I got 12% battery drain in 17 hours, standby. I'm not a pro at android but I might give a little tut. on how to save battery life to the max. Atleast, it works for my P500 so it should work for you & for any other android device as well.
Uninstall every unnecessary app, including system apps (those apps, that does not mess up with the system stability - If you uninstall Email app, you will not solve your problems with Gmail app).. same with Messaging. That said, leave as minimum apps in the background as you can. App killer does not solve this problem, it just closes bg apps - they restart after some time. I'm using ATK (Advanced Task Killer), It usually kills 1 - 3 apps, so.. I have a minimum of apps running in the bg.
Basic stuff.. turn off your 3G, wifi, bg sync, gps when not in use. If you need to check your email, use 2G network only option, not 3G. Use 2G always when you don't need 3G speed. Screen brightness is not that important if you set it to anywhere below 70%. It should not drain the battery that fast.
Setcpu - profiles - governors--
My profiles are as follows
Charging - 480min - 748max
Battery <90% - 245min - 600max
Battery <70% - 245min - 600max (U can live with one profile for the battery, I have 2 in case I want to change the 2nd profile)
Screen off - 122min - 245max -- This is what saves my battery in standby.
The governors are ondemand for usage & conservative for screen off.
I'm using Void.echo rom with tapps & gapps modules, uninstalled everything I don't need.
I hope this helps If anyone has a better idea on how to save battery life, please share yours as well.
Thanks for your post, but actually most background apps don't drain battery. I have made lots of experiments (removing system aps, preventing autorun etc., and I don't see any major difference in battery life. So now, I'm on stock 2.2 and I'm now at 80% after almost 30h use: about 20 min talk, 10-15 min wi-fi (mail), 10-15 min EDGE. The latter by the way drains battery more than wi-fi. So instead of messing with system apps I recommend putting the phone in airplane mode during the night and as mentioned in the above post - not using 3G when not needed (EDGE has decent speed).
thats the why linux works !!! use all the memory u possibly can...These Microsoft *****es have changed the way computers were supposed to be used not reinstalling windows and other crapware all the time..Switch to Debian while its still time
And i use these settings
screen off 245-245 powersave (otherwise phone gets hot Its summer in india)
600-245 ondemand otherwise
kopchev said:
Thanks for your post, but actually most background apps don't drain battery. I have made lots of experiments (removing system aps, preventing autorun etc., and I don't see any major difference in battery life. So now, I'm on stock 2.2 and I'm now at 80% after almost 30h use: about 20 min talk, 10-15 min wi-fi (mail), 10-15 min EDGE. The latter by the way drains battery more than wi-fi. So instead of messing with system apps I recommend putting the phone in airplane mode during the night and as mentioned in the above post - not using 3G when not needed (EDGE has decent speed).
Click to expand...
Click to collapse
If there are many apps running in the bg, phone runs out of ram, so it tries to free up some space constantly. I think that drains battery, not the apps themselves. As well as the more cpu power is used, the faster it drains battery. Airplane mode shuts off any connection, so either that or you could just shut down the phone during night. Hmm you could tell me how to prevent app autorun, i have not looked into that.
btw juicedefender does wonders with the phones battery i had a 2% percent over night normal mode (not airplane) no 3g/Edge/Wifi/Bluetooth active and just sleeping
sarfaraz1989 said:
thats the why linux works !!! use all the memory u possibly can...These Microsoft *****es have changed the way computers were supposed to be used not reinstalling windows and other crapware all the time..Switch to Debian while its still time
And i use these settings
screen off 245-245 powersave (otherwise phone gets hot Its summer in india)
600-245 ondemand otherwise
Click to expand...
Click to collapse
True about windows & linux hehe. You havent tried 122-245mhz on screen off? Ofcouse, it lags even when i receive an sms, it's something like this - the screen turns on, then after 2 sec. i hear a notification, then after 1 sec. i see the sms but that does not make any problems for me, it's extreme powersaving
I don't get the point of airplane mode while you're sleeping.
If you don't want to get calls while sleeping, shouldn't it be better if you turn off the phone?
I had a good experience with JuiceDefender until now too. Last night my phone was 100% and no airplane mode while sleeping. It drained only 3%.
SoundTone said:
If there are many apps running in the bg, phone runs out of ram, so it tries to free up some space constantly.
Click to expand...
Click to collapse
From what I've read, Android doesn't swap. It'll just kill the background apps on it's own. I don't think there even is a swap unless you root, rom and create one on your uSD.
rapharias said:
I don't get the point of airplane mode while you're sleeping.
If you don't want to get calls while sleeping, shouldn't it be better if you turn off the phone?
I had a good experience with JuiceDefender until now too. Last night my phone was 100% and no airplane mode while sleeping. It drained only 3%.
Click to expand...
Click to collapse
It's more convenient, because the on/off process is quite slow...in contrast - airplane mode on/off is 3-4 secs. In airplane mode you can still use wi-fi. Last night the battery drained only 1%
i read somewhere that changing the CPU speed doesnt change the voltage, thus it does not affect battery life... anyone can confirm this???
As far as I can remember from school, a logic gate uses more power when switching, thus a higher frequency would also mean higher power drain (higher frequency = more switching of the logic gates), without voltage modification.
Voltage is changed in order to keep stability - higher voltage means a more stable logic signal, and a faster switching gate, and thus people reccomend using a higher voltage for higher frequencies/lower voltage for lower frequencies.
Thus, a CPU with so many logic gates does not operate just like a simple resistor. In fact it is worse, because when you use higher voltage AND higher frequency power drain is increased much more.
On the other hand, most modern CPU's simply deactivate CPU regions when idling, so, in case of our hardware (constant voltage) there should not be such a great difference when idling (most of the CPU is powered down). The only thing is for the phone to be REALLY idling (no background tasks eating too much of the CPU when screen off).
Basically, what this means is that if you want extreme power saving use a governor with 128MHz minimum and have as few background services as possible (or at least the ones that are there should be optimized for the least CPU usage).
Now I use the standard governor (248 - 600) and I thing my idle power drain is OK.
I guess I will test a governor that is plain 600MHz and one wit 320 or 480 as a minimum, in order to see if power drain is higher when using a lower lag configuration.
And, just as a guess, if background tasks are triggered by timers, a governor with just 600MHz (or 320 - 600 or 380 - 600?) could (just a wild guess) mean that background tasks take less time to execute, and leave the CPU to si more in IDLE mode, causing a very similar power drain as an extreme power saving governor. But this is just a guess, i have not tested it yet. And it also depends on what apps you have (what the apps do when phone is sleeping).
Basically, my best advice would be to watch the apps (after you install a new app, wait for a night to see if the new app causes a higher drain; if it does, search for another app that does the same thing)
spaic said:
As far as I can remember from school, a logic gate uses more power when switching, thus a higher frequency would also mean higher power drain (higher frequency = more switching of the logic gates), without voltage modification.
Voltage is changed in order to keep stability - higher voltage means a more stable logic signal, and a faster switching gate, and thus people reccomend using a higher voltage for higher frequencies/lower voltage for lower frequencies.
Thus, a CPU with so many logic gates does not operate just like a simple resistor. In fact it is worse, because when you use higher voltage AND higher frequency power drain is increased much more.
On the other hand, most modern CPU's simply deactivate CPU regions when idling, so, in case of our hardware (constant voltage) there should not be such a great difference when idling (most of the CPU is powered down). The only thing is for the phone to be REALLY idling (no background tasks eating too much of the CPU when screen off).
Basically, what this means is that if you want extreme power saving use a governor with 128MHz minimum and have as few background services as possible (or at least the ones that are there should be optimized for the least CPU usage).
Now I use the standard governor (248 - 600) and I thing my idle power drain is OK.
I guess I will test a governor that is plain 600MHz and one wit 320 or 480 as a minimum, in order to see if power drain is higher when using a lower lag configuration.
And, just as a guess, if background tasks are triggered by timers, a governor with just 600MHz (or 320 - 600 or 380 - 600?) could (just a wild guess) mean that background tasks take less time to execute, and leave the CPU to si more in IDLE mode, causing a very similar power drain as an extreme power saving governor. But this is just a guess, i have not tested it yet. And it also depends on what apps you have (what the apps do when phone is sleeping).
Basically, my best advice would be to watch the apps (after you install a new app, wait for a night to see if the new app causes a higher drain; if it does, search for another app that does the same thing)
Click to expand...
Click to collapse
I don't know about CPU's as much as u, but simple logical thinking helps here.. Low frequency + minimum of bg tasks = great power saving, I have now used the phone for 36hours without charge, 61% battery left. That is not only idling, i write about 50 to 150 sms a day & use the phone for other stuff too. So, those governors & frequencies i mentioned earlier in this post, helps a lot.
fransisco.franco thinks otherwise read the his post that contains the link to his rom devoid.francov6(ROM is cool btw and unfortunately i have a slow sdcard )
I think the first post is by far the best I have seen so far.
Sent from my LG-P500 using Tapatalk
Wow, only 1% all night?
I'll take a deeper look at your tips!
I use devoid.franco with franco.kernel v12. From all ROMs I've isntalled, it's the best: great performance and long battery life.
I get 5% battery drain in 7:30 hours (at night), without doing anything special, without running a custom ROM and without uninstalling apps. I just make sure GPS, Bluetooth, WiFi and data are off before going to bed.
So ive been told that underclocking or undervolting might actually harm battery life instead of helping it by making the process slower before it completes.
What are the best set cpu settings for battery life?
If i decide I dont want to use setcpu how can i restore the default values?
Search for the setcpu thread by lennyuk.
All your answers are in there. Sorry don't have the link but you will find it. Think it might be in android development and hacking section??
Edit:
http://forum.xda-developers.com/showthread.php?t=1158102
Sent from my GT-I9100 using XDA App
digitallysick said:
So ive been told that underclocking or undervolting might actually harm battery life instead of helping it by making the process slower before it completes.
What are the best set cpu settings for battery life?
If i decide I dont want to use setcpu how can i restore the default values?
Click to expand...
Click to collapse
UC/UV/OC can harm your phone if not properly taken care of.
Each cpu is different so there is no 'best settings'. If i share my settings, it might not be stable in your phone, or may be you can undervolt more than me which means your cpu can handle lower voltages better than mine.
You can use an init.d script (if your kernel supports) or SetCpu or Voltage Control to overclock/underclock/undervolt.
First thing, search through kernel threads and find a kernel you think suits your taste best.
Next, using setcpu or voltage control, set a min and max global frequency.
Now for each frequency lower the voltage by 25 mv (from stock). Keep doing this until your phone becomes unstable or hangs. Use the last settings that didn't cause any problems.
I have a profile which works only at night
from 11pm to 6 am 500mhz with power save.
Once i tried 1000mhz conservative, for the whole day, does seem to give me more battery life at the end of the day.
ProNewb said:
I have a profile which works only at night
from 11pm to 6 am 500mhz with power save.
Once i tried 1000mhz conservative, for the whole day, does seem to give me more battery life at the end of the day.
Click to expand...
Click to collapse
Shouldn't the phone be in deep sleep (200mhz) at night? If you're not using it ofcourse.
TheSaw said:
Shouldn't the phone be in deep sleep (200mhz) at night? If you're not using it ofcourse.
Click to expand...
Click to collapse
Deep Sleep doesn't mean locking on to lowest frequency supported by kernel. (200 mhz on stock).
Deep sleep is the state where both cores shut off, and system (O.S) goes to sleep, governor stays idle, etc etc. There will be some background processes running too, but cpu is not using 200 mhz throughout deep sleep.
EDIT: Or you meant a screen off profile.
TheSaw said:
Shouldn't the phone be in deep sleep (200mhz) at night? If you're not using it ofcourse.
Click to expand...
Click to collapse
The phone should be in deep sleep, but some apps don't let the phone sleep at night thanks to there inefficient coding.
Anyway it does seem to use less battery, without this profile, I loose around 9% in 6 hours, but now I loose only 4-5%.
Sent from my GT-I9100 using XDA App
digitallysick said:
So ive been told that underclocking or undervolting might actually harm battery life instead of helping it by making the process slower before it completes.
What are the best set cpu settings for battery life?
If i decide I dont want to use setcpu how can i restore the default values?
Click to expand...
Click to collapse
just unistall setcpu and then reboot your phone and then you go back to default values
Can some tell me about deep sleep? And how to activated?
Sent from my naughty Xperia Ray.
it is automatic, when you turn screen off.
download cpu spy app from market and see how long youc phone is in this state (deep sleep), usually its most of the time.
alexlaveline said:
Can some tell me about deep sleep? And how to activated?
Sent from my naughty Xperia Ray.
Click to expand...
Click to collapse
Deep sleep is to save your battery when the phone is in idle. It should be the lowest freq that the cpu is "stable" and as a result the voltage can also be really low.
Kriomag is right, most of the time deep sleep is automatic (but it can be turned off)....look in your build.prop for these lines:
pm.sleep_mode=1
ro.ril.disable.power.collapse=0
They will help help your phone go to sleep....
If you set your min cpufreq too high your phone also will have trouble going to sleep....if you undervolt too much you also may have stability issues entering and leaving sleep...and this will also be affected by your choice of governor.
If all this is set up correctly your phone should be really sleepy and you can monitor this with cpuspy, the on board battery stats (the phone should not wake up unless the screen is on), and with better battery stats.
justmpm said:
Deep sleep is to save your battery when the phone is in idle. It should be the lowest freq that the cpu is "stable" and as a result the voltage can also be really low.
Kriomag is right, most of the time deep sleep is automatic (but it can be turned off)....look in your build.prop for these lines:
pm.sleep_mode=1
ro.ril.disable.power.collapse=0
They will help help your phone go to sleep....
If you set your min cpufreq too high your phone also will have trouble going to sleep....if you undervolt too much you also may have stability issues entering and leaving sleep...and this will also be affected by your choice of governor.
If all this is set up correctly your phone should be really sleepy and you can monitor this with cpuspy, the on board battery stats (the phone should not wake up unless the screen is on), and with better battery stats.
Click to expand...
Click to collapse
Thanks for the explanation, this increase my knowledge.
Kriomag said:
it is automatic, when you turn screen off.
download cpu spy app from market and see how long youc phone is in this state (deep sleep), usually its most of the time.
Click to expand...
Click to collapse
Sent from my naughty Xperia Ray.
Hey guys,
I did an experiment not a long time ago. I have my old phone with 4.1.2 Android and I went on a trip for a few days. Typically my phone discharges after 12-15 hours even without using anything (old battery) with smartassv2 or just conservative mode. Before going on the trip, I've set the minimum clock to the lowest possible and set the mode to powersaving (always using the minimum). And after 3 days the battery still was at 86%.
So what's the problem with the Android OS itself? Or have I just gotten some magical experience? Why does it use such a large clock rate for the processor when it's locked and using any preference script apart from power saver?
Thanks a bunch!
First of all, battery life depends on your battery type and capacity.
Second of all, when you underclock your cpu to the minimum frequency, battery consumption will decrease a LOT but using this frequency for apps use is practically impossible.Also, display causes less battery life.
Hope i helped !
Forgot about this topic. Yes, mate, I understand that, but the minimum frequency is enough when I don't have any apps running in the background. Seems like android still has a lot of power managment programming to be done under standby.
Maybe I wasn't clear enough, but if you just use any governor (with minimal frequency set at the lowest) apart from "powersaving", it will use more power on standby, then powersaving with the minimal frequency set.
Hi Guys,
I am a noob here. I have never used a android phone before, not even a iPhone - so basically no smart phones.My first smart/android phone would be Nexus 4 which would be coming tomorrow.
I have been reading threads to understand andriod architecture and believe have understood to certain extent.
I have a question in clocking the CPUs and Voting.
As I understand, we have 3 states -Max, Min and Sleep for a single CPU core
Max - The frequency (clock speed) which CPU executes or maximum speed which CPU sends signals to its components and get the response back. This would be used when the system is on - which means when user is doing some process.. like texting, video chat, gaming (this case GPU is also involved) etc.
Min - This would be for background process when the user/phone is idle - that when screen is off (eq - gmail sync, facebook sync etc..)
Sleep - Screen off and no background process , the core will be in sleep.
And the battery level will be directly propotional to speed of CPU with respect to the volting.
Now lets say there is a single core processor in a phone which can clock upto 1.5GZ. and the stock kernel comes up with Max - 1.3GZ and MIN -0.5 GHZ.
Question is abt overclocking minimum frequency
1. why not overclock the Mn frequency to 1.3Ghz? because the backgroundprocess would be fast and phone/core will be sleeping after that,
which means process consumes more battery at that particular time but overall baterry should be efficient as there would be more sleeping time.
2. About volting, so far I have not seen min and max volting. So is there only one voltage/power drawn for max and min CPU speeds by CPU?
Please correct me if any of my statements is wrong.
Appreciate your help,
Thanks,
Franklin B.
Overclocking the minimum frequency to 1.3ghz would probably decrease your processor's life if you use your phone too much but I have been actually increasing my phone even 200mhz more than it was in stock ROMs, i've been using my device for more than 2 years and it still works perfectly. Finally, it all depends on how much your phone is good.
I also decreased the cpu min and max frequency when phone sleeps to 256 mhz which decreased a lot battery consumption.
Hope i helped !
Don't forget the THANKS button
1.you can but your battery life will be drastically reduced! There is a good amount of time after the screen is off and before the phone sleeps! So if over clock the min to 1.3Ghz, the processor will be running at 1.3Ghz till it goes to sleep! But if that's what you want you can do that!
2 . I'm not so sure about this topic either but I think the processor operates at a particular voltage and I could be wrong!
Sent from my GT-P3100 using Tapatalk 2
Thank you Guys
Franklin Bernard said:
1. why not overclock the Mn frequency to 1.3Ghz? because the backgroundprocess would be fast and phone/core will be sleeping after that,
which means process consumes more battery at that particular time but overall baterry should be efficient as there would be more sleeping time.
2. About volting, so far I have not seen min and max volting. So is there only one voltage/power drawn for max and min CPU speeds by CPU?
Click to expand...
Click to collapse
Hi, I received your PM. I agree with the guys about the heat issues, longevity, and battery life etc. The answer to your question #2 will help you better understand things.
In all kernels, there are frequency/voltage scaling tables. For every frequency step (clock speed) in the table, it corresponds to a specific voltage. It gets a bit more complicated than this of course, but that is the basic way things are setup in the kernel. The higher the frequency, the higher the voltage is required to be to keep the CPU (or GPU, bus, RAM etc.) stable at a given clock speed. The more voltage, the more current, and the more heat is generated. The longer you stay at higher clock speeds/voltages, the better the cooling system you need to have. Supply regulators are defined to feed the core and rail voltages so that the processor can live in a happy environment no matter what it is being asked to.
As far as power consumption, it's all about getting a unit of work done in a timely/efficient fashion using the least amount of power consumption. If the phone is sleeping, the word "timely" takes on a different meaning so then it is mostly concerned with power consumption and getting the background tasks completed effectively without having the phone experience the sleep of death (SOD). What you are talking about is the theory of "race to sleep" so that the work can be done quickly and the phone can go back to sleep where it uses the least amount of power (clocks actually turn off during deep sleep and cores are turned off). However, there is a happy medium to this theory and heat and battery consumption are the main enemies. Heat can also rob efficiency, more current is required when a circuit heats up. The more a phone wakes up to do syncs for email, apps, social networking, missed calls etc., that work can stack up throughout the day. The question comes down to how can the device get this work done using the least power and keep the device cool. On the N4, the lowest frequencies can use ~700-800mV per core while the highest frequencies can use ~1100mV. There is a drastic difference in the amount of heat generation between this range.
I think this should give you the general idea and maybe more that you wanted to know! Here are some links to check out if you are interested. Google and you will find many many more articles and research papers.
http://en.wikipedia.org/wiki/Voltage_and_frequency_scaling
http://atrak.usc.edu/~massoud/Talks/Pedram-dvfs-Taiwan05.pdf
Thanks a ton !!!