Develop Bugs

Screen brightness and battery life.

I have been searching for 20 mins and can't find an answer (first time using the app so may have missed something).
I was wondering if anyone had any data on brightness % and power usage. People seem to go to great lenghts to change the brightness levels but I remember something on last years Google dev. con. videos on YouTube that said it didn't make as much difference as originally thought. (i can't find the video either lol. Bad search day here).
Sent from my HTC Desire using XDA App

The biggest improvement in battery life (IMO) comes from setcpu. I also keep my screen at 40% which I suppose helps some. I've got a Mugen extended life battery and setcpu set at around 537 max (on demand) with the screen off. I get 2 days out of my battery... And I use my phone a lot.

k3an said:
The biggest improvement in battery life (IMO) comes from setcpu.
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Click to collapse
Lol, now uninstall it, set smartass governor and see how meaningless that app really is.
madmaveric said:
I was wondering if anyone had any data on brightness % and power usage.
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Click to collapse
The bad thing is that on Sense roms, I have yet to see brightness going lower than 30%, even in pitch dark. Aosp does far better job as long as brightness is concerned. Setting it at low value is not an option for me either as it renders your phone unusable in direct sunlight.

/accidental double post

erklat said:
Lol, now uninstall it, set smartass governor and see how meaningless that app really is.
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Click to collapse
How to set governor when i don't have an app which can do this any more?
Swyped from my HTC Desire using XDA App

MatDrOiD said:
How to set governor when i don't have an app which can do this any more?
Swyped from my HTC Desire using XDA App
Click to expand...
Click to collapse
Every rom has it listed under its changelog, usually it is smartass for sense roms. It isn't by accident either, some have reported lag waking the phone up. I haven't across almost all roms available, and even if I did I'd still prefer 20% less performance over 20% less battery life.

madmaveric said:
I have been searching for 20 mins and can't find an answer (first time using the app so may have missed something).
I was wondering if anyone had any data on brightness % and power usage. People seem to go to great lenghts to change the brightness levels but I remember something on last years Google dev. con. videos on YouTube that said it didn't make as much difference as originally thought. (i can't find the video either lol. Bad search day here).
Sent from my HTC Desire using XDA App
Click to expand...
Click to collapse
Why dont u test it wiht currentWidget or so? Okay, i did it:
0% -> 125mA
25% -> 150mA
100%-> 280mA
So what do we learn? Brightness and/or Screen has a big impact and probalby most people here trying kernel tweaks and whatever to improve the battery dont understand math.
MatDrOiD said:
How to set governor when i don't have an app which can do this any more?
Click to expand...
Click to collapse
You can just use the Terminal... its linux after all.

x潮騒x said:
Why dont u test it wiht currentWidget or so? Okay, i did it:
0% -> 125mA
25% -> 150mA
100%-> 280mA
So what do we learn? Brightness and/or Screen has a big impact and probalby most people here trying kernel tweaks and whatever to improve the battery dont understand math.
You can just use the Terminal... its linux after all.
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Click to collapse
Agree. Just check the battery usage, you will get the idea.
On mine, display usually uses 40% - 60%, with data always on.

Apologies for the late reply. lost internet connection for a week then forgot I posted it
Thanks for the replies guys. I eventually found the video, took ages lol
(youtube.com/watch?v=OUemfrKe65c).
According to what they say in this the screen actually doesn't account for that much of the total battery usage (mainly due to the screen being off most of the day) overall given everything else using battery.
i.e. coming up with a way to keep the device asleep for longer when turned off would completely out strip any adjustment to the screen brightness in terms of battery life.
So things like lower cpu when in standby can be really good but only when not getting data transfer (as this needs to be done very quickly as its expensive).
As adjusting screen brightness is easy to do I think that is why so much time is spent on this. In reality though it seems like it is only going to give a limited battery life increase.

But if you put low cpu, the cpu needs more time at low to do the same that a fast cpu, thats why the setcpu apps its a bit crap. I think that set low the brightness of the screen save more battery than putting the set cpu really low... (just my two cents)

I leave the brightness on my phone to around 30% for better battery, and i can see it ok in the daytime. I have recently had it up at 100% and noticed how quick my battery goes dead.

Gsanez said:
But if you put low cpu, the cpu needs more time at low to do the same that a fast cpu, thats why the setcpu apps its a bit crap. I think that set low the brightness of the screen save more battery than putting the set cpu really low... (just my two cents)
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Click to collapse
Very true.
I guess ideally you want the CPU low when its not doing anything and high when doing data transfers etc (to speed up the high current draw activities).
I guess a good app would be one that puts the phone in airplane mode for 90% of the time when inactive. Only coming out once every so often to check for text/data etc. I can see that giving better returns than anything else. from what was said in the video a phone in standby doing nothing would apparently last nine days (as apposed to one normally). Given this data I guess its possible to double the battery life with this kind of app.
I may have to have a go at writing one

SMF_12 said:
I leave the brightness on my phone to around 30% for better battery, and i can see it ok in the daytime. I have recently had it up at 100% and noticed how quick my battery goes dead.
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Click to collapse
I agree that turning the brightness down makes sense and saves battery. It just seems a disproportionate amount of time people spend over brightness vs better ways of extending battery life.
I guess the rewards also depend on the amount of time you use the phone as the more you use it, the better reward from the screen and the less from the standby solutions

better battery life

I've been using CyanogenMOD 7 and love it (mostly). The one thing I don’t like about it is the short battery life. I'm kind of new to rooting phones so it took me a bit to get it rooted and get CM7 rolling. I was wondering if there are any mods out there like CM7 that have better battery life? Or if there's any thing I can add to CM7 to give it more batter life?
I've been using android since the first phone came out so I’m already knowledgeable in what to turn off to try and extend the battery life, but I have noticed a big decrees in batter since installing CM7.
Thanks for the help guys
Trench

You can under clock the processor when your phone is asleep. This creates better battery life.
Sent from my HTC Vision using XDA App

Have you tried wiping battery stats?

evilcuber said:
You can under clock the processor when your phone is asleep. This creates better battery life.
Sent from my HTC Vision using XDA App
Click to expand...
Click to collapse
your phone automatically underclocks your processor when it sleeps (for most CPU governors), you do not need to tell it to do so.
I'm not picking on you fyi, I'm just making sure we are giving people accurate information... there's only one thing worse than no information: incorrect/incomplete information.
op: which version of CM7 are you running? remember, the more minimal your setup (ie less homescreens, less widgets, manual syncing of gmail and whatever else, etc) the better your battery life will be. this is especially true of newer phones that are getting heftier cpu & gpus that, while intelligent with power consumption, are going to drain even larger capacity batteries relatively quick with moderate/heavy usage.
how long are we talking with battery life? how heavy a user are you? for reference, I get around 16 hours of battery life if I don't charge the phone at all from unplugging to battery dying with moderate to heavy usage (texting ~50 times a day, sometimes up to 100 emails depending on what's happening at work, couple hours of calls, couple hours of streaming music [pandora or audiogalaxy], couple of hours of games [peggle and plants v zombies mostly - both of which are resource hogs], etc).
I have just learned to get used to the fact that the phone is going to die if I use it a lot, so I've purchased three micro-usb cables and a car charger.. that way, unless I'm in an area where there is no charge-capable usb port nearby, I'm always able to get a little more juice if need be.

pmcqueen said:
your phone automatically underclocks your processor when it sleeps (for most CPU governors), you do not need to tell it to do so.
I'm not picking on you fyi, I'm just making sure we are giving people accurate information... there's only one thing worse than no information: incorrect/incomplete information.
op: which version of CM7 are you running? remember, the more minimal your setup (ie less homescreens, less widgets, manual syncing of gmail and whatever else, etc) the better your battery life will be. this is especially true of newer phones that are getting heftier cpu & gpus that, while intelligent with power consumption, are going to drain even larger capacity batteries relatively quick with moderate/heavy usage.
how long are we talking with battery life? how heavy a user are you? for reference, I get around 16 hours of battery life if I don't charge the phone at all from unplugging to battery dying with moderate to heavy usage (texting ~50 times a day, sometimes up to 100 emails depending on what's happening at work, couple hours of calls, couple hours of streaming music [pandora or audiogalaxy], couple of hours of games [peggle and plants v zombies mostly - both of which are resource hogs], etc).
I have just learned to get used to the fact that the phone is going to die if I use it a lot, so I've purchased three micro-usb cables and a car charger.. that way, unless I'm in an area where there is no charge-capable usb port nearby, I'm always able to get a little more juice if need be.
Click to expand...
Click to collapse
but i also mean setting the max sleep to 368mhz. by default its set at 800mhz. sometimes with apps running in the background, the processor may go to 800mhz without you knowing

check out 'powersave' and set your cpu max to 806mhz. should last you a nice long time like that. responsiveness suffers, of course.
'ondemand' and 806mhz is the best comprimise for me. still fine with HDvideo recording, streaming audio, Nav, etc
if you really want to make it last... clock down to 400mhz, turn off all the sync, set brightness and timeout to minimum, all the radios off (airplane mode), and the volume down, on vibrate.
;-)

pmcqueen said:
your phone automatically underclocks your processor when it sleeps (for most CPU governors), you do not need to tell it to do so.
I'm not picking on you fyi, I'm just making sure we are giving people accurate information... there's only one thing worse than no information: incorrect/incomplete information.
op: which version of CM7 are you running? remember, the more minimal your setup (ie less homescreens, less widgets, manual syncing of gmail and whatever else, etc) the better your battery life will be. this is especially true of newer phones that are getting heftier cpu & gpus that, while intelligent with power consumption, are going to drain even larger capacity batteries relatively quick with moderate/heavy usage.
how long are we talking with battery life? how heavy a user are you? for reference, I get around 16 hours of battery life if I don't charge the phone at all from unplugging to battery dying with moderate to heavy usage (texting ~50 times a day, sometimes up to 100 emails depending on what's happening at work, couple hours of calls, couple hours of streaming music [pandora or audiogalaxy], couple of hours of games [peggle and plants v zombies mostly - both of which are resource hogs], etc).
I have just learned to get used to the fact that the phone is going to die if I use it a lot, so I've purchased three micro-usb cables and a car charger.. that way, unless I'm in an area where there is no charge-capable usb port nearby, I'm always able to get a little more juice if need be.
Click to expand...
Click to collapse
But some govenors don't drop the sleep to the lowest profile. In fact almost all keep it above the lowest clock. Other kernels allow it and you can also use third party to set it lower. When the tweaKr script becomes universal it will be even better =)
Sent from hells ghost chili mexdroid

ohgood said:
check out 'powersave' and set your cpu max to 806mhz. should last you a nice long time like that. responsiveness suffers, of course.
'ondemand' and 806mhz is the best comprimise for me. still fine with HDvideo recording, streaming audio, Nav, etc
if you really want to make it last... clock down to 400mhz, turn off all the sync, set brightness and timeout to minimum, all the radios off (airplane mode), and the volume down, on vibrate.
;-)
Click to expand...
Click to collapse
It suffers in powersave because it stays at the lowest setting only. No reason to set to 806. Lol and that bottom comment is hella funny =), but if he does that his phone will just be...a waste of pocket space.
Your best bet is to do some research on kernels. If you are using cm7 to cm 7.0.3 id recommened pyros kernel. If you are on 7.1 or a nightly over 121 I believe id go with eugene's streamline5. It did wonders for mine Also there is a battery saving tips. Google G2 battery saving tips. Should be first link that comes up.
Cyanogenmod roms are known to be battery hungry. Nom nom nom.
Sent from hells ghost chili mexdroid

cjward23 said:
Have you tried wiping battery stats?
Click to expand...
Click to collapse
I used the battery califration app if that's what you mean.
Thanks for all the help guys, i'll check out some Kernals.

popimp315 said:
Your best bet is to do some research on kernels. If you are using cm7 to cm 7.0.3 id recommened pyros kernel.
Click to expand...
Click to collapse
Do you have link for this? I'm running 7.0.3.. but I dont think im finding the correct Kernal.

Mugen 3600mah = better battery life...

Can you elaborate on what kind of battery life you are getting now? How many hours, and for what level of usage?
How long have you been on CM? It takes a couple charge cycles of the battery after flash any ROM, for the battery meter to be accurate. Clear battery stats (as mentioned) then charge to 100%, let drain to about 20%, repeat a couple times. Don't drain until the phone dies. Some people say to do this, and its not good advice. Over discharge of Li ion batteries can cause them to no longer take a charge. There are people on here, on the Vision and other phones, that let their battery drain to empty, then the phone would no longer boot, forcing them to replace the battery.

Mog said:
Mugen 3600mah = better battery life...
Click to expand...
Click to collapse
It has good battery life but the battery sticks out a lot and its very uncomfortable
Sent from my HTC Vision using XDA App

evilcuber said:
It has good battery life but the battery sticks out a lot and its very uncomfortable
Sent from my HTC Vision using XDA App
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Click to collapse
Yup its all opinionated. I would never go back to stock.
Sent from my T-Mobile G2 using XDA App

trench619 said:
Do you have link for this? I'm running 7.0.3.. but I dont think im finding the correct Kernal.
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Click to collapse
Dev section
Sent from my HTC Vision using XDA Premium App

Large Battery Drain on bananacake's kernel (0.4)

I'm experiencing a very big battery drain when the screen is off for a long time. I just left the phone screen off for 2 hours because I took a nap. When I woke up, the battery went from 60% to 40%. (via Juice Plotter) That was 10%, per hour, while screen off. I did not experience this from the AcesMod v35 original kernel. My SetCPU profile for screenoff was 128-345Mhz, smartass V2. Could this be the problem?
Thanks in advance.

I'll give you the best piece of advice concerning changing CPU frequencies.
.......................................................
Don't.

bortak said:
I'll give you the best piece of advice concerning changing CPU frequencies.
.......................................................
Don't.
Click to expand...
Click to collapse
This.
Deleting setcpu will be a move of your life.

erklat said:
This.
Deleting setcpu will be a move of your life.
Click to expand...
Click to collapse
Can i ask whats wrong with setcpu then?

A) Android manages it's CPU frequencies absolutely fine by itself.
B) By running SetCPU, it constantly needs to monitor your phone for it's state, so it can change the CPU frequency, which will just use more battery.
C) Overclocking your CPU will kill it faster.

Battery Life Optimization Guide

Rule 1: If you haven't taken these steps, you haven't done a thing in the way of actually optimizing your battery life, and please do not complain that your battery is bad if you haven't at least done steps 1 and 2!
Step 1: Use BetterBatteryStats: http://forum.xda-developers.com/showthread.php?t=1179809
This will diagnose battery drain issues. If you have apps that are sucking battery in the background, this will show it. Google the ones that have high partial wakelock, and usually you will get a diagnosis. It is also sometimes very easy to figure out what is sucking battery just by looking at the application that is holding wakelocks or having many alarm wakeups.
Step 2: Sync settings, make sure that all of them are either at push or as high as you're personally willing to allow between sync checkups. Any sync settings that happen too often will trash battery life.
Step 3: Radio based drain is a very big part of battery life! As such, if you do not need constant sync, you can turn off mobile data on your own when you do not need it, or go to the Mobile Network settings and disable always on mobile data. This can greatly increase battery life, but at the expense of sync not working when mobile data is off.
Step 4: Display brightness can greatly affect the power drain of the battery! You can either manually control the brightness, download Lux autobrightness to make your own autobrightness settings, or flash a custom autobrightness setting in the ROM in order to achieve this. It also can have the side effect of making the display of the right brightness when in the sun and in the dark, so it is always at ideal brightness to preserve battery.
Step 5: Make sure that the battery is calibrated. This is not very complicated. Download currentwidget from the market, put it on a homescreen. Charge the device until currentwidget indicates 0 mA charge. Use the phone until the phone shuts off. You might want to then go to hboot and drain the battery until it shuts off again, and then do a full charge again. Only do this once every 2-3 months, because this is bad for the battery.
Step 6: Adblocking! One big cause of battery drain and unnecessary network usage is downloading ads. If rooted, use Adaway and Adblock to block ads from ever being downloaded, and use Adaway's adware feature to detect and remove apps with adware!
Step 7: A radical step is to use Core Control or something similar to either underclock, undervolt, or just shut off cores. Undervolting is always highly suggested, as it will help reduce heat and give the phone a longer lifetime, but underclocking and shutting off cores will reduce performance!
Step 8: Custom ROMs and kernel experimentation might yield just a bit more in the way of battery life, and also give much more customization and features.
After this, you have likely topped out all that can be reasonably done to extend battery life. If you find that your battery drain is still poor, perhaps you have a defective battery, or maybe even a defective device (Highly unlikely, but who knows...). It is also possible that you simply have a use case that is much more than the phone can accomplish, in which case you can either use a battery case, or an external battery to charge the phone on the go.

Hunt3r.j2 said:
Step 5: Make sure that the battery is calibrated. This is not very complicated. Download currentwidget from the market, put it on a homescreen. Charge the device until currentwidget indicates 0 mA charge. Use the phone until the phone shuts off. You might want to then go to hboot and drain the battery until it shuts off again, and then do a full charge again. Only do this once every 2-3 months, because this is bad for the battery..
Click to expand...
Click to collapse
Weird, I've tried this many times, and can't get the indicator show exactly 0 mA...
the lowest for me around 3-5 mA... :|

what do you mean by undervolt because i dont understand..what are the consequences ?

nemer12 said:
what do you mean by undervolt because i dont understand..what are the consequences ?
Click to expand...
Click to collapse
if too much undervolting the phone freezes/ reboot ....so the best value for undervolting is between 50 and 100mv ....in some cases undervolting increases battery life and makes the phone cooler but not much ...

Under volting is when you tell the battery to provide a little less power than usual.
Which is why the battery life usually increases, as less battery is being used than previously.
But as stated, too much can cause the battery to not provide ENOUGH power, therefor crashes and cannot boot properly etc.

One-X-master said:
if too much undervolting the phone freezes/ reboot ....so the best value for undervolting is between 50 and 100mv ....in some cases undervolting increases battery life and makes the phone cooler but not much ...
Click to expand...
Click to collapse
Pretty much, I would say. Drastic increase of battery in games: phone won't get hot => battery will last longer without overheating and, what is much more important, it will stay healthier in long run.
Even on wall charger while playing, my HOX won't overheat with - 100mv UV.
This is the main feature I miss on JB Sense without custom kernels
Sent from my HTC One X using xda app-developers app

THANK YOU

MysteryE said:
Weird, I've tried this many times, and can't get the indicator show exactly 0 mA...
the lowest for me around 3-5 mA... :|
Click to expand...
Click to collapse
Same here. On both my old HTC Sensation, and my HOX. Never saw the mA reach 0. Even after leaving on the charger for a couple of days.

DarkManHaze said:
Same here. On both my old HTC Sensation, and my HOX. Never saw the mA reach 0. Even after leaving on the charger for a couple of days.
Click to expand...
Click to collapse
The problem is, the phone cannot get the same amount of energy, it consume (in fact, it is the millisecond, where the phone is fully charged, than it discharges for some minutes, than it will be charged again for three minutes and so on periodically). So, what I mean, you will almost never see 0 ma on one X or other modern phones. You can only see that, if device can disable battery while it is fully charge and use wall charger like a main supply. And the last device with such behavior was Huawei s7 back to 2010
So, 3-5ma is pretty ok.
Sent from my HTC One X using xda app-developers app

[Q] Best time to charge battery?

Actually when is the best time to charge the phone battery?
1) Less than 50%?
2) Less than 25%?
3) First warning at 14%?
4) Second warning at 4%?
5) Last warning at 1%?
6) Completely finish it?

Actually there is no definite need for a "best time" to charge.
Lithium batteries are best kept in charged state. Draining it to 0% won't do you any good neither.
My policy charging is to charge when its above 30%.
Because it in an extremely slight way harms the lithium-ions when it goes down to 0%.
Which is why all battery calibrating guides discourages frequent calibrating.
Low battery does not damage the device or the battery but it does create more radiation than usual.
Which is bad for human organs. That's the down side to low battery.
Last but not least, it is better to keep your phone charged than emptied at all times. Right?
Press thanks if you think I'm helpful. Thankyou.

Best is to recharge it when it's more than half full, because it won't have to endure heat for too long.
Heat is the #1 enemy for Li-ion batteries.
-- Sent from a GT-I8150 running ICS perfectly well. F'U, Sams#!t --

Thanks for your both advices. I always used until battery low warning appear. Is it good if I charge & play at the same time? And how long before unplug the charger after fully charged?

You're welcome.
Its not recommended though, your battery heats up extremely quickly if you charge while you play.(watching SD quality video is okay though, since the cpu isn't stressed to provide smoothness)
I do that once in awhile but once the temperature struck 40celcius I quit playing. (you'll notice, it gets hot real quick...)
You can download a battery status app to check its temperature.
Basically once its full its okay to unplug. Overcharging is extremely bad.

KiD3991 said:
You're welcome.
Its not recommended though, your battery heats up extremely quickly if you charge while you play.(watching SD quality video is okay though, since the cpu isn't stressed to provide smoothness)
I do that once in awhile but once the temperature struck 40celcius I quit playing. (you'll notice, it gets hot real quick...)
You can download a battery status app to check its temperature.
Basically once its full its okay to unplug. Overcharging is extremely bad.
Click to expand...
Click to collapse
Which app do you recommend?

kai92 said:
Which app do you recommend?
Click to expand...
Click to collapse
Temp+CPU pro. I'm using this. Its a widget app.
It shows you Cpu freq, Temp and free ram. Quite handy

kai92 said:
Which app do you recommend?
Click to expand...
Click to collapse
I use CPU Tuner; it not only regulates CPUfreq (and able to do an emergency cap on MaxFreq if the battery is hotter than a certain temperature), but it also provides widgets that can -- among others -- display the current temperature of the battery.

kai92 said:
Actually when is the best time to charge the phone battery?
1) Less than 50%?
2) Less than 25%?
3) First warning at 14%?
4) Second warning at 4%?
5) Last warning at 1%?
6) Completely finish it?
Click to expand...
Click to collapse
Have a read of these articles for some good tips and more advice on looking after Li-ion batteries.
http://www.techrepublic.com/blog/helpdesk/the-care-and-feeding-of-li-ion-batteries/124
http://www.gamersnexus.net/guides/899-battery-myths-li-ion-battery-management