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My HD2 is running at around 20% CPU usage when idle according to BATTClock. This is even after a hard reset with just Batclock installed, no radios on, and HTC Sense shutdown (just on old Windows today screen). Is this normal? No wonder the battery life is so short.
My Touch Pro generally shows 1-2% CPU usage when idle even with phone and push email on.
Task manager doesn't show any processes or application using that amount of CPU. Is it just Battclock that is wrong or is something else going on? I have turned off all location services.
Nick
Interesting fact. Needs more research though...
I've tried everything I can think of, including switching off automatic backlight sensing, location settings, etc. and Battclock still shows around 20% with nothing running. Any ideas for a more sophisticated tool to monitor the CPU? Does anyone else with Battclock installed notice this?
And if battclokck use 20% of cpu ?
dorigny said:
And if battclokck use 20% of cpu ?
Click to expand...
Click to collapse
BattClock itself does use almost no CPU. But HD2 has the ability to lower the CPU speed. I use a Microsoft API to get the idle percentage. Apparently this Microsoft API does not correct for the CPU frequence change?
You can check with a Task Manager, which process consume how much CPU, like FdcSoft TaskMgr. Then you can also check if BattClock is wrong.
I am planning to add another method for measuring the CPU spent, so for now you can better first check if BattClock is right or not. I have a Touch Diamond and there the CPU percentage is reported the same as the Task Manager.
WEll, mine is 56% atm and i have no idea why.
the only reason i can think of is g-alarm and messenger live
On a device that changes the CPU clock to meet demands, CPU percentage means nothing if you don't have a way to know at the same time what the current clock is.
And yes, Battclock itself might not use a lot of CPU, but it seems its way to draw itself on top of the menu bar is not very efficient. A bit flaky, the redraws are not clean, and I wouldn't be surprised if the system calls it uses do use a lot of CPU.
kilrah said:
On a device that changes the CPU clock to meet demands, CPU percentage means nothing if you don't have a way to know at the same time what the current clock is.
And yes, Battclock itself might not use a lot of CPU, but it seems its way to draw itself on top of the menu bar is not very efficient. A bit flaky, the redraws are not clean, and I wouldn't be surprised if the system calls it uses do use a lot of CPU.
Click to expand...
Click to collapse
Mmmm....I wonder what you're basing your comments on. Are you saying that ZuinigeRijder is lying?
kenkiller said:
Mmmm....I wonder what you're basing your comments on. Are you saying that ZuinigeRijder is lying?
Click to expand...
Click to collapse
The Qualcomm CPU, the one the HD2 has, reduces it's clock speed when it is not needed to run at full capacity to save battery life.
i.e. If the CPU is running at 1Ghz, and a program is using 1%, it will drop the clock speed (due to lack of activity). Say it then drops to 100Mhz, it will then be running at 10% of the CPU clock speed.
A simple way to check wether battclock influences the readings somehow (which I don't really believe) would be to turn it off and check, as zuinigerijder said, with fdcsoft advanced taskmanager.
BTW I also get ~20% usage when idle, in some manila interfaces I get to lowest values of 7%, but then back to ~15% and then again ~20%
No way to know the current clock of the cpu?
rp-x1 said:
The Qualcomm CPU, the one the HD2 has, reduces it's clock speed when it is not needed to run at full capacity to save battery life.
i.e. If the CPU is running at 1Ghz, and a program is using 1%, it will drop the clock speed (due to lack of activity). Say it then drops to 100Mhz, it will then be running at 10% of the CPU clock speed.
Click to expand...
Click to collapse
I think you've hit the nail on the head. When I start a new program the CPU% drops briefly to 1-2% before climbing again. I guess this is the device ramping the processor back up before launching the program, hence dropping idle usage from 10-20% of say 100Mhzto 1-2% of 1000MHz.
Cheers
Nick
Extract ,power settings, from omnia 2,is it possible?Put it on htc hd2,in cab format,regulate the speed on the CPU and save the battery life?Anyone?
Be warned that this thread is now outdated. There might be more current guides available…
THE ULTIMATE GUIDE TO MAKING YOUR BATTERY LAST LONGER ON YOUR HTC HD2 WITH ANDROID
OK I suppose this should be stickied as I've found numerous threads saying various stuff, but not a single thread, dedicated solely to this, providing useful and organized info.
Note: This guide is by no means definitive. Please feel free to correct me and add more tips, I'll be sure to add them to this post.
STEPS:
1. Try out a few ROMs and Radios to see which combination works best for keeping Android run as long as possible.
I have yet to find the best combo for my phone, but generally, the lightest ROMs with not much bloat in them (lots of items removed, fast startup) work best. With Radios it's all trial and error – a Radio that works miracles for one user is useless for another. You just have to try and see.
I know this is probably driving you crazy as you can read it everywhere around, but this can't be stressed enough: Don't flash your phone with a ROM/Radio you're not absolutely sure won't brick it. No one wants you to brick your expensive device. Read the flashing guides very carefully before you go on and do it.
Updating your build's Kernel is also a good idea.
2. Make sure you boot Android up as fast after running Windows as possible.
This one is crucial as it seems to affect your battery a lot.
To aid this, you can:
Download and install this (free) app (Exceller Multiple Build Loader is what I use, but you can choose something else) for the WM6. It enables you to autoboot into Android in the timespan of three seconds after running Windows, which is what you ideally want to do.
Disable HTC Sense in WM, it's unnecessary if you just want to boot into Android and takes a lot of time to load up. To do this, go to System settings, press Home, go to the Items tab and uncheck HTC Sense. You may want to check Windows Default to have at least the Zune-style interface to start from, but this isn't necessary if you're ok with an empty homescreen in WM.
3. Decrease the system load by automatically killing apps you no longer use.
This one gives a fair battery boost. By default, Android keeps all apps ready in RAM even if you press Home or Back to exit them to make them start quickly next time you need them and to keep their state. Most apps have a suspend mode which enables them to demand close to zero system resources as they run in the background, but some don't and close to zero isn't zero.
Download and install Automatic Task Killer (free) from the Market.
It gives you a list of the installed apps and enables you to uncheck those you don't want to autokill. It can also add your new apps to the list automatically.
Don't forget to uncheck applications you need to be running constantly, such as SetCPU (see below).
According to hastarin, this doesn't give you a battery boost. See the "What DOESN'T improve battery life" section. You can use AutoKiller Memory Optimizer, if you want to tweak your RAM – this app lets you set the limits for automatically killing apps only when you're low on RAM, which in turn may give you a battery boost.
4. Decrease the CPU performance when it doesn't need to perform at full speed.
I'm sure you're proud of your HD2's Snapdragon running at 1 GHz, I know I am, but it also drains a lot of battery when running on full speed.
NOTE: Using SetCPU with hastarin's R8 Kernel makes it redundant as the Kernel already has an interactive CPU governor in it. Thanks to socrated13 and atticus182 for this tip.
Download and install SetCPU ($1.99) from the Market.
It allows you to underclock your CPU to save battery. You can set profiles and play around with them. Generally, you don't want to set the minimum frequency too low as some tasks may then consume significantly more time to complete, wasting the energy you gained.
If you just want to try the app first to see if it helps, you can get it for free (search for SetCPU here at xda) and donate later by buying it on the Market (and please do, the developer put a lot of effort into it).
5. [INFORMATIVE] See how much energy your phone drains.
This one is not compulsory, but helps to get a general idea of how much energy your phone drains when you do such and such.
Download and install the Current Widget (free) from this forum. Just do a search on "current widget" and it should be the first post that comes up (don't worry, yes it's under Samsung Vibrant, but it works just as good for the HD2)
It allows you to put a widget on one of your home screens, where you can see the current your phone is currently draining. Can be set to update at various intervals. I prefer 30 s as it gives me enough time to shut down an app and look at it to see how much current the app itself is draining.
6. Decrease the brightness of your display.
This saves an incredible amount of battery life. I know you love your AutoBrightness, but it sets the brightness unnecessarily high, so until someone makes an AutoBrightness app with customizable overall brightness (once I get into programming apps for the Droid a bit, I might do it), you're left with doing this yourself.
Download and install the Brightness Rocker Lite (free) app from the market.
It displays a brightness bar everytime you bring up the volume control and thus lets you quickly change the brightness. Use the minimum brightness to see everything clearly and you should conserve a lot of juice.
7. Only use wireless functions when needed.
Having the mobile data connection, wifi, GPS or bluetooth enabled all the time causes severe battery drain. Sometimes even after you disconnect, the data connection connects again without you even knowing, downloading Over-the-Air updates or Weather, draining your battery unnecessarily.
Have a quick way to monitor which services are on and to turn them off (preferrably, have a widget/widgets on your home screen - I recommend the native Android widgets).
8. Recondition your phone for your battery after flashing each new Android build. (Thanks to t1h5ta3 for this tip)
Flashing a new Android build erases the battery stats and automatically rebuilds them based on voltages it sees, i.e. you need to recondition after each flash to get max battery life. The values are stored in the following file: data/system/batterystats.bin – if you delete this file, you set the new ground for making a new one from the value you want.
You can use the "battery life" widget by curvefish to show you temperature, voltage etc. What you're going for is voltage larger than 4.2 V on full charge.
To recondition:
Turn off the phone, plug it in, preferably overnight.
Boot the phone up while still pluged in.
Delete the batterystats.bin file ether through adb or terminal.
Drain the battery fully, until it powers down. Wait a minute or two and reboot it to drain it completely.
Congrats... your phone now knows corect voltage values for 100% and dead.
To delete the batterystats.bin file:
Find the means to be able to punch in lines of code. You can do this either by downloading and setting up the Android SDK or using a simplifying app like Droid Explorer. Do a google search for whichever you prefer.
Punch in the following code:
Code:
rm data/system/batterystats.bin
Or just find the file in Droid Explorer and delete it.
What DOESN'T improve battery life:
Getting a slower (and thus presumably less power-consuming) SD Card – because a slower SD card actually makes things worse as it needs more time to perform a task and thus keep the CPU busy a longer time.
Underclocking your CPU too much – similar reasons
Killing tasks automatically immediately after closing them – this apparently makes battery life worse, because when a program is in RAM, it doesn't consume system resources, but when you run it again, it does. Thanks to hastarin for the clarification.
Useful threads concerning battery life:
[REF] UPDATE: ALL GOVERNORS! Save battery while running ANY Android build (featured by the xda crew)
battery voltage / wipe batt stats
Battery Solution the **FINAL POST**
Time to Recharge to Full Battery
[TIPS] Thoughts on improving battery life for Android on the HD2
[UPD] 48hours + battery with mDeejay Froyo Z v1.7
Best SD Card for Overall Android Battery Life
Increase Battery Life [WinMo registry tweaks - Need confirmation] (do give this a try)
Hope this helps. If you have more tips or on-topic threads, I'll be delighted to add.
also see http://forum.xda-developers.com/showthread.php?t=827355
a properly conditioned battery does wonders for battery life. a fully charged battery shuld be over 4.2v . i was finding that depending on the the true state of charge when flashing, that is the level that was being assumed by the phone as " 100%" charged. ie: when i flashed my current rom it quit charging @ only 3.7xx volts... far from fully charged.
see my thread on the file to delete etc.
edit: after doing alot more research; heres what ive found...
for what its worth: Li-Io battery technology realy isnt different whether it be a phone, rc car, etc...
our batterys are a single cell. ie: rated 3.7v
4.2-4.25v is concidered by the industry as fully charged
3.7v is nominal voltage
3.2v "shorted" voltage : ie: voltage sag due to max discharge @nominal voltage
3.0v discharged
2.5v protection circuitry kicks in.
this jives with what i am now seeing on my phone after wipeing stats and calibrating...
it is also a industry standard to fully discharge ( 3.0v )about every 30 discharge cycles.
edit
Thanks, I added your tip in the first post (will add the link to your thread too, forgot to do it now and can't edit within 5 minutes of last edit yet)
no problem.
im new to playing with the hd2, but been playing with android for well, just about 2 years (early G1 adopter)
it shocked me coming to this forum and seeing the same question worded diferently atleast 7 times on the first page.
lets hope mod's will sticky this..
I'm no expert but from what I've been seeing the difference setCPU makes with the new hastarin kernel's is negligible. In fact I don't think you can use setCPU with with r8 anymore...
Excellent thread! All info was scattered throughout the forums, and this is a nice thread to sum up everything!
Indeed, using hastarin's R8 you won't need to use setCPU since hastarin has included an interactive governor in his kernel
R8 is a vast improvement over the older kernels, I would reccommend it to everybody that uses Android on his/her HD2!
Slampisko,
Very nicely done and there should be more informative guides like this!
Should be made an instant sticky.
PLEASE do yourself a favor and don't use an automatic task killer. Just because an app is in memory doesn't mean it's using CPU and therefore battery but it will use it to run it again after you killed it.
If you must tweak things here use Autokiller Memory Optimizer to change the levels the out of memory optimizer kicks in at.
Of course if you have an app that refuses to close or is just chewing cpu for no reason then manually killing it is fine.
More info linked in my FAQ in my sig.
Sent from my HTC HD2
Thanks for all the feedback! I'll edit the first post to include the additional info...
Hey guys, cool guide
I tried somes tuff, and read various posts, but somehow I cant figure out why my HD2 with MDJ FroYo Sense Clean v. 2.2 [kernel: hastarin R8] keeps sucking the battery empty so far.
Only program i installed in addition to the Android version mentioned above, is the Current Widget to the how much mA it drains.
Those are my settings:
MDJ FroYo Sense Clean v. 2.2 [kernel: hastarin R8]
GSM only (2G)
Data disabled
Wifi disabled
GPS disabled
Bluetooth disabled
syncing disabled (Background data + auto sync both disabled)
I also killed all running things that i think i dont need and still Current Widget shows me, battery drains in standby 55mA-60mA
So i was wondering what i am missing??? since most of the users get a standby mA of 8 or below... I tried for several days now, but somehow i cant find a solution...
just an update from me....
after conditioning the battery, im currently @27 hours since unplugging, gps, and wifi turned on the entire time, im @ 3.873v or 61%! granted, its been light usage its my secondary phone right now, but i am on the outskirts of service, and the week signal usualy sucks the battery...
ill update again , probably this time tomorow once it finaly dies...
<edit> as you can see in post #2, after 27 hours of up time, i still have higher battery voltage than what the phone was assuming was 100% on initial flashing of the rom...... just food for thought...
That's very interesting, t1h5ta3... Trying it right now, will edit post with results
<Quote>Killing tasks automatically immediately after closing them – this apparently makes battery life worse, because when a program is in RAM, it doesn't consume system resources, but when you run it again, it does. Thanks to hastarin for the clarification.<End>
Do not necessaryly agree. A 'program' is a collection of endless conditions and calculations that puts strain on the CPU. Unless a 'freeze program' function is built in to Android to literally freeze a program when its idle in ram the, the program will still continue to consume valueble cpu power just to stay idle albeit at a reduced rate. But having many program in memory in this state can tax the system performance draining the battery.
I don't have the file batterystats.bin in data/sytem!!!
Any help?
Edit: In fact i found it with root explorer search however i am enabling view of hidden files and i don't see it!
Does deleting it While in android by root explorer will cause any problem?!
@Life Engineer: Nope, I deleted it by Droid Explorer's console while having android up and running and nothing bad happened.
Slampisko said:
@Life Engineer: Nope, I deleted it by Droid Explorer's console while having android up and running and nothing bad happened.
Click to expand...
Click to collapse
BTW i don't agree saying that conservative is the best governor; i guess many accept with me; latest tests showed that interactive is the best and it worked for me!
You may consider putting it in the thread
@Life Governor: I was thinking about that too. Will edit thread.
Question when it comes to draining the battery which side do I drain it on win or Android?
@WCENIGHTCRAWLER: Android I suppose, as Android needs to know the correct voltage for drained battery.
Slampisko said:
@WCENIGHTCRAWLER: Android I suppose, as Android needs to know the correct voltage for drained battery.
Click to expand...
Click to collapse
I'm unsure on this as well. Maybe I'm a bit behind on all the dev that's happened. But I remember if draining battery in Android, it messes up with the build on the SD card.
Might give this a go tonight and see.
Just one simple question. When phone is in deep sleep, the cpu's running speed is the min frequency I choose from the cpu settings or a default lower one?
I use smart ass 2 with min at 768 and max at 1516 . So in deep sleep my phone is running at 768?
Thanks in advance...
Sent from my Huawei u8800 using XDA Premium App
spirosbond said:
Just one simple question. When phone is in deep sleep, the cpu's running speed is the min frequency I choose from the cpu settings or a default lower one?
I use smart ass 2 with min at 768 and max at 1516 . So in deep sleep my phone is running at 768?
Thanks in advance...
Sent from my Huawei u8800 using XDA Premium App
Click to expand...
Click to collapse
Not 100% sure but freq is minimum as it can be. And if cpu is not used no metter is freq 10000MHZ or 300Mhz it uses almost the same power. But when cpu is in use freq is important to power usage. Freq management is good not because it lowers freq but because it lets use lower freq on things that is not require hi freq. so it saves LITTLE LITTLE BIT of power. In idle mode (deep sleep) no meter what freq is.
But i still don't understand the need of governor. It's good only in cases where you overclock cpu but if don't - i don't see why it should be used.
PS Use app called CPU SPY it shows on what freq your cpu is being used and how much of the time.
Thanks! I use CPU SPY and it says tha about 60% or more is in deep sleep, 15%-25% is at 768 and the rest higher, which seems to be a good thing. But my phone still lasts for about 10-15 hours with normal use.
So i thought that maybe my min 768 frequency drain a lot of battery.
To clear things up a bit I use latest oxigen rom+latest franco kernel+zram+Juwe ram script...
Actually deep-sleep state is a special state supported by your phone MCU. In this state, a lot of functionality (therefore a lot of logical gates) are disabled thus MCU consumes very low power compared to normal functioning states. The thing about a CPU/MCU is when it is running even if there are no work to do no code to process, it has to run some command. While idle it must run NOOP (no-operand / no operation) command or do something equally unnecessary like counting a not required number. But in deep sleep mode, MCU actually stops working except for core functions to keep your phone going on.
Think about it this way, in a normal working state, CPUs most basic functionality is to read a command from memory, execute it and proceed to the next command to continue. Thus, in an operating system or a single purpose embedded software, CPU/MCU has to execute a "do nothing" command when you have no job to give it. But even a "do nothing" command need all of the MCU/CPU resources to be kept readily available. If you're sure that you have absolutely no job for your MCU/CPU to do, what you can do is to tell it to go and sleep fr a while until you wake it up again. In sleep, MCU/CPU can shut down a lot of its support systems like math processing, external memory access, graphics related functions (if any), even IO outputs. Depending on your CPU/MCU, this means until an interrupt occurs or a special sub system wakes it up, most of the sub-systems within your MCU/CPU thus may be millions of transistors will not be working so, your CPU/MCU will not consume as much power.
In layman's terms, deep-sleep state is a special state that shut down most of your MCU in your phone, thus while crippling it by removing its ability to function, making sure that it doesn't consumes much power. So OS (Android) (with the help of some additional hardware) controls when your MCU will sleep and under what circumstances it will wake. So it shuts down the engine -so to speak- when you're not using it for long terms and saving fuel rather than leaving your car on idle.
Hope this helps..
Thanks t_d_z. That is also how I imagined things...
But what is wrong with my battery which today, for example, went 33% down in 5 hours with 68% (from cpu spy) in deep sleep, without wi-fi on.
As i said above, I use latest oxigen rom+latest franco kernel+zram+Juwe ram script+smarass2 governor...
I also calibrated my battery by wiping battery stats, like i read in a post.
I have read in an other forum that if you use smartass (I use smartass2) or ondemand (I think...) governors, the governor is learning your habits and after a week you see the difference. Is that true?
Finally, can you guys who have "good" battery life, post your settings? (By settings I mean: rom, kernel, governor with cpu parameters, how you use the phone and everything else you think is important).
Thanks again...
I get about two days of battery life. I use Oxygen without any modifications. CPU is min. 245 (or something like that with 200, I dunno now) and max. is 800. Wifi is always on when I am home.
Try installing Oxygen-r1 and use it with a full battery, do not change anything and do not install too many apps. There will be apps that just won't stop running (like BBC or CNN app), I do not install those. Then you will see how long your battery lasts. If you just write some messages throughout the day and call somebody for 1-3 hours you should get about 2 days.
Then install your apps and test it again - maybe your apps are the problem.
spirosbond said:
Thanks t_d_z. That is also how I imagined things...
But what is wrong with my battery which today, for example, went 33% down in 5 hours with 68% (from cpu spy) in deep sleep, without wi-fi on.
As i said above, I use latest oxigen rom+latest franco kernel+zram+Juwe ram script+smarass2 governor...
I also calibrated my battery by wiping battery stats, like i read in a post.
I have read in an other forum that if you use smartass (I use smartass2) or ondemand (I think...) governors, the governor is learning your habits and after a week you see the difference. Is that true?
Finally, can you guys who have "good" battery life, post your settings? (By settings I mean: rom, kernel, governor with cpu parameters, how you use the phone and everything else you think is important).
Thanks again...
Click to expand...
Click to collapse
Look not at cpu spy but in battery usage to find out what drains your battery. And i can tell All roms are kinda lame in terms of battery, except CM7. In deep sleep it takes about 7% of battery in 10hours. I tried all roms but non of them was so efficient. But latest franco kernel (which i think even more improves cm7 rom) does not support cm7 right now, so i've attached older version if you would like to test cm7+franco kernel.
With normal usage of 50 sms and 30minutes of calls and sometimes wi-fi to download few apps and 20minutes on easy games my battery lats about 18hours. Whan only sms it lasts 30hours. depends how long lcd is on
Well, I'm not an expert on smart phone OSes but I'm an expert on embedded systems and micro controllers. If the designers are not really stupid (which I'm sure they are not) all the peripherals gets suspended when the main CPU goes to deep sleep mode. So, it is almost impossible for the phone to consume much power in deep sleep state. Most likely your phone consumes that power the rest of the time when it is not in sleep mode. I agree with Tommixoft, you should use battery usage info rather than CPU spy to find what drains your battery. Also, here is a quick check list about what consumes power :
1. Screen, especially when it is brightly lit
2. GSM network (Even when you're not talking to phone, GPRS/Edge/3G network communications drains almost as much power)
3. Wireless network
4. GPS
As an additional note, if your phone is not going to sleep mode regularly try to uninstall applications that have "prevent phone from sleeping" security setting.
Hope this helps, and of course there are a lot of more experienced people in the forum that knows about the details of the kernel so they might provide additional info.
Regards,
---------- Post added at 05:15 PM ---------- Previous post was at 05:10 PM ----------
Oh I forgot to tell the MOST important thing, 768MHz is way too high a value to set as minimal frequency. Try to set it 245. I use 122 MHz and it work pretty well. Don't forget, when you need the CPU power, the governor will provide it for you.
1. Abstract
2. Approach
3. Baseline configuration and results
4. References
5. Disclaimer
1. Abstract
Initially I was quite dissapointed with the battery life of the Samsung Galaxy S II i9100 with Android 2.3.4 out of the box. Coming from the Symbian world Nokia E71 I have been used to 6-7 days without recharging, while on SGS2 I got barely 1.5 days of normal usage. I started to optimize, and felt that the hardware is very capable for power saving, but the software is not optimized. After turning off all synchronization, going thru every program settings to switch to manual sync, switching to 2G network (EDGE in my area), turning off WiFi/Data/GPS/Background data I've got a busy day full of meetings at work (didn't touch the phone apart from 2 incoming calls and a few notes) and only 10% decrease of battery for 24h (100%->90%) which is amazing by itself. But I wanted to optimize more.
I have heard that other things like Custom ROM, freezing of system applications, task killers, Under Volting (UV), Under Clocking (UV) would help me too, but I was about to discover which one really helps in real use.
One lazy Sunday like today while being a bit sick allowed me to conclude an experiment of how far did I get in optimizing the power usage for a "baseline configuration" - WiFi/Data/GPS/Background data off, 2G network, all possible sync to manual - and the results are astonishing.
2. Approach
The approach to optimize the battery life is only one - PUT IT TO SLEEP AND DON'T LET IT AWAKE.
Having read a ton of articles on xda-developers.com and other places I have concluded that the strategy for optimizing includes these major steps:
2.1. Get a clean baseline Custom ROM where much of the "bloatware" is removed, so you have less to optimize - optional step but it helps to do it
This probably helps although not necessary. I'm not sure if the stock ROM will allow you to put custom kernels which will be needed in the next steps to optimize further.
But in any case you need to be at least "rooted" to apply some of the advice - either via a rooted kernel like CF-Root [8], or via an exploit like the DooMLoRD'a zergRush exploit [7].
2.2. Optimize the screen-on time
This is up to how frequently you use the phone
What you can optimize is to set a default "conservative" CPU Governor profile from 200MHZ to 1200MHz for regular usage - nothing really special, it's only slower on jumping to high frequencies.
If you have a kernel like RedPill Kernel [9] you can add an additional In-Call profile with "conservative" CPU Governor from 100MHZ to 800MHz - while you talk and phone to the ear it idles at 100MHz, but if you start a let's say Notes taking application, or go to turn on Bluetooth it will be snappy enough. Same holds true for listening to music or listening to books - but it's up to your imagination how to set a 100MHz profile in this case (maybe via Tasker). Have in mind that the 100MHz setting may be unstable on some phones because it's not standard, but mine is absolutely fine with that setting.
For setting the CPU profiles software like Voltage Control [5] (paid version for many profiles) is used.
CPU Governor "conservative" is crucial so you don't instantly jump to the highest frequency as it happens with the default "ondemand" governor (or its clones).
You can choose an I/O Scheduler appropriate for your CPU Governor based on the MagicConfig article in my references [14].
People also say that the following helps and I use it: turn off button LED lights, darker wallpapers, auto-rotation disabled, auto brightness on (I have to see the screen after all).
If you use kernel like RedPill Kernel [9] the button LED lights are undervolted by default, so you can leave them "on for 1.5s" for example.
If you have a Custom ROM like CheckROM Revolution HD V6 [10] with JKay Deluxe Settings you can set a Dark or Darker auto brightness profile - also usable to some extent.
One article in my references [12] also gives the power drain in milliwatts (mW) for each hardware device - go read it and you will understand how much the Amoled Display (Average - 370mW), LED lamp next to camera (1.3W), Camera (700mW), Bluetooth and GPS (110 to 180mW) etc. hardware actually consumes.
2.3. Optimize the screen-off time
2.3.1. Analyze Wakelocks
Wakelocks indicate when some application prevents the phone from going to sleep for some time. It does not necessarily mean that it does something significant at that time, and may be only a bad application design. Some applications really like to hold wakelocks periodically during the day for no reason, even if set to Manual sync etc. Examples of such applications are Facebook, 3G Watchdog... You milleage may vary but you can be sure that this hurts your battery life a lot. Any such application can be frozen with Titanium Backup or uninstalled if it's not a system application. Both count and total duration of the wakelocks are important.
BetterBatteryStats [1] has a screen to debug Partial Wakelocks and Kernel Wakelocks. You can also obtain the raw information via the console command "cat /proc/wakelocks".
2.3.2. Analyze Alarms
Alarms are a way to start jobs in the system at a predefined time. Many applications set alarms to get awaken and check/poll something before sleeping again. You should note that firing an Alarm is not necessarily connected to having a Wakelock - you can see many alarms firing but very few wakelocks. The problem is that too many applications set too many alarms for no reason. These activities also hurt your battery life a lot. Examples of such applications are Google Maps (at least for me)... As long as I have another GPS application with offline maps, I've simply frozen Maps with Titanium Backup. Another example was let's say Social Hub, but as long it was firing once per 24h, I didn't bother to touch it.
BetterBatteryStats [1] has a screen to debug Alarms which requires Root access. You can also obtain the raw information via the console command "dumpsys alarm".
2.3.3. Analyze Network Connections
If you get lost in the Wakelocks and Alarms, you can help yourself by checking what connections are kept alive while Internet is connected. OS Monitor [3] has a Connections screen which is equivalent to "netstat". This is also a good indicator what may be drawing unnecessary battery and respectively freeze/uninstall. In my case I can point that I've discovered that K-9 Mail had a bug with IMAP accounts - if I connect to an IMAP account set to manual/poll sync once, it keeps a connection open forever, until you restart or kill the process, but for POP3 account there is no problem... Being aware of such things really help with the battery life.
2.4. Optimize deep idle and sleep time
This is the most important goal in this article - how to get into deep idle/sleep and stay there, because this is the only real way to save energy on such a powerful device
CPU Spy [2] can show you how much time you spend in deep idle/sleep - with my baseline testing I've managed to get 99% deep idle/sleep which is amazing - only if the manufacturers gave us the phones in this state and we can build on that...! But it's the other way round.
Unfortunately the sleep mode on the stock kernel and the CF-Root kernel is not too deep. Entropy512 in my references [15] describes the following modes of idle/sleep:
IDLE - clock is gated but power remains (does not eliminate any static power consumption)
AFTR - clock is gated, CPU core power removed, cache power remains - this eliminates a great deal of static power consumption - cannot be entered if second core is active
LPA - AFTR + removal of cache power - cannot be entered if second core is active
IDLE is entered if the CPU is expected to be free for 4 msec (40 msec stock)
AFTR is entered if the CPU is expected to be free for 10 msec (disabled stock)
LPA is entered if the CPU is expected to be free for 40 msec (40 msec stock)
This compares to suspend, aka deep sleep, which takes around 150 msec to enter and 650 msec to resume, and the CPU must be at 800 MHz (or at least have enough voltage to support 800 MHz operation) during this time. Entering suspend/resume is very costly in terms of power due to heavy interrupt load.
Unfortunately my knowledge ends here, but flashing a kernel like RedPill [9] with Power Saving features and patches enabled improved the deepness of the idle/sleep very significantly, let's say 2 fold compared to the stock kernel. Sleep is entered faster and with more savings.
2.5. Optimize the modem/baseband
If all the points above are done, you can consider some savings from trying to flash newer modem/baseband compatible with your Custom ROM for better power savings during Calls and Data transmission. I did not get deep into this yet, but it's rather a big Voodoo, because the contents of the various modems are not public and you can only read feedback like "works very good for me" and "totally awful", which is not very scientific. Initially you can try staying with your original modem or the one provided by the Custom ROM, and optimize the previous points.
2.6. Optimize other stuff
2.6.1. Under Volting - will probably help, but for every frequency you need to choose voltages that are not too low to keep the phone stable. You can try the UV profile from the MagicConfig article from my references [14].
2.6.2. Under Clocking - I consider trying to use 100MHz useful for some scenarios, but only as an additional profile. After all the phone is very powerful and snappy to cripple it with 100MHz-1000MHz profile as default.
2.6.3. Automatic Task Killers - absolutely worthless peaces of software [16]. Android OS is good at power saving. It is very power saving conscious actually, of course combined with capable to sleep hardware. The only reason to kill a process is if it locked on holding some resource/connection forever, and OS Monitor [3] can kill it.
2.6.4. Battery charging - charge the battery as frequently as you want, but be sure to not keep it constantly on high charge (90-100%) [18], as long as this is not a good state for storage. Making bigger cycles helps to maintain better battery life. Some sources say cycling from 0% to 100% is not optimal [17], but from my experience through the years this way also works good for battery longevity, and maintaining small loss of capacity. I can give an example of losing up to 10% of battery capacity per year compared to design capacity with this method. You can view such statistics in Power Management tools in Lenovo ThinkPads etc.
Note that the battery indicator has some tweaks around 100% so consider the following:
- When charging for me it hops from 98% straight to 100%. If you disconnect now, it drops to 98% again, and this is what other people complain from too. Just wait some more time and it will charge to real 100% to have more battery life.
- The indicator stays at 100% longer than at any other value. So when testing, always test from the same baseline, e.g. always charge to 100% before comparing results.
3. Baseline configuration and results
CheckROM Revolution HD V6 PDA XWLA4 (Android 2.3.6) + modem XXKI4 (was XWKL1 but changed for no reason) + kernel RedPill 1.3.
WiFi/Data/GPS/Background data/Auto-rotation/Button LED lights - OFF
Any type of Sync or Polling - OFF/MANUAL, using local Contacts and local Calendar
Widgets - AccuWeather.com on MANUAL and Today view from Calendar.
Network: 2G (EDGE in my area)
Background and lock screen: Dark wallpapers
CPU default profile: conservative 200MHz-1200MHz
CPU in-call profile: conservative 100MHz-800Mhz
Because I don't want to wait a full day for the statistics, I'll post now for 8 and 12 hours, and tomorrow add for 24 hours.
(See the attached images, because I'm not sure how to embed them in the text)
4. References
[1] BetterBatteryStats XDA Edition - http://forum.xda-developers.com/showthread.php?t=1179809
[2] CPU Spy - https://market.android.com/details?id=com.bvalosek.cpuspy
[3] OS Monitor - https://market.android.com/details?id=com.eolwral.osmonitor
[4] Titanium Backup (paid version) - http://matrixrewriter.com/android/
[5] Voltage Control - https://market.android.com/details?id=com.darekxan.voltagecontrol
[6] Android Terminal Emulator by Jack Palevich - https://market.android.com/details?id=jackpal.androidterm
[7] DooMLoRD's Easy Rooting Toolkit [v4.0](zergRush Exploit) - http://forum.xda-developers.com/showthread.php?t=1321582
[8] CF-Root Kernel - http://forum.xda-developers.com/showthread.php?t=788108
[9] RedPillKernel_Rev1.3 - http://forum.xda-developers.com/showthread.php?t=1288850
[10] CheckROM Revolution HD V6 - http://forum.xda-developers.com/showthread.php?t=1312240, http://checkrom.com/
[11] Premium Dark Wallpapers - http://forum.xda-developers.com/showthread.php?t=1474798
[12] Kernel Governors, Modules, I/O Schedulers, CPU Tweaks - http://forum.xda-developers.com/showthread.php?t=1369817
[13] Getting the Most out of the Battery on your Android device - http://softbanksucks.blogspot.com/2011/10/getting-most-out-of-your-battery-on.html
[14] MagicConfig for UV and CPU Governor + I/O Scheduler combinations - http://forum.xda-developers.com/showthread.php?t=1466017
[15] Entropy512 explained CPU idle states - http://forum.xda-developers.com/showpost.php?p=23252902&postcount=17
[16] Android Task Killers Explained - http://lifehacker.com/5650894/andro...ed-what-they-do-and-why-you-shouldnt-use-them
[17] Li-Ion Battery Charge Cycles, Voltages and Storage analysis - http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries
[18] IBM/Lenovo recommendations on Li-Ion battery treatment - http://forum.xda-developers.com/showpost.php?p=23258191&postcount=19
5. Disclaimer
Paid apps are mentioned here for clarity. You can of course find an alternative if such exists. Free (no ads) versions of software were listed where possible.
Needless to say that all advice here must be applied only under your own responsibility.
Results at 25h usage: The battery indicator has dropped down to 94%.
However it's a bit hard to predict how much is it going to last this way as long as after initially staying at the value "100%" the indicator decreases a bit faster.
See attached screenshots.
Thanks for the detailed post but i still don't understand why people insist on having a smart phone and then turning off any good feature in it to get 2 days of work out of it.
Agent_Adodas said:
Thanks for the detailed post but i still don't understand why people insist on having a smart phone and then turning off any good feature in it to get 2 days of work out of it.
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Click to collapse
That depends if you dont want xxxx app running every day why run it and why let it connect on a daily basis . Its a Smartphone not a dumbphone that controls the user .Nothing in the Smartphone design says hey guy you are really uncool if you don't have everything turned on .
I turn on what i want when i want but then again i am not sad enough to live my life on facebook .
jje
there's nothing wrong with killing background tasks that eats your battery, but to me it looks funny to turn off WIFI, 3G, Sync or polling.
anyway, that's what i think, other people may think different and will prefer to save on battery life.
Agent_Adodas said:
there's nothing wrong with killing background tasks that eats your battery
Click to expand...
Click to collapse
:facepalm:
http://lifehacker.com/5650894/andro...ed-what-they-do-and-why-you-shouldnt-use-them
Unless you love using terribly coded apps.
This is a Baseline - my initial starting position. Yeah I don't feel cool for running tons of unneeded stuff Actually after 15 hours of uptime I feel pretty bad and a slave of the charger.
I hope to tell more people in a single post what can be optimized, stripping off any superstition, voodoo and some pointless beliefs circulating in the web
I don't say "do like me", but instead what a great hardware SGS2 + core Android software actually seems to be
Please also note I didn't limit myself to 1000MHz, do not recommend reducing voltages etc... the struggle is to put the software in control, not to cripple the experience.
Additionally, I have WiFi at work, at home, at the gym, and between them I'm driving... for that reason I don't need unlimited data. And for new mails I actually get SMS and know when to fetch the mail. If it's important I can turn on the data as well. On business trips abroad there is no unlimited data anyway too - only WiFi at the office and at the hotel. So there are different scenarios...
Serious Observations Bro!
Must say, very clear,simple and awesome way to put together things...will try this out and post again!
Thanks a ton bro! Love the efforts and for helping us out!
Great tips mate... I knew many of them before but i will not use them so much.. I have a feeling that it criples my phone... Limiting my usage of the phone... Instead i have a custom rom,custom kernel ,an extra standard battery,car charger...
I even tryed once to apply most of your tips but they gave me a couple of hours extra batt life. My problem is network signal coverage-edge is fine(but who can surf on egde ?!? ) ,3g and hspda signal is not so good (i travel a lot by car all over my country) and the phone keeps trying to get better network signal and uses more battery...
So most of your tips work if u want to criple your phone and if ur network has great coverage...
Sent from my GT-I9100 using XDA
Using a slow scaling cpu governor defeats the purpose of battery savings. You want something that will scale up fast and scale down just as fast. That way the task gets completed quicker and the cpu can go back to an idle state faster.
Slower governors take longer to complete a task and that uses more battery.
I rather OnDemand complete something in 2 seconds jumping immediately to 1.2Ghz than Conservative in 4 seconds scaling it's way up each step and then scaling back down slowly.
Sent from my GT-I9100 using Tapatalk
Elisha said:
Using a slow scaling cpu governor defeats the purpose of battery savings. You want something that will scale up fast and scale down just as fast. That way the task gets completed quicker and the cpu can go back to an idle state faster.
Slower governors take longer to complete a task and that uses more battery.
I rather OnDemand complete something in 2 seconds jumping immediately to 1.2Ghz than Conservative in 4 seconds scaling it's way up each step and then scaling back down slowly.
Sent from my GT-I9100 using Tapatalk
Click to expand...
Click to collapse
Not true if I'm typing notes. Ondemand will struggle to take me on high frequency, while I'm browsing the texts... Do you need high frequency when reading forums?
Actually I have no problem to play Asphalt 6 and Angry Birds on 1200MHz with this setup
It takes you more cpu cycles to get Asphalt or Angry Birds fully loaded with Conservative than it would with OnDemand.
And you have to remember we have dual-core cpus. It's to your benefit to get both cores scaled up faster to finish the task.
You don't notice this as much because the difference is probably in the milliseconds. But Conservative is more of a power hog than OnDemand.
Sent from my GT-I9100 using Tapatalk
Wow, thats massive and informative! Too good job Sir! Hats Off!
Elisha said:
It takes you more cpu cycles to get Asphalt or Angry Birds fully loaded with Conservative than it would with OnDemand.
And you have to remember we have dual-core cpus. It's to your benefit to get both cores scaled up faster to finish the task.
You don't notice this as much because the difference is probably in the milliseconds. But Conservative is more of a power hog than OnDemand.
Sent from my GT-I9100 using Tapatalk
Click to expand...
Click to collapse
Agree. All that advice is mostly targeted to battery conscious people, this is not a gaming setup There is no one best configuration for all.
It's also not about what exact values to choose, but what approach to take for battery life improvement.
Can't wait to run a UV kernel once the sources drop. That there helps quite a bit to conserve battery.
Sent from my GT-I9100 using Tapatalk
I know pretty much all of this already but it's a useful guide for noobs for sure.
I don't bother anymore with SetCPU or any of that anymore and to be honest it's had little or no impact on battery life which is still excellent.
gingingingin said:
0: IDLE - CPU not clocked
1: AFTR - something not totally clear to me, but an alternative way to IDLE the CPU - ARM Off Top Running with L2 cache keeping its state
2: IDLE+LPA - IDLE + DEEP IDLE - also some parts of hardware are powered down
3: AFTR+LPA - AFTR + DEEP IDLE
Click to expand...
Click to collapse
These are not deep sleep states. Deep sleep is also known as "suspend" - where almost the entire system is shut down.
These are CPU idle states, which allow the core to save power even when the system is "running". They take significantly less time and energy to enter, but save less power. Also, there are only three of them - IDLE, LPA, AFTR. See arch/arm/mach-s5pv310/cpuidle.c in the kernel source for more details.
As an example, with kernels that have the cpuidle backport from the Tab 7 Plus:
IDLE is entered if the CPU is expected to be free for 4 msec (40 msec stock)
AFTR is entered if the CPU is expected to be free for 10 msec (disabled stock)
LPA is entered if the CPU is expected to be free for 40 msec (40 msec stock)
There are some rules that can cause lower states to be entered even if the cpuidle governor chooses LPA or AFTR. (cpuidle governor has nothing to do with cpufreq governor).
Your descriptions of the states are pretty close to what I understand them to be:
IDLE - clock is gated but power remains (does not eliminate any static power consumption)
AFTR - clock is gated, CPU core power removed, cache power remains - this eliminates a great deal of static power consumption - cannot be entered if second core is active
LPA - AFTR + removal of cache power - cannot be entered if second core is active
The above are why 100 MHz is pointless on our device, and in my experience, actually can increase power usage. The achievable voltage difference between 100 MHz and 200 MHz is insignificant for most peope, and if the voltages for two frequencies are the same, it's better to run at the higher frequency and drop into AFTR/LPA to shut off core power more often. The PDF linked from Ezekeel's post at http://forum.xda-developers.com/showthread.php?p=21785924#post21785924 is a useful read on this topic, especially section 6. While it's fairly old, most of the concepts remain valid. For this reason, 500 MHz also doesn't consume much more power than 200 for a given fixed amount of load due to having the same voltage stock as 200 (however, it does increase some internal clocks I believe, leading to slightly increased power) - so when the screen is on I have it set to 500 MHz minimum.
This compares to suspend, aka deep sleep, which takes around 150 msec to enter and 650 msec to resume, and the CPU must be at 800 MHz (or at least have enough voltage to support 800 MHz operation) during this time. Entering suspend/resume is very costly in terms of power due to heavy interrupt load, which is involved in 90% of complaints about high "Android OS" battery usage on Gingerbread. However I believe from some of the testing I've run that improved cpuidle greatly reduces this penalty.
With the improved cpuidle patch, even when I use the Wake Lock app to hold a permanent wakelock for testing purposes, my standby drain is only 1.5%/hour or so. When not holding a wakelock, 0.5%/hour on wifi is easily achievable. It gets much worse at my desk at work, where the signal is weak and the cell radio eats huge amounts of power - there it's around 1%/hour.
Edit: As to task killers - all of the people saying "task killers are worthless" talk about memory management only. The fact is, unfortunately, that there are some crappy apps out there that use too much CPU or hold insanely long wakelocks that you just have to use occasionally. Facebook is still the #1 example here - Facebook is a major battery hog, therefore when you're done with it, you must kill it with fire. However, NEVER use an autokiller and never use it for memory management!
Regarding battery charging, I wonder have you read this article before : batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries (please add http)
The fact seems to be completely opposite from your theory in 2.6.4.
Sent from my GT-I9100 using xda premium
Not sure, the battery article is a bit doubtful. For me at least the testing sequence is strange:
1. Charging current of 1C is a bit high, to say the least. Quick chargers have never been optimal for any type of batteries.
2. Discharge current of 1C is huge and far from being realistic for a mobile phone.
Also if we interpret the results it becomes that at 10% DoD we get 4700 small cycles, which is close to 100% DoD with 500 big cycles... Actually the results are in favor of the 100% DoD.
Of course my interpretation can be wrong, but so far I have got the opposite idea of that.
For practical purposes I can give an example of a Nokia Li-Ion battery thoroughly fully discharged and for 2 years it retained at least 80% capacity. I'd estimate the number of cycles to be 120-150.
On my current laptop the ThinkPad Panasonic battery was always almost completely discharged via settings, attaching screenshots. At 328 cycles and 3.5 years since first use it retains 88% of the design capacity. This is quite a good achievement for a tortured battery I'd say
Note: See the advice/sentence written in the top box by my good old IBM manufacturer (now Lenovo). "... battery deterioration may occur faster if the battery is constantly charged at 100%. Lowering the charge thresholds ... will help increase its lifespan". These guys know their job... I think their sentence almost surely relates to storage though. Storage at 50% is much better than storage at 100% charge. There is room for interpretation again.
Note: This is my second battery on this laptop, the first one Sanyo was a bit worse with the same treatment (maybe older technology) and after 2 years its electronics suddenly failed, while at around 150 cycles.
Entropy512 said:
The above are why 100 MHz is pointless on our device, and in my experience, actually can increase power usage. The achievable voltage difference between 100 MHz and 200 MHz is insignificant for most peope, and if the voltages for two frequencies are the same, it's better to run at the higher frequency and drop into AFTR/LPA to shut off core power more often.
Click to expand...
Click to collapse
First of all, thanks for the detailed explanation of the states.
I remember from the school/uni that the power used is proportional to the frequency. If we have static consumption in the chip it will not be affected by changing the frequency, but the dynamic part of the consumption is essentially doubled when running on 200MHz compared to 100MHz. I don't know the ratio dynamic_consumption:static_consumption for my chip, but it may be around 1:1.
The formulas were something like that: http://forums.anandtech.com/showthread.php?t=119229
Battery Calibration/Improving Battery life
Requirements:
Device needs to be rooted "Obviously".
Need to have Rom Tool Box Lite or Rom Tool Box Pro.
Some Basic Knowledge on how to use the app.
Note: Turn off Wi-Fi, Bluetooth, GPS, and Auto-sync if they are not in use. Hold down the notifications bar to disable them and activate the Power Saving mode which will make the device conserve energy under low battery state.
Battery Calibration Procedure.
1. Use your phone until the phone battery drains out completely and device gets switched off
2. Switch on the Device to make sure battery really is 0%.
3. Now plug in charger (Device turned off, Dont turn on the device)& leave it for charging until it reaches 100%
4. When the battery is full, switch on the phone, unplug the charger & check if the battery drops by 1 or 2% immediately.
5. If you notice battery drops immediately plug in charger once more (while the phone is on) & let it charge completely.
6. Once charging to 100% is done, don't disconnect the charger, open your root explorer, Provice RW permissions.
7.Search for 'DATA' Folder then 'SYSTEM' Folder.
8.In the 'System' folder you will find 'batterystats.bin' delete this file.
9.Exit Root Explorer and Use your phone normally unless it completly drains the battery(Dont connect your charger)
10.Power On your device and charge your device untill it reached 100%
11.Now you should enjoy the Samsung long Battery Life!!
Note: These methods are not permanent this worked for me so sharing with you.
Greenify your Apps:
NEW: Non-root working mode is now supported in 2.0+, Greenify is a convenient utility that will consequently hibernate battery hoarding applications that wait out of sight after you're done utilizing them.
Google Playstore & Thread
Titanium Backup:
Great battery life, wonderful execution and cool customization— we have seen one or more applications for these things. Presently we should see an alternate must have and a standout amongst the most evaluated applications for established Android gadgets. On the off chance that you got root benefits on your gadget, Titanium Backup is an exceptionally suggested application for you. You may discover various reinforcement applications at the Google Play Store, however none of them does the employment so splendidly and pleasantly.
Google playstore
The KERNEL can do some important things to help with battery saving as it is the controller of all things working in your phone:
1. Underclocking - if you feel your phone is fast enough, go ahead and lower the maximum frequency of your CPU, it will save power as the faster the CPU goes, the more energy it uses.
2. Undervolting - it's more complicated; every CPU requires certain amount of supplied voltage to run and the amount increases with the speed of CPU (clock frequency). For example 200Mhz requires only 0.9V while 1600Mhz requires 1.25V by default. The thing is, the higher the voltage, the higher the heat and of course power consumption. So the best way to lower it is to lower voltage - Samsung had to set voltage at the high enough level that every CPU they produce would work correctly but every CPU is different and some of them allow for lowering voltage and still remaining fully stable thus using less power to do the same work. Typically you can save about 0.05V but some CPU will allow as much as 0.1V to be saved. The same really goes for our GPU part, it can be undervolted as well. There are other parts in our phone that can be undervolted, like memory or controllers of various part but I have found (well in my phone) that saving were very small and caused instability so I would not recommend playing with them. We could think about undervolting our display as it is the biggest consumer of energy in our phone but actually we are doing it all the time The voltage supplied to the screen decides its brightness so if we were to lower the voltage it would just get dimmer
3. There are small savings to be had in various other parts controlled by the kernel:
- first and second thing are tied with SDcard - using it carries high power requirements - the less we use it, the better. Now we can't reduce to completely as all our data, apps and whole system is on it but we can reduce it's use by setting various caches.
a) read cache for internal and external SD combined with scheduler that minimizes reads and writes - so far the best scheduler created specifically for mobile SD use is FIOPS, so using that with a large buffer (maximum of 4096) is actually the best from energy standpoint.
b) system swap space - some kernels allow for creating a very specific kind of swap space, Android will use it once the free memory falls below certain point. Normally this swap space would be placed on SDcard but in this case it's inside a specific region of RAM. Why it is created like this? Because it can be easily compressed to keep more data, so basically we are using Android mechanisms and compressing memory so we can run more apps and keep them in physical RAM That means they are accessible faster than if we were to read them from SDcard and they use less power. Compressing and decompressing data as they go in and out of swap space is still far less energy consuming process then reading them from SDcard.
- third is governor configuration - governor is a system service that decides at what frequency should the CPU be working at every moment and how much cores should be enabled - this of course has great impact on energy consumption and on the smoothness of our experience with our phone. There are two schools of setting up governor and they base their decisions on two premises:
a) sharply increase CPU speed to get the work done fast and sharply decrease speed once it's not needed.
b) slowly increase speed and only so much to do what must be don then slowly decrease speed once you are done because you may have to do something again in a moment
There are pros and cons of both ways - way A means jumping to high frequency for a short time but high frequency uses comparatively large amount of energy, way B means slow increase but also means remaining in intermediate states for longer actually using energy for longer. I don't have any way to actually measure the resulting energy consumption but way A has a distinct advantage of creating much smoother experience so I use that myself.
- fourth is hotplug configuration - our CPU can dynamically enable and disable additional cores - the process is called hotplugging. Some governors are created specifically for controlling this process, the best, as far as I have tested, in this is Lulzactiveq. Hotplugging has to be wise as to the IF and WHEN to enable and disable additional cores, it measures how many "packets" of data are in queue to be processed and based on short history anticipates increase and decrease of workload.
All those interesting options are configured in scripts created for main contemporary kernels: Nadia, Devil and Agni and available HERE.
Latest OC / UV Scripts for Devil / Agni and Nadia Kernels for Note 2 are HERE
Guide to EXT4 to F2FS migration for Note 2 is HERE
CourtesyMat9V
Reserverd
very useful info , thanks :good:
rraaka said:
very useful info , thanks :good:
Click to expand...
Click to collapse
Your welcome :good:
Very briefly stated.
Thanks for sharing
I read all your posts, This will help me in my next configuration for Emotion V7, Nadia with mat's script.
Now on Emotion V6 ....AGNi Pure Stock v4.2.2
yogi909 said:
Very briefly stated.
Thanks for sharing
I read all your posts, This will help me in my next configuration for Emotion V7, Nadia with mat's script.
Now on Emotion V6 ....AGNi Pure Stock v4.2.2
Click to expand...
Click to collapse
Glad you liked it.
The android system, unlike other OS's actually displays the battery reading from a written data config, known as battery stats in general. While there is, in perception no disadvantage to this method of reporting the average remaining battery life, it isn't the actual battery life you are getting, but the percentage read from your daily usage and then sends the information to the OS for displaying the battery life. Due to this, you can have the percentage misreported, so it is suggested to factory reset every 6 months on stock unrooted and if rooted wipe battery stats using rom toolbox free/pro every 2 weeks to ensure correct reporting of your battery life.
Note - This won't increase battery life, but will ensure correct reporting of battery percentage, which gets messed up quite quickly on custom roms(for some unknow reason).
Undervolting can cause battery drain or better battery life depending on your configurations, if you have the CPU set to running high many of the times(like from a governor or background apps that need regular wakelocks for syncing content) it will slow down the ramping up of frequencies during deep sleep(no effect when screen on) and thus it will hold a longer wakelock for the purpose, so undervolt carefully depending on your usage - mild to mid(medium to high undervolt), mid to high(low to medium undervolt), heavy(low to no undervolt).
Different governors have different scaling methods for CPU, thus will give better or worse battery life depending on your config and usage. A governor ramping up faster and scaling down slower will give better battery life in scenario of heavy usage because the device can go to deep sleep state faster and perform background syncs in an instant; while someone with low to mid(or a bit high also) would like to have a governor that ramps up slower and scales down slowly too so as to complete the syncing of files and media scan(if running) and make the device perform smoother and go into deep-sleep and remain in the state for longer times(though going to DS mode will be a bit slower than a fast downscaling governor) and will occasionally wake up for background syncs, but those will be longer, but won't have much effect on battery life because of lower frequencies being used and syncing complete before high frequency threshold is reached.
Depending on what a user needs for his daily usage it is a good idea to keep the rest of apps(preferably facebook, musixmatch, instagram and shazam) hibernated using something like greenify(which now supports auto-hibernation without root in the beta versions). Auto sync should only be enabled for apps that need it, like E-Mail, Google+, Gmail etc.and rest should be set onto manual sync.
Samsung has a habit of throwing in a lot of features onto their device, so keeping motions enabled, which you don't even use, except for a show-off, is a bad idea because it will drain battery. Exploring the settings menu to disable unneeded things can pay-off as a positive fruit for patience.
Keeping the storage clean is also a good way. A corrupted or highly filled up storage requires more passes to be read and thus keeps the media scanner process running for longer, which puts a strain on the battery life. Also, android OS is based of the 32-bit kernel of linux(for now, 64-bit is planned to be introduced after some time), so the media scanner has to look for data linearly in the storage blocks on the internal and external SD, unlike 64-bit where the data is arranged into random blocks which are then brought together as one and the media scanner can be informed of the address of the blocks due to more threads allowed to be run for same process and also a higher memory bandwidth allocated to each process so as to make it perform faster. Due to this reason, the media scanned isn't informed of all the addresses on the time of data writing and thus has to scan linearly looking for bits of data. So keep the storage clean and minimal. Cloud is a good way if you have decent internet and won't need access to the files stored there in regular period of times.
If using a custom rom make sure that it either comes with the modem for your region or flash the modem of your region after that, so as to ensure better signal stability and thus better lasting battery life. A correct modem can give more dBm of signal at the same place as compared to a wrong one.
A good way to have stable battery life is to enable power saving mode in areas with low signal and when on low battery life only, keep it disabled otherwise or it will slow down the race-to-idle for Deep sleep mode and hence cause a bit more battery drain just before deep-sleep state.
Having location services enabled all the time isn't a good idea either, use it only when needed and keep GPS off otherwise. Samsung allows toggling of most things from notification panel so use it.
Smart stay, smart pause, smart scroll all use the front camera for detection, which requires high voltage for operation(separate from CPU, uncontrollable by software) so keep them off unless needed.
Make sure to keep your device clean. How does this affect battery life? Dust and other things when collected around pins, sockets and connectors prevent efficient passing of electricity and thus forces the device to demand more energy, around half of which is taken away by these. Even metallic dust can have adverse effect due to it making the transfer more rapid and forcing the battery to supply the power, which is most probably wasted.
Automatic brightness is good during daytime, but useless during late evening and night, because brightness level doesn't need to be changed and it keeps the light sensor activated. Disable it after 7 Pm(you can also set up tasker or some other automation tool for this).
An Odexed rom provides more battery life as compared to deodexed, but at the cost of available customization as no mods will work and will instead crash the file related to them. Choose your side wisely and patiently.
If you're going to use some app, check if it uses GCM for providing notifications(usually google search at your service), if not look for an alternative which does. GCM doesn't even use marginal amount of battery and is more efficient in providing the notifications at time and also doesn't need a persistent notification.
Check for wakelocks thoroughly and remove the misbehaving apps or hibernate them if you need them on your device. Also, be sure to update the apps for receiving any fixes and optimizations, which can sometimes also decrease the required wakelock frequency for an app and thus preserve battery life.
Don't keep too much of auto updating widgets on homescreen, these only serve to drain the battery further by auto syncing.
if rooted, use Xposed and boot-manager to disable unneeded apps at boot time and thus preserve battery and time required for full boot-up.
If on a custom kernel use DAC direct(if available) for sounds. This bypasses the output mixer and thus preserves a little bit of battery required to produce and refine the sounds, instead utilize 128x oversampling and FLL tuning for an even better quality.
Don't reboot on a regular basis unless needed, this will eat up battery life quicker.
Don't use any task killer( a long debate on uselessness of those can be found on many sites, with a simple google search), the Android system's LMK is itself more than enough.
Be sure to research carefully on what you really need and what you don't and then use it. Don't go on downloading useless things which you'll delete later on because it creates a small entry in /data/data which gets scanned by media scanner due to being present in its path and thus will make the process longer and more battery hungry.
Some custom kernels allow for controlling deep sleep type. Usually these types are already defined in the kernel tweaking app itself. A person with heavy usage should use the IDLE deep sleep more so the device is able to wake up quickly and doesn't drain much battery in case of many wakelocks. Similarly a light user will benefit with AFTR+LPA due to CPU deep sleep, but this isn't advised for medium to heavy usage(use IDLE+LPA instead) because the wakelocks require a high power to even wake up the device, which will drain more battery if you use your mobile more, because many apps will try to acquire a partial/complete wakelock.
I know this is quite long, but read through carefully and you'll surely get better battery life.
Source : Experience and Google groups
Good knowledge
Thanx
cartmanez said:
Good knowledge
Thanx
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People are still spreading the batterystats.bin myth? *facepalm*
This has been totally and utterly disproven many, many times, including by core Android developer
So delete away. It doesn't calibrate or improve your battery life though.
I cannot study myself all technically like you what you mentioned in "[Experience][Share]My Usage and Testing of Custom kernels for Touchwiz Kitkat".
But above is well informative and now i get why i was getting worse battery life & longer wakelock by OC and UV with selective governer.
By testing different setting in AgniPureStock 4.2.2 today i reach 25 hr + battery life with my moderate usage.
I am sure above valued information, i will get most out of my battery.
Thank you very much KNIGHT97 for sharing.
aukhan, Hi mate, do i need to install greenify too?
botski said:
aukhan, Hi mate, do i need to install greenify too?
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Yes
Sent from my GT-N7100 using Tapatalk
aukhan said:
Yes
Sent from my GT-N7100 using Tapatalk
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if i use greenify i need to install xposed framework too?
botski said:
if i use greenify i need to install xposed framework too?
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Xposed is optional. It is only for the experimental features. However, the developer has got 1 or 2 of those working without Xposed in the latest beta(you'll need to join the greenify G+ community for getting the beta, though)
Sent from my RPG with auto targeting
非常有用的信息，谢谢 ：好：
thanks for the info man.....its very helpful
aukhan said:
The KERNEL can do some important things to help with battery saving as it is the controller of all things working in your phone:
1. Underclocking - if you feel your phone is fast enough, go ahead and lower the maximum frequency of your CPU, it will save power as the faster the CPU goes, the more energy it uses.
2. Undervolting - it's more complicated; every CPU requires certain amount of supplied voltage to run and the amount increases with the speed of CPU (clock frequency). For example 200Mhz requires only 0.9V while 1600Mhz requires 1.25V by default. The thing is, the higher the voltage, the higher the heat and of course power consumption. So the best way to lower it is to lower voltage - Samsung had to set voltage at the high enough level that every CPU they produce would work correctly but every CPU is different and some of them allow for lowering voltage and still remaining fully stable thus using less power to do the same work. Typically you can save about 0.05V but some CPU will allow as much as 0.1V to be saved. The same really goes for our GPU part, it can be undervolted as well. There are other parts in our phone that can be undervolted, like memory or controllers of various part but I have found (well in my phone) that saving were very small and caused instability so I would not recommend playing with them. We could think about undervolting our display as it is the biggest consumer of energy in our phone but actually we are doing it all the time The voltage supplied to the screen decides its brightness so if we were to lower the voltage it would just get dimmer
3. There are small savings to be had in various other parts controlled by the kernel:
- first and second thing are tied with SDcard - using it carries high power requirements - the less we use it, the better. Now we can't reduce to completely as all our data, apps and whole system is on it but we can reduce it's use by setting various caches.
a) read cache for internal and external SD combined with scheduler that minimizes reads and writes - so far the best scheduler created specifically for mobile SD use is FIOPS, so using that with a large buffer (maximum of 4096) is actually the best from energy standpoint.
b) system swap space - some kernels allow for creating a very specific kind of swap space, Android will use it once the free memory falls below certain point. Normally this swap space would be placed on SDcard but in this case it's inside a specific region of RAM. Why it is created like this? Because it can be easily compressed to keep more data, so basically we are using Android mechanisms and compressing memory so we can run more apps and keep them in physical RAM That means they are accessible faster than if we were to read them from SDcard and they use less power. Compressing and decompressing data as they go in and out of swap space is still far less energy consuming process then reading them from SDcard.
- third is governor configuration - governor is a system service that decides at what frequency should the CPU be working at every moment and how much cores should be enabled - this of course has great impact on energy consumption and on the smoothness of our experience with our phone. There are two schools of setting up governor and they base their decisions on two premises:
a) sharply increase CPU speed to get the work done fast and sharply decrease speed once it's not needed.
b) slowly increase speed and only so much to do what must be don then slowly decrease speed once you are done because you may have to do something again in a moment
There are pros and cons of both ways - way A means jumping to high frequency for a short time but high frequency uses comparatively large amount of energy, way B means slow increase but also means remaining in intermediate states for longer actually using energy for longer. I don't have any way to actually measure the resulting energy consumption but way A has a distinct advantage of creating much smoother experience so I use that myself.
- fourth is hotplug configuration - our CPU can dynamically enable and disable additional cores - the process is called hotplugging. Some governors are created specifically for controlling this process, the best, as far as I have tested, in this is Lulzactiveq. Hotplugging has to be wise as to the IF and WHEN to enable and disable additional cores, it measures how many "packets" of data are in queue to be processed and based on short history anticipates increase and decrease of workload.
All those interesting options are configured in scripts created for main contemporary kernels: Nadia, Devil and Agni and available HERE.
Latest OC / UV Scripts for Devil / Agni and Nadia Kernels for Note 2 are HERE
Guide to EXT4 to F2FS migration for Note 2 is HERE
CourtesyMat9V
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Thanks man....you rock:good::good:
What about using Juice Defender (available in play store)? I used the basic one first and then ended up buying ultimate because I saw good results. Now the location (using cell tower) based WiFi enable/disable extends my battery life significantly.
The is one of the first apps I install once I feel a new flash is stable.
If you have the Samsung "Toolbox" utility, that floats a button on the screen to access your choice of five apps from anywhere - turn it off. It causes the "security storage" process to peg at 20% all the time the screen is on if "Toolbox" is enabled. When "Toolbox" is disabled, "security storage" process drops to a couple of percent when the device is idle. There's quite a saving on battery drain.
Battery calibration
I have a rooted Nook HD+ running Android 7.1 and I decided to calibrate its battery.
I ran it down to zero as recommended then attached it to the mains.
All I have had for several hours is a black screen with just the charging symbol (battery with lightning inside it). Nothing else, no progress bar, no charge %, nothing Androidy.
Is this as it should be and should I just wait for several more hours or is there something wrong?
Many thanks.