off and deep sleep use this lowest 192 clock speed and with no wakeup lag.
(Update - as mentioned, now on latest Ktoonez kernel which has lower min clock and higher max with mote voltage control too so my min is now 96Mhz at 770mv and max of 1998Mhz at 1235mv)
2. I use my screen at 0% brightness most of the time (except when outside or in high lighting environment). I use the brighrness widget app to control this as it is easier and works better then stock settings. I actually even further reduce my brightness with Screen Filter App. That app is awesome and often use it solely for brightness control because it has full control and can dim it to basically full black if wanted. Which is MUCH lower then stock control. Fyi I use my phone a LOT more at night or in dark environments thus allowing me to dim screen HEAVILY yet it still is actually plenty bright with ample contrast in dark environments to do everything. This saves on my battery HUGE!
3. I use LTE when needed and GSM/HSPA+ when not. Seldom turn off mobile data altogether. I do turn off wifi when out and only using mobile data but do remember wifi does use less battery then mobile and both work better and drain less with better signals. If your wifi or mobile signal is low or has to reconnect often that puts heavy strain on the battery.
4. I use Screebl app to have my screen turn off when not in use. Its a great liitle app. Basically let's you turn down screen timeout to 15 seconds or less so screen is never unnecessarily on but it always stays on when in use due to the accelerometer and it knows when the screen is not flat on table! Its very annoying when browsing or doing stuff where screen isn't touched for long periods and the screen goes to sleep! But this stops that! So its always on when upright or in use and when phone down it turns off immediately. But this does save battery by not leaving the screen on unnecessarily when not in use.
5. Very important step and can take some time and research but making sure to keep partial wakelocks and apps keeping device awake to a bare minimum! DEEP SLEEP IS VERY IMPORTANT TO SAVE BATTERY! You basically want it to go into that every time your screen goes off and to stay in it uninterrupted for as long as possible. And many users phones are NOT making it into deep sleep due to partial wakelocks and they don't even know it or how to fix it. Not getting deep sleep can unnecessarily kill your battery!
I use a few tools here: Better Battery Stats/GSAM Battery Monitor/Battery Monitor Widget from within System Tuner Pro (which is my also my main and highly recommended tuner app for CPU oc/uc and UV,etc.).
These apps really help to determine what, if any, apps are causing partial wakelocks ( displaying in wake number amounts and overall wake time) allowing you to determine what to do to fix the problem and let the phone gets as much battery saving deep sleep as possible. One other app that many use and is very popular and effective is Juice Defender. I recently started using it too and its quite powerful and customizable. Definitely another tool in the arsenal.
6.I'm not big on auto app killers and actually recommend against them as Android ICS does this already very effectively but do keep in mind that the more active background memory that is used, the more the battery is drained. So I personally kill unnecessary apps myself from the background whenever possible to save a little battery here and there. Using the apps listed above in #5 can really help to detect a nasty background app or service that is quite possibly unknowingly using a ton of CPU and/or memory, thus draining more battery and also often just slowing down your phone!
7. For those who can use it Airplane Mode is a big saver! Try overnights if wanted as long as missing notifications, emails, calls, updates, etc is alright for you. I seldom use it but it does help.
8. I almost never use my Bluetooth and GPS but when I do that is the ONLY time they are on. They get turned off immediately and really be careful with the GPS in particular because you might be surprised how many things on your phone will use it in the background, sucking your battery! Google Maps and "Network Location Service" can use your GPS or run often in the background waking up your device.
9. Be careful with sound and vibration levels. Haptic feedback too. I don't do much here but its another tip nonetheless.
10. Lastly is treating and charging your battery right! I found an amazing site linked down below in a couple of articles that really explains these batteries and how they work in a very in depth technical level this is still not too hard to follow. Aside from the two links I posted check out the others on the left menu as there is a ton of useful and educational info!
http://batteryuniversity.com/learn/article/how_to_increase_the_runtime_of_your_wireless_device
http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries
Btw I've just received both my 3300mAh and 4400mAh capacity batteries. So I have much testing to do on those too and I plan on reporting back on them as well. Also with screenshots for data and proof...I can and will also post screenshots for all of the numbers and stats I've posted here today with my personal phone/battery accomplishments.
Hope this helps some of you out there because yes this phone can be known for terrible battery life but it CAN be tweaked to SUBSTANTIALLY IMPROVE that life to high standards and keep up with the best of them!
Sent from my SGH-I747M using Tapatalk 2

Here's a little update:
the latest Ktoonez kernel is absolutely amazing on many roms on this phone for both performance and battery life!
Here's some info on my setup and stats:
I can run the 2.1Ghz step but not yet 100% stable so I'm more then fine with 1.998 and every other clock works perfectly! And my battery life is just amazing with the UV I can do.
My levels are as follows:
96 min - 1998 max
780mv min to 1185mv max w/ variances of -55mv to -135mv below stock on all the steps in between. This = incredible! Sweet performance AND battery life =
I've got this thing as low as using only 14mA during deep sleep! I use a 4300 mAh battery now so that's only 1% every 3 hours. So I basically only use 2% when I crash at night and get up the next morning. And I now easily get 2-3 days with fairly heavy use and that includes 7-8+ hours of screen time. Heck, at these low levels I could technically be in standby for almost TWO WEEKS! (Actually 12.5 days or 307 hours). That's amazing!
I'm now getting the performance and life I should be and have always wanted on these things!
Sent from my SGH-I747M using Tapatalk 2

Are you using the ktweeker app? Care to post a screenie of your voltage settings?
Sent from my SAMSUNG-SGH-I747 using xda app-developers app

I just did over in the KyanROM thread... here's the link.
http://forum.xda-developers.com/showthread.php?p=30897840
Sent from my SGH-I747M using Tapatalk 2

Wow I really need to try these tips, I'm nowhere near these numbers. I need to charge in the middle of the day usually. Thanks for the info!
Sent from my SGH-I747 using xda premium

EskimoRuler said:
Wow I really need to try these tips, I'm nowhere near these numbers. I need to charge in the middle of the day usually. Thanks for the info!
Sent from my SGH-I747 using xda premium
Click to expand...
Click to collapse
Well doing some or all of these things should help a fair bit and on your STOCK battery (I assume) you should at least be able to get into the second day on regular basis.
When I used my stock (before getting 4300/4500 mAh batteries) I was finally able to get 35-45 hours out of it and usually only having to plug in to charge on the second late afternoon to evening before bed...
And now with (a good quality) extended battery I can push this thing heavily and get 2-3 days regularly but like stated, gotta have a good rom/kernel/UV/and a few of those battery saving habits.
Sent from my SGH-I747M using Tapatalk 2

Wow!! im going to try this thank you very much for sharing this my battery last 2 days with moderate use i have a extended batterry but i will love to extended more jajaja thanks again
question? what app do you use for undervolt?
Enviado desde mi SAMSUNG-SGH-I747 usando Tapatalk 2

any setcpu profiles? thanks
Enviado desde mi SAMSUNG-SGH-I747 usando Tapatalk 2

Mind sharing your voltages?

meaintsmart said:
Mind sharing your voltages?
Click to expand...
Click to collapse
Already did..in the link up above in the 4th post
Sent from my SGH-I747M using Tapatalk 2

CPU sleeper + juice defender ftw.

thanks will keep this in mind

I followed your UV settings and yes it works great.
One issue I found was that my mp3 ringtones, youtube, and flash video playing in a browser caused some serious audio distortion. Mp3's playing from my music player were fine and videos with my video app were fine too.
I was able to change my mp3 ringtones to ogg files and no more distortion, but youtube is a needed app.
Anyone else notice this issue?
The second I put my UV settings back to stock numbers the audio was fixed.

So after toning the voltage down some I've noticed much better battery life. But I have also noticed a bunch of screen flickering. I'm on task and kt's AOKP JB Rom. I OC to 1.890 and used the voltages that you posted from the kyan thread. I'm going to set voltage to stock and then work down from there to see where I have better performance.
Sent from my SGH-I747 using xda premium

Well if ur getting audio distortion or video issues then certain levels of UV are too low and not stable and must be adjusted.
All the levels I have even at the low levels are completely stable with no issues whatsoever and amazing battery life..this phones hardware is very robust...lucky I guess
Sent from my SGH-I747M using Tapatalk 2

Good post, thanks!

I don't want to be that guy that posts battery charts. Ktoons seems to believe that I have a bad phone since the battery drains quickly like in 3 hours with his kernel uvd. I have tried to battery stats but have not found any irregularity as far as rogue programs. Most of my cpu on regular AOKP is usually at 384 and 1.5
Ktoons says it is not normal. Can you guys affirm this. If so im refurbing on the quick .
{
"lightbox_close": "Close",
"lightbox_next": "Next",
"lightbox_previous": "Previous",
"lightbox_error": "The requested content cannot be loaded. Please try again later.",
"lightbox_start_slideshow": "Start slideshow",
"lightbox_stop_slideshow": "Stop slideshow",
"lightbox_full_screen": "Full screen",
"lightbox_thumbnails": "Thumbnails",
"lightbox_download": "Download",
"lightbox_share": "Share",
"lightbox_zoom": "Zoom",
"lightbox_new_window": "New window",
"lightbox_toggle_sidebar": "Toggle sidebar"
}
Sent from my SGH-I747 using xda premium

Followed a lot of these tweaks and everything seems to be helping! With some light to moderate use on a qcell 4500mah battery I'm only down to 75%.
Sent from my Nexus 7

I thought fauxs kernel u can't adjust the voltages? My phone hates ktoonz kernel. If I lower it anymore then 384 I get bad audio distortion. Now with faux my phone is fine but I want to be able to undervolt it. Is there a way to do that?
Sent from my Galaxy Nexus using xda app-developers app

Any idea why my phone doesn't want to keep the overclocked/undervolted CPU settings ? It's not rebooting or anything, but after awhile I'll go into a CPU tweaking app (KTweaker or System Tuner) and everything will be back to stock settings.
I'm on AOKP with Ktoonsez kernel.

How to undervolt and get better battery life. Please post your results and how to.

Hey all, this is a thread I saw on different forum and think it is would be good for noobs like myself to benefit from. How to undervolt your CPU and also post your Galaxy Note 2 specific results. I have tried these next steps, and so far I'm doing okay (can't give an accurate results on battery life yet). Like I said (I'm not ashamed to say I'm a noob) but if others can throw their two cents in, we can all learn and this thread can be useful. The next part was cut and paste d from other forum. And I deleted the url for the kernel and root
Prerequisites:
1. Must be rooted and recommended kernel
2. Download and install System Tuner
3. Download and install Stability Test
Steps:
1. Open System Tuner and select CPU
{
"lightbox_close": "Close",
"lightbox_next": "Next",
"lightbox_previous": "Previous",
"lightbox_error": "The requested content cannot be loaded. Please try again later.",
"lightbox_start_slideshow": "Start slideshow",
"lightbox_stop_slideshow": "Stop slideshow",
"lightbox_full_screen": "Full screen",
"lightbox_thumbnails": "Thumbnails",
"lightbox_download": "Download",
"lightbox_share": "Share",
"lightbox_zoom": "Zoom",
"lightbox_new_window": "New window",
"lightbox_toggle_sidebar": "Toggle sidebar"
}
2. Drag the slider shown in the picture to overclock or underclock CPU. In this picture we are overclocking to 1.8ghz
3. Select Voltage at the top to get to CPU voltage settings.
4. Ok, here select the buttons as they are in the picture.
a. Select the Green circled button to save current stock default settings.
b. Select the Yellow circled button 4 times exactly to reduce the millivolts by 100.
Stability Testing:
Now we really should make sure that it can handle it under load right? :silly:
1. Open Stability Test and select CPU+GPU Stability Test.
2. Select Full Details - Proceed.
3. The app will now start stressing your cores. I waited until at least 10 cpu passes before quiting the app...
Cliffnotes:
-By default, your settings will revert back after you restart your phone. You can set them to load at boot, but don't do this unless your absolutely sure that they're stable!
Open System Tuner - CPU - Menu key - Settings - Active Tweaks - Reapply CPU Settings - On Boot Completed
-Whenever i tried to lower the mv more than 100 below stock at 1.8ghz, my phone rebooted
-I am in no way responsible for anything that might happen after performing the above, even if you start your sentence with the word "but"
-here's stock settings in case you need to revert
[/QUOTE]

This is an interesting project but I would think that the average user would not need this as battery life is pretty good. Speaking for myself, I am able to get through the whole day without any issues.
Of course there might be other reasons why someone would want to do this.
Doc

Thanks
Sent from my SGH-I777 using xda premium

DocEsq said:
This is an interesting project but I would think that the average user would not need this as battery life is pretty good. Speaking for myself, I am able to get through the whole day without any issues.
Of course there might be other reasons why someone would want to do this.
Doc
Click to expand...
Click to collapse
from what i've read, undervolting save very little battery time as the processors are pretty efficient anyways. i don't have actual numbers, but i'd guess you'd get a few extra minutes - which some may really need.
it's that freaking gargantuan screen that sucks the most juice. there used to be a mod to undervolt displays. they had it working on an OG galaxy tab. i never really seen it used anywhere else.

I have an international version of galaxy note 2. I'm currently using AllianceROM and Perseus kernel. And my stock voltage is way way higher than yours. Like 1400mV mine, 913mV yours. Can I undervolt my note 2 to same specifications like yours? Thanks.

This is interesting but setcpu when I had it on my last phone worked awesome and was very easy to use.
Sent from my Amazing Galaxy Note 2!

rjisanandres said:
I have an international version of galaxy note 2. I'm currently using AllianceROM and Perseus kernel. And my stock voltage is way way higher than yours. Like 1400mV mine, 913mV yours. Can I undervolt my note 2 to same specifications like yours? Thanks.
Click to expand...
Click to collapse
You is 1400 mV on 200 MHz? It's probabky 1400 on 1.6 ghz.
Sent from my SCH-I535 using xda premium

I also have Perseus kernel overclocked but still have great battery life. Thanks for the tip though might try it and compare the difference just in case.

I agree with DocEsq.. It is interesting indeed, but is it really necessary?
Can you overclock it?

My note 2 seems to be charging forever after undervolting. I'm talking for about 6-7hrs charging time here. What seems to be the problem? I'm using Perseus kernel. TIA!
Sent from my GT-N7100 using Tapatalk 2

I once conducted a test with my evo3d. I basically ran an amp meter inline with the battery. Measuring the exact power consumption. I dont remember the exact specs, but undervolting and underclocking my phone compared to stock made a very minute difference in actual power consumption. A difference of about 8-15ma. This was during a CPU full load scenario for about 10 seconds. Even loading the CPU with the screen off to take as many variables out as possible it was very little difference. During normal operarion the power consumed was virtually identical.
So the 2 to 3% of the day (overall time) your phone is actually under HEAVY load, it won't make much difference. It did make a performance impact. So not much benefit, just reduced performance.
Now overclocking and/or overvolting did make a larger difference in consumption at high constant load.
Want to ACTUALLY make a large impact on your battery life? Make sure you don't have any apps preventing your phone from sleeping and run the absolute lowest screen brightness you can stand.
YMMV.
Sent from my Galaxy Note 2 using Tapatalk 2

The benefit I found from undervolting isn't better battery life, it's reduced heat which in heavy use provides better performance due to no cpu throttling. I'm running 1800mhz using less battery than 1600mhz and with same temps as stock. Very stable, been running this for a month now at least.

Action B said:
The benefit I found from undervolting isn't better battery life, it's reduced heat which in heavy use provides better performance due to no cpu throttling. I'm running 1800mhz using less battery than 1600mhz and with same temps as stock. Very stable, been running this for a month now at least.
Click to expand...
Click to collapse
What app did you use to undervolt?
Sent from my Amazing Galaxy Note 2!

yankees45us said:
What app did you use to undervolt?
Sent from my Amazing Galaxy Note 2!
Click to expand...
Click to collapse
I'm using the stweaks app that comes with perseus kernel.. I've undervolted quite a bit and I get better battery life.. Still not quite as good as I had stock, but definitely a lot better for being over clocked.. I just reduce each level to the level below it and run for a few to check stability and keep going from there.. So far I have had no trouble at all with undervolting.. Certainly nothing like I did with my elte.. Here's where I've been for almost a week as well as today's battery results so far with Pandora playing over 3 hours straight and moderate use..
Sent from my SPH-L900 using Tapatalk 2

Yeah, just to let you know that there certainly isn't a linear correlation between undervolting and underclocking and power usage. That might have been the case in simpler times, but with modern multi-core microprocessors, you might actually be decreasing battery life by screwing with your clock rate or voltage. Yes, the defaults err on the side of caution, but it's a whole lot of work for little to no gain.
For example, by reducing your phone's clock rate, you might actually be forcing your phone to be spending more time at load; thereby not allowing it to fallback to its sleep state. There is also something called the power wall, where an increase in operating frequency requires an exponential increase in power. However, the reverse is also true. It can be counter-intuitive to think of it this way, so a practical example is how on a 100 mile trip, a 25 mpg sedan saves 4 gallons of gasoline over a 12.5 mpg SUV. However, over the same distance a 50 mpg hybrid saves only 2 gallons over the 25 mpg car. By that same logic, a mythical 100 mpg vehicle would only save 1 gallon of fuel. It's the law of diminishing returns. Then of course, there are the stability issues that you should take into account.
There is a lot that happens behind the scenes regarding power management. Your phone is capable of intelligently scaling it's processors, voltages, and frequencies up or down all based on current and expected demand. There are people who spend a lot more time doing this for a living, and the idea that you can do it better is probably a falsehood. If you want MOAR POWER, by all means overclock/overvolt it (just don't fry it), but trying to get an extra couple minutes of run time is likely a waste of some hard work. It's the software that kills your battery, not the hardware.
Talking about computer architecture can be complicated and boring, but start with searches on "rise time" and "logic level transitions" if you want to want more background.

Action B said:
The benefit I found from undervolting isn't better battery life, it's reduced heat which in heavy use provides better performance due to no cpu throttling. I'm running 1800mhz using less battery than 1600mhz and with same temps as stock. Very stable, been running this for a month now at least.
Click to expand...
Click to collapse
Interesting... whenever I'm dling using a torrent client my phone gets a nasty fever and I've gotta set it down somewhere as it will literally make me sweat, lol. I do b there think I'll be undervolting just for that specific circumstance but that is a very interesting concept...
anishannayya said:
Yeah, just to let you know that there certainly isn't a linear correlation between undervolting and underclocking and power usage. That might have been the case in simpler times, but with modern multi-core microprocessors, you might actually be decreasing battery life by screwing with your clock rate or voltage. Yes, the defaults err on the side of caution, but it's a whole lot of work for little to no gain.
For example, by reducing your phone's clock rate, you might actually be forcing your phone to be spending more time at load; thereby not allowing it to fallback to its sleep state. There is also something called the power wall, where an increase in operating frequency requires an exponential increase in power. However, the reverse is also true. It can be counter-intuitive to think of it this way, so a practical example is how on a 100 mile trip, a 25 mpg sedan saves 4 gallons of gasoline over a 12.5 mpg SUV. However, over the same distance a 50 mpg hybrid saves only 2 gallons over the 25 mpg car. By that same logic, a mythical 100 mpg vehicle would only save 1 gallon of fuel. It's the law of diminishing returns. Then of course, there are the stability issues that you should take into account.
There is a lot that happens behind the scenes regarding power management. Your phone is capable of intelligently scaling it's processors, voltages, and frequencies up or down all based on current and expected demand. There are people who spend a lot more time doing this for a living, and the idea that you can do it better is probably a falsehood. If you want MOAR POWER, by all means overclock/overvolt it (just don't fry it), but trying to get an extra couple minutes of run time is likely a waste of some hard work. It's the software that kills your battery, not the hardware.
Talking about computer architecture can be complicated and boring, but start with searches on "rise time" and "logic level transitions" if you want to want more background.
Click to expand...
Click to collapse
Like the way you put that. Good analogies there it just seems like the other day that undervolting was the hip thing to do. Technology just moves at such a wonderful pace though. Just one little FYI though, since i do like you analogy i would like to point out that the law of diminishing returns actually refers to something else entirely. I know, I know, nitpicking, but it's just that everyone is always off the mark with that one and, well I guess I'm just an anal ahole (and an economics major, ,which I guess just overall makes me an a hole, ,lol)

If you have ever pulled apart a laptop and saw how much thermal paste the engineers at the factory "designed" for their to be on there, or seen the air/fuel ratio most cars roll off the lot with, or ever replaced an intake in a vehicle with a high performance unit I'm not sure you would feel the same way about you yourself not being to do a better job.
I get the point, and I believe often there is validity to that point, but sometime things just aren't that simple. This is where power gains come from in tuning a car (which i do). This is where efficiency is raised by removing restrictive components in a vehicle (intake, exhaust, etc) and where cooling performance is increased on a CPU with the proper application of a quality thermal paste.
Whenever time is money, and you are deciding between your bottom line and something that works and something that works as well as it can, shortcuts are made and corners are cut. Perhaps they could have spent another 200 hours for the team to absolutely optimize the processor for each device, but the cost would have been an additional $20,000 dollars. This is not always the case, but with processors I think it is. I will undervolt everytime and I do take objective measures for battery and I agree gains are relatively small. For cooling, I found the difference to be very significant at 1800, mhzI didn't check at 1600mhz, however. I can run a full Antutu benchmark as much as I want at room temperature and never exceed the throttling point (70 C if i remember correctly). Now, I am in no way saying these are facts, these are opinions, so I could be wrong of course.
Psychotic-Cerebellum said:
Interesting... whenever I'm dling using a torrent client my phone gets a nasty fever and I've gotta set it down somewhere as it will literally make me sweat, lol. I do b there think I'll be undervolting just for that specific circumstance but that is a very interesting concept...
Like the way you put that. Good analogies there it just seems like the other day that undervolting was the hip thing to do. Technology just moves at such a wonderful pace though. Just one little FYI though, since i do like you analogy i would like to point out that the law of diminishing returns actually refers to something else entirely. I know, I know, nitpicking, but it's just that everyone is always off the mark with that one and, well I guess I'm just an anal ahole (and an economics major, ,which I guess just overall makes me an a hole, ,lol)
Click to expand...
Click to collapse

The TIM wasn't put on there by the engineers who designed the chips; they are put there by workers being paid next to nothing.
Your phone doesn't have a CPU, it doesn't even use thermal paste; it's usually just a rubber contact patch and passive heat dissipation. This actually brings another point where overclocking can sometimes reduce performance due to throttling by thermal constraints (why our phone has such a low GPU rate than what it is capable of in other phones with better thermal envelopes).
You aren't replacing the SoC, you are changing the software that determines how to set the voltage/clock multiplier. The car analogy isn't valid.
And I stand corrected regarding the Law of Diminishing Returns; never paid attention in macro-econ. I think was because my prof. was more interested in forcing his political ideology upon us than actually teaching the subject. :silly:
EDIT: Keep in mind, the engineers rarely get what they want. The product the consumer ends up getting is usually dictated through a collaboration of what the business and marketing teams want. The engineer might request a large cooler clamp with a perfectly lapped surface and a carbon-based TIM. In reality, the consumer gets a dinky fan with melt-on TIM and retention springs. Money talks.

anishannayya said:
The TIM wasn't put on there by the engineers who designed the chips; they are put there by workers being paid next to nothing.
Your phone doesn't have a CPU, it doesn't even use thermal paste; it's usually just a rubber contact patch and passive heat dissipation. This actually brings another point where overclocking can sometimes reduce performance due to throttling by thermal constraints (why our phone has such a low GPU rate than what it is capable of in other phones with better thermal envelopes).
You aren't replacing the SoC, you are changing the software that determines how to set the voltage/clock multiplier. The car analogy isn't valid.
And I stand corrected regarding the Law of Diminishing Returns; never paid attention in macro-econ. I think was because my prof. was more interested in forcing his political ideology upon us than actually teaching the subject. :silly:
EDIT: Keep in mind, the engineers rarely get what they want. The product the consumer ends up getting is usually dictated through a collaboration of what the business and marketing teams want. The engineer might request a large cooler clamp with a perfectly lapped surface and a carbon-based TIM. In reality, the consumer gets a dinky fan with melt-on TIM and retention springs. Money talks.
Click to expand...
Click to collapse
1. The voltages are set by an engineer, that is what I was referring to.
2. The CPU thing was an analogy as was the car. Not a direct comparison. The analogy is referring to how there is set fuel and timing tables just like there is set voltage tables, both might not be the most efficient from the factory, tweaking them can improve things. How is this completely not valid?

[Q] UV, UC, other Kernel options.

Android 4.2.1
CyanogenMod 10.1 Snapshot M1 (21/1/13)
Franco Kernel R364
I'm trying to maximize my battery time.
(Power mode BeastlyBattery 192MHz~1036MHz, Governor: Lazy, IO Scheduler: deadline, Screen of Max Frew: 384MHz)
I want to UV my CPU (and maybe IVA and GPU also, does it helps too?) to save some battery.
Should I just decrease the voltage a bit, use stability test app and keep going till there will be errors,
or I can just decrease like someone else on the web and then keep going..?
Can it do something to the device? (because Its just undervoltage..)
For how long I need to run the stability test?
I saw this topic:
http://forum.xda-developers.com/showthread.php?t=1599025
and he says:
"1. It has been tested that the 700Mhz frequency is prefereable over the 300Mhz one, due to the drops on frequency signal of the phone."
Anyone tested this?
Does UV degrades preformance?
What is SmartFlex?
Anything else I need to know about that?

Im gonna make this one quick, so my apologies if I don't address your questions directly.
Prior to my Galaxy Nexus, I had a T-Mobile SGSII. I too had the belief that undervolting/clocking would improve my battery life substantially. It seemed to work but then I was only getting the results that I wanted to get, and thats because I went to extremes to lowering my screen brightness to minimum and using my phone a fraction of what I used to.
With the help of others and trial and error, my major conclusion is that undervolting/clocking, though normal headset use will not improve your battery life by a landslide. Android is so well optimized to save you as much battery as it can. Sure there are things here in there that interrupt that optimization such as bugs or kernel issues but that something even undervolting/clocking will not be able to solve.
If you do go into undervolting/clocking your device, please keep in mind that the most you will probably get out of it is maybe 45 minutes to 1hr extension, but thats not display time.
What you can do to improve your battery life is turn off whatever sync services you don't use, lower your screen brightness ( the display is the major battery hog in the GN and SAMOLED devices), use dark wallpapers and dark themes if apps support it, use wifi, disable 3G when not in use. The radio you use can also potentially affect your battery life and signal quality.
Those are just a few suggestions, the rest is up to you.
Good luck!
P.S. Kernels also add variation to the longevity of your battery life. It's been a very long time since I touched CM10 so I'm not gonna go and defame that ROM but do try something else that possibly offers better battery life. If MODs are a MUST for you, then you will be faced with a lower battery life compared to stock based ROM's. It won't be an extreme difference but the difference will be there. If I may suggest a ROM, try this one. I can honestly say I can get up to 3-4 hours of display time on it with about a 12 hour standby.

I read a lot on the web that it does help to battery time.. :S

anyone?

You're not going to see much difference. Running the cpu at a lower clock speed just means it will take longer to complete the same operation so you'll use just as much battery.

063_XOBX said:
You're not going to see much difference. Running the cpu at a lower clock speed just means it will take longer to complete the same operation so you'll use just as much battery.
Click to expand...
Click to collapse
And undervoltage?
Different overnor?

Undervolting will have minimal effect during actual use and a governor is based on specific user needs. One might save me battery while another works better for your usage. You need to actually mess with setting instead of just asking others what they use.

[Q] excessive battery consumption

Hello guys,
a few days ago I bought the notes 8.0 wifi and after a few hours they already had administrator permissions.
I left the tablet that becomes exhausted and completely after a night in office, in the morning I started to make some changes: new rom and kernel immediately immediately!
I state that in Italy are the CEO of an interesting blog where we treat only Google Experience products novel that I'm not really, but ...
Turning now from the Nexus 7 (I still have it) the difference for the better I feel about this tablet but I have noticed, however, an excessive drain on the battery, then not doing anything so important: the hours of active screen only 3/4 albeit with wifi always on!
I tried to set all the Governor also present with heavy undervolt but I have not noticed noteworthy improvements ...
nb. Rom and kernel belong to @civato
Tell me your experience, thanks guys

I didn't understand all of your post, but wanted to share my experience:
Leaving the screen brightness on auto is essential to get reasonable battery life. On full brightness my tablet battery runs out way too fast. I do think this device has the shortest battery life of 7 other tablet/phone devices I have previously used for multiple full days (I cannot judge with less usage). But as long as you leave it on auto brightness most of the time, it has managed to get me through each business day since it was released.
Sent from my GT-N5110 using xda app-developers app

reply
thanks for your expertise ...
you are absolutely right but also the tablet in standby consumes a small percentage of the battery, that's not good, at least to me.
I'll talk with the developers for the right settings in the kernel ... hopefully

I found that I only use a few percent when its in stand by. Heres what I have my settings as and why
Brightness - either auto +5 or 50% switching between the 2 as required.
Sync off.
Power saving mode - on unless I want to play resource heavy games.
GPS off. only turn it on if an app specifically requires it (navfree)
Bluetooth off.
spen battery saving mode on. the spen layer uses charge so no point having it on unless i need it. if im using my 8pi pen i just leave the spen out a little, using it like a switch.
Other battery saving things.
Auto airplane mode - app that turns all the signals off when the screen is off.
trickster mod - under volted by 75 on the CPU accross the board (had a few crashes on 100). also undervolted the GPU and changed the ramping threasholds.
- govner set to lulzactiveq which is a modified interactive but also with the benefit of limiting the cpu when the screen is off.
- set ignore_nice_load to 1. so that nice to have processes are now no longer run. only the higher priority ones are.
greenify - set various apps to hibernate stopping them from taking the tablet out of sleep.
Think thats everything.

The primary settings you listed @hertsjoatmon, are standard on Android (and better on Samsung devices) say: I will use them for years.
The second part is more interesting, in fact undervolt to -75 they had not yet tested on this note 8 but if you tell me that the tension holds well-being.
Also on the GPU did you apply the undervolt?? mmmm
The Governor me most is satisfying, at least in terms of battery life - albeit with some lag micro - is "ondemand" (100 -> 1200) with frequency freeze (of 4 cores), thanks to kernel @civato :good:
Standby does not consume almost nothing but if you use the goodness of the screen, wifi and all notifications accesse lead to excessive battery consumption that even my Nexus 4 behaves this way (having then 2100m)

Piè_Nexus said:
The primary settings you listed @hertsjoatmon, are standard on Android (and better on Samsung devices) say: I will use them for years.
The second part is more interesting, in fact undervolt to -75 they had not yet tested on this note 8 but if you tell me that the tension holds well-being.
Also on the GPU did you apply the undervolt?? mmmm
The Governor me most is satisfying, at least in terms of battery life - albeit with some lag micro - is "ondemand" (100 -> 1200) with frequency freeze (of 4 cores), thanks to kernel @civato :good:
Standby does not consume almost nothing but if you use the goodness of the screen, wifi and all notifications accesse lead to excessive battery consumption that even my Nexus 4 behaves this way (having then 2100m)
Click to expand...
Click to collapse
my clock and voltage settings are discussed here... http://forum.xda-developers.com/showthread.php?t=2319953
I've not really updated any of my threads since coming back from holiday. I will do at some point but im pretty happy with my set up at the moment and have only been lurking on here rather than actively contributing these last few weeks.

the situation seems to have improved a bit, with cuts of volts everywhere: P
let's see if over time more kernels will do miracles ...