Database Info

Why is Android's battery always so darn inaccurate

My icon in the notif bar looks like 80% and it is 40% lol. I don't get it.

hah2110 said:
My icon in the notif bar looks like 80% and it is 40% lol. I don't get it.
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Strange, I haven't noticed this.
1) What phone are you using
2) What ROM are you running
3) Have you wiped your phone along with the cache?

akapoor said:
Strange, I haven't noticed this.
1) What phone are you using
2) What ROM are you running
3) Have you wiped your phone along with the cache?
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Click to collapse
Almost every Android phone. It is a known problem.

I don't seem to have an issue with it.
When it reaches 75%, my bar is 3/4s. When it's 50, its half-way...etc...etc...

hah2110 said:
Almost every Android phone. It is a known problem.
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Click to collapse
Awsome job answering 3 questions with a random statement.
I know the phone stores the info about the battery in a file. This file includes the max charge the battery can charge too. There is a method somewhere on these forums that show how to drain your battery, wipe the file, then do a full charge so the phone can relearn the battery and the correct settings get saved.
I believe flashing new roms and doing storage wipes can cause this file to be removed and created with false info.

WoZeR said:
Awsome job answering 3 questions with a random statement.
I know the phone stores the info about the battery in a file. This file includes the max charge the battery can charge too. There is a method somewhere on these forums that show how to drain your battery, wipe the file, then do a full charge so the phone can relearn the battery and the correct settings get saved.
I believe flashing new roms and doing storage wipes can cause this file to be removed and created with false info.
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Click to collapse
No... It has nothing to do with this. Every Android phone I've had... Regardless of whether it is brand new, stock, rooted, flashed, new kernel, anything... Doesn't matter.

May I know how many android phones you previously had?
not trying to flame btw.. but i dont have that case with my phone.. and this is my first phone

You have tokinda program the Lion Batt internal charger first, you charge them full->run till dead--> repeat process 2 times and then the system will be way more accurate. Try this and reply in about 3 days the results.

lagu805 said:
May I know how many android phones you previously had?
not trying to flame btw.. but i dont have that case with my phone.. and this is my first phone
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John512 said:
You have tokinda program the Lion Batt internal charger first, you charge them full->run till dead--> repeat process 2 times and then the system will be way more accurate. Try this and reply in about 3 days the results.
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Click to collapse
You guys are still missing it. The ICON is not accurate but the internal sensor is. Jeebus. Look at these links... and it seems as my answer is in the first two sentences:
http://senk9.wordpress.com/2010/06/07/android-app-of-the-day-battery-left-widget/
http://www.androidjunkies.com/index...ets-you-keep-watch-of-your-power-app-reviews/

Honestly, if "it" truly bothers you, why not just put the overlay ontop so you get the "real" percentage.

It's work just fine for me, usually +/- 3% at most, works great on froyo.
Calibrate if it is way off
Sent from my HTC Magic using XDA App

I'm trying to understand how android calculates battery percentage, and from my testing it seems that the battery meter is hard coded into each particular phone model. This link seems to kinda verify this.
http://www.android-x86.org/documents/howtoconfigurebatteryservice
Does anyone know where in the system the battery file is located? Either the battery driver, or the algorithm it uses, or even a stats file. Anyone able to point me in the right direction? Thanks.

Daveenna said:
It's work just fine for me, usually +/- 3% at most, works great on froyo.
Calibrate if it is way off
Sent from my HTC Magic using XDA App
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How abouts do you calibrate the visual battery indicator at the top of the notification bar to be within 3%??
Are you talking about something else like the battery charge status reading?
I've experienced the same problem as the OP on all my Android phones as well. It is a problem when you think you have 75% charge and all the sudden you are getting low battery warnings.

same here. Notification Bar battery is hilariously off.

akapoor said:
I don't seem to have an issue with it.
When it reaches 75%, my bar is 3/4s. When it's 50, its half-way...etc...etc...
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oh yea? mine goes to nine percent...and takes forever for it to shut down. only when i shut down the phone or reboot it, does it not come back on. lol

Battery Life Record

Moderate Use
Doctorz V8
Stock kernel
No voltage changes or clocking aside from what comes with the RoM.
Auto screen brightness.
Main difference is Background Data is off for everything but Market.
Sent from my SGH-I997 using Tapatalk

What do you mean by background data and how do you set that?
Sent from my SGH-I997 using XDA App

Just an observation, but the graph at the top under where it says 1 day 19 hours clearly shows your battery going up 3 times. Which I was just going to pass up but I have a bunch of shots of my battery stats and none of them go up.
[IMG]http://i1111.photobucket.com/albums/h472/BadFishCM/SC20110821-130202.png[/IMG]
So if I'm not mistaken you plugged in a couple times.

I seen that as well but I honestly have no idea why. I can assure you it has not been plugged in. I even have a prior screen shot on another battery run that has the same issue.
Sent from my SGH-I997 using Tapatalk

Thats impossible, theirs no way for a phone to charge itself while discharging. Something is screwed up with your battery calibration.
Sent from my SAMSUNG-SGH-I997 using xda premium

Battery Management
Hi, all.
I want to pass this tip along to anyone who want or need to conserve their battery for what ever reasons.
I have gone usually 3 day+ on one charge.
I'm running on stock rom. Froyo 2.2.1
It is rooted though
I use the phone moderately. Text occasionally.
I downloaded an app called "DataSwitch" by TomatoX.
I use wifi when I'm at home or work.
I have dataswitch activated when I don't need constant background data. ?I turn it on when I need to use it for surfing and such.
In Settings, there is also a toggle for background on/off, although I don't use this much.
With the data off, you can still get phone call and text msg.
I usually turn off data and wifi at bedtime.
On the third day, I'm usually down to 35%.
This may also be useful if you are low and can't get to a charge right away.
It may not apply to everybody, but it works for me..esp with only a 200mb data plan. Battery life is great!

lol look at that cell standby use your phone lol

xKrisx said:
Moderate Use
Doctorz V8
Stock kernel
No voltage changes or clocking aside from what comes with the RoM.
Auto screen brightness.
Main difference is Background Data is off for everything but Market.
Sent from my SGH-I997 using Tapatalk
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Click to collapse
Good one. But next time on, it would be more useful if you post the screenshots showing call duration and display time. With just this one screenshot it could have display on for just 5 mins or 50 mins. Its hard to tell.
Just now noticed, the tiny green bars in the screenshot (circled in red) come up when the phone is charging.

I noticed that (at least for my phone) if you connect it to wall charging it would reset the "time on battery" count but if i connected it via usb to pc it was charging, yeah slowly maybe but the timer never reset when connected via usb as if the phone said "well im charging but it doesnt counts since the guy its transfering data"(lmao yeah my phone is smart) so if you wait for 10% battery ans then go usb mode and charge it and use it and repeat i once got displaying 4 days 10 hours on battery haha.
While on my real stats my phone never last more than 18 hours ;/
Sent from my SAMSUNG-SGH-I997 using XDA App

koriotto said:
I noticed that (at least for my phone) if you connect it to wall charging it would reset the "time on battery" count but if i connected it via usb to pc it was charging, yeah slowly maybe but the timer never reset when connected via usb as if the phone said "well im charging but it doesnt counts since the guy its transfering data"(lmao yeah my phone is smart) so if you wait for 10% battery ans then go usb mode and charge it and use it and repeat i once got displaying 4 days 10 hours on battery haha.
While on my real stats my phone never last more than 18 hours ;/
Sent from my SAMSUNG-SGH-I997 using XDA App
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+ 1
I got my phone to say 2 days 15 hours once. As long as I don't charge it 100% the time on my battery continues to go up. I can plug it in while it has 10% left charge it till its 90% unplug it, and the time won't reset.

If anyone mistook my comment, I'm not really interested in claiming any specific record as the op as stated.
I simply meant to share my thoughts on "dataswitch" app and how I had applied it.
I think found it useful to limit data usage and to conserve the battery when I can't get a charge right away.
You'll be surprise how much battery life background data consumes.
The other part tech part of me also recognizes that battery memory exist...it may be best to "widen" your charge range (0% to 100%) when possible.

Well, I figured out what caused that.. My radio in my truck has a USB port that I plug my phone into to listen to my music. Worked great on my Ipod but it wouldn't charge my Ipod. However today when coming home, I plugged my phone in and it doesnt show to be charging, but when I looked at the Battery Use chart, it deffinately showed an increase.
And here I was thinking I was getting impecable battery life lol.
Oh well.. Sorry for the fuss. However, I will keep trying

xKrisx said:
Well, I figured out what caused that.. My radio in my truck has a USB port that I plug my phone into to listen to my music. Worked great on my Ipod but it wouldn't charge my Ipod. However today when coming home, I plugged my phone in and it doesnt show to be charging, but when I looked at the Battery Use chart, it deffinately showed an increase.
And here I was thinking I was getting impecable battery life lol.
Oh well.. Sorry for the fuss. However, I will keep trying
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There you go. Mystery solved. Case closed.

more like....busted?

alc630 said:
more like....busted?
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Can't use a hard word. Looks like he is still new and didn't realize his phone was charging. Well, he didn't realize that the green line in pic meant charging. So he gets benefit of doubt.

stock Froyo...
one charge...for real
lol..light use.

qkster said:
stock Froyo...
one charge...for real
lol..light use.
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Good one. Capture the display time and call time too please next time on.

qkster said:
stock Froyo...
one charge...for real
lol..light use.
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Click to collapse
And I'm a kung fu panda.

diablo009 said:
Good one. Capture the display time and call time too please next time on.
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How do I do that?
I tried going into settings, about phone, and battery use. That was the img I got.
I'm not sure how to bring up the charge graph, display time and call time as well...
On stock froyo 2.2.1. Baseband I997UCKH1. Kernel 2.6.32.9
I can try it again in a few days if you can tell me how
I'm also using screenshot from the Market.
I'm new at this so tell me step by step pls.
thnks

qkster said:
How do I do that?
I tried going into settings, about phone, and battery use. That was the img I got.
I'm not sure how to bring up the charge graph, display time and call time as well...
On stock froyo 2.2.1. Baseband I997UCKH1. Kernel 2.6.32.9
I can try it again in a few days if you can tell me how
I'm also using screenshot from the Market.
I'm new at this so tell me step by step pls.
thnks
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Click on individual elements listed to show more details about them.

[Q] Strange battery issue

Note: I searched the forum and saw nothing like my issue, if there is then I missed it and I apologize.
So here is the issue. When charging it gets to between 85-90% then immediately jumps to 100%. Have tried clearing the stats, draining, then full charge. Any suggestions on this?

How old is the battery are you charging USB or AC?
Most likely its a old battery
Sent from my Inspire 4G using xda premium

virusmonk3y said:
Note: I searched the forum and saw nothing like my issue, if there is then I missed it and I apologize.
So here is the issue. When charging it gets to between 85-90% then immediately jumps to 100%. Have tried clearing the stats, draining, then full charge. Any suggestions on this?
Click to expand...
Click to collapse
very odd, I've actually experienced the inverse. Charge would hold at like 20% and then jump to 10% in a second. Are you noticing in use there is a jump back down i.e. when you unplug, does it jump from 100% straight to 90% or does this just happen when charging. If it just happens with charging, I'd say run current widget and see how much mA is left when it makes the jump to 100% and see if the battery is actually charging correctly. In other words, if you're charging and the battery jumps from 90 to 100 and you still have like 200 mA left, something is goofy with your battery and I'd recommend a new battery or at the very least full wiping and reflashing your ROM.
If it jumps and the remaining mA is like 30 or something low, then the actual battery seems to be fine and I'd recommend a full wipe and reflash the rom you're using. In all honestly, it's probably the battery and may just be worth getting a new one.

virusmonk3y said:
Note: I searched the forum and saw nothing like my issue, if there is then I missed it and I apologize.
So here is the issue. When charging it gets to between 85-90% then immediately jumps to 100%. Have tried clearing the stats, draining, then full charge. Any suggestions on this?
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Click to collapse
Im not attacking you im just trying to clarify. Are you saying it jumps to 100%, meaning you see it say 100% or are you referring to the led going green at about 90%?

I'm not convinced it is a battery issue... I've only very recently rooted my phone (have had it for 11 months) and haven't had the charge indicator jump past the last 10% like it did just today.
Looking at the last 26hours of history (ICS 3.0.0 install), the initial battery discharge showed normal taper from 100-85%, however on charge it jumped from somewhere just below 90% to 100% instantaneously.
I should have taken a screenshot, but instead I wiped the battery stats and am in the initial discharge cycle still. I've had the phone 11 months and have never cleared the battery stats before.

Maybe 8 months old.
Sent from the internets

Darunion said:
Im not attacking you im just trying to clarify. Are you saying it jumps to 100%, meaning you see it say 100% or are you referring to the led going green at about 90%?
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Click to collapse
When it hits 85-90% the led turns green then it shows 100% right after that.
Sent from the internets

virusmonk3y said:
When it hits 85-90% the led turns green then it shows 100% right after that.
Sent from the internets
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the led is supposed to go green at 90% to indicate trickle charge mode. but ya that should not be triggering the 100%. are you using a battery mod that isnt included with the rom?

virusmonk3y said:
When it hits 85-90% the led turns green then it shows 100% right after that.
Sent from the internets
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Click to collapse
Run the battery down until the phone dies. I have had this happen to me before. When I got down to 1%, it took a really long time for the phone to die. Recharging and doing a couple of long cycles of letting the battery go down to a really low level before charging fixed it. Do not delete battery stats as it does no good.
Sent from my Inspire 4G using Tapatalk

fernandezhjr said:
Run the battery down until the phone dies. I have had this happen to me before. When I got down to 1%, it took a really long time for the phone to die. Recharging and doing a couple of long cycles of letting the battery go down to a really low level before charging fixed it. Do not delete battery stats as it does no good.
Sent from my Inspire 4G using Tapatalk
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Click to collapse
Did that already, stated that in OP
Sent from the internets

Darunion said:
the led is supposed to go green at 90% to indicate trickle charge mode. but ya that should not be triggering the 100%. are you using a battery mod that isnt included with the rom?
Click to expand...
Click to collapse
No mod on the battery.
Sent from the internets

virusmonk3y said:
Did that already, stated that in OP
Sent from the internets
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You stated in the op you cleared battery stats. I specifically mentioned trying the process without clearing battery stats and doing some additional cycles without clearing.
Sent from my Inspire 4G using Tapatalk

fernandezhjr said:
You stated in the op you cleared battery stats. I specifically mentioned trying the process without clearing battery stats and doing some additional cycles without clearing.
Sent from my Inspire 4G using Tapatalk
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Indeed. I did that twice actually
Sent from the internets

virusmonk3y said:
Indeed. I did that twice actually
Sent from the internets
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Well if calibration processes fail to correct it, then I would suspect a bad battery.
Sent from my Inspire 4G using Tapatalk

You might try an app called Battery Calibration. Found here http://forum.xda-developers.com/showthread.php?t=1024867
I don't necessarily use it to calibrate but to monitor the mV. It might help in seeing if it is in fact a bad battery or if your battery indicator is showing a false reading.
Sent from my MB860 using Tapatalk

jp2132 said:
You might try an app called Battery Calibration. Found here http://forum.xda-developers.com/showthread.php?t=1024867
I don't necessarily use it to calibrate but to monitor the mV. It might help in seeing if it is in fact a bad battery or if your battery indicator is showing a false reading.
Sent from my MB860 using Tapatalk
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Yea I tried that after the normal calibration. Another weird thing is my phone has been sitting at 1% for like an hour.
Sent from the internets

virusmonk3y said:
Yea I tried that after the normal calibration. Another weird thing is my phone has been sitting at 1% for like an hour.
Sent from the internets
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Go back and read my first post. I told you this would happen.
Sent from my Inspire 4G using Tapatalk

fernandezhjr said:
Go back and read my first post. I told you this would happen.
Sent from my Inspire 4G using Tapatalk
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The sitting at 1% was happening before. Just never really payed attention to it. Have tried the normal calibration twice now and the method you mentioned as well. Going to ATT tomorrow and see about exchanging the battery. Will post results.
Edit: Want to add a thanks for all the suggestions from everyone.
Sent from the internets

virusmonk3y said:
The sitting at 1% was happening before. Just never really payed attention to it. Have tried the normal calibration twice now and the method you mentioned as well. Going to ATT tomorrow and see about exchanging the battery. Will post results.
Edit: Want to add a thanks for all the suggestions from everyone.
Sent from the internets
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Then it may be that time. I got my battery to hold out a little longer, but soon after, I started getting bad drain. I recently replaced my battery and haven't had issues since.
Sent from my Inspire 4G using Tapatalk

virusmonk3y said:
The sitting at 1% was happening before. Just never really payed attention to it. Have tried the normal calibration twice now and the method you mentioned as well. Going to ATT tomorrow and see about exchanging the battery. Will post results.
Edit: Want to add a thanks for all the suggestions from everyone.
Sent from the internets
Click to expand...
Click to collapse
Sounds more like a battery calibration issue than a battery issue.
Give it a bit of thought... from 90% it skips to 100% when charging. However at 1% it camps out for an hour or more before shutting off. This indicates an issue with how the charge of the battery is being measured/expressed...
Now let's think about what is happening behind the scenes. This measure of charge is "defined as the available capacity expressed as a percentage of some reference, sometimes its rated capacity but more likely its current (i.e. at the latest charge-discharge cycle) capacity but this ambiguity can lead to confusion and errors. It is not usually an absolute measure in Coulombs, kWh or Ah of the energy left in the battery which would be less confusing. "
Essentially, the way the phone is measuring the battery isn't working correctly. However, is the duration of the battery life what you would expect given your use of it?
If YES, then it's a measuring issue.

battery not showing correct capacity

So this is my issue, the battery percentage seems to fluctuate badly, there will be one instance where it will charge till 75% and then stop charging and it will say like 1 minute till full charge then never go beyond 75%.
Another instance is the battery will go down really quickly to 1% then it will operate on 1% for like upto 2 hours and then shut down finally.
Things I've done so far.
Changed rom clean flash, wiped caches, flashed stock in odin.
The only thing now is my bootloader is from an older firmware than the rom firmware currently installed which is cas rom.
Any insight or help would be great full. Thank you

Bump, does this sound like a hardware battery issue?

sofir786 said:
Bump, does this sound like a hardware battery issue?
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Click to collapse
Try a new cable?
Sent from my SM-G920W8 using Tapatalk

DarryDoo said:
Try a new cable?
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Click to collapse
I'll see if I can find another but this cable charges other devices fine

I have problems too with battery capacity especially at last 15% before i wasn't have this problem

It's very annoying because I never know how much battery I actually have left, I have to always have my portable charger with me just in case

sofir786 said:
It's very annoying because I never know how much battery I actually have left, I have to always have my portable charger with me just in case
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Click to collapse
I would simply first try another cable and also wall adaper. If this doesnt change anything, make a backup and go FULL stock. Not just flashing some oartitions, but your last stock ROM completely. If this doesn't make a change, then it probably is your battery, that is faulty. Try to have Samsung exchange it then. I just hope that we won't have similar problems, as the Note and S7 ppl.
Sent from my SM-G925F using XDA Free mobile app

Battery charging itself ?

Hellp guys I know it may sound crazy but here is what happened tk my S8+ .
1st timd it happened i left my phone with 51% shut it down..when i woke up it was 60.. but i thought whatever maybe my mind made this story up so i let it go.
Yesterday the same thing happened again i swear..i left my phone with 3% ..woke up today with 10.. what do u guys think its the problem?
I would appreciate if u help me
I must add , tbe battery life its still pretty great here .

albaniandroid said:
Hellp guys I know it may sound crazy but here is what happened tk my S8+ .
1st timd it happened i left my phone with 51% shut it down..when i woke up it was 60.. but i thought whatever maybe my mind made this story up so i let it go.
Yesterday the same thing happened again i swear..i left my phone with 3% ..woke up today with 10.. what do u guys think its the problem?
I would appreciate if u help me
I must add , tbe battery life its still pretty great here .
Click to expand...
Click to collapse
I'm not sure if it is dependent on battery type. But some battery types can regenerate little when stopped being used (switched off). It is chemical regeneration. Similar process happens when battery goes to 0. After some time it can power device again for few seconds. It do not repeat endlessly. Also the voltage drop that is taken (I assume) to calculation of the battery % is not straight line. It drops slowly when full and rapidly when near empty.
Sent from my SM-G955F using Tapatalk

jakub.wach said:
I'm not sure if it is dependent on battery type. But some battery types can regenerate little when stopped being used (switched off). It is chemical regeneration. Similar process happens when battery goes to 0. After some time it can power device again for few seconds. It do not repeat endlessly. Also the voltage drop that is taken (I assume) to calculation of the battery % is not straight line. It drops slowly when full and rapidly when near empty.
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Click to collapse
Do I need to get worried ?

albaniandroid said:
Do I need to get worried ?
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Click to collapse
No. Everything I described is natural also for new batteries.
Sent from my SM-G955F using Tapatalk

jakub.wach said:
No. Everything I described is natural also for new batteries.
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Click to collapse
Thanks man !