this was posted on the XDA Portal on JANUARY 14, 2012 AT 7:38 AM BY Liwen..
and i thought i would repost it as it seems lately alot of people are being misinformed about it
Google Engineer Debunks Myth: Wiping Battery Stats Does Not Improve Battery Life...
There you have it, in the title. Google engineer Dianne Hackborn, who has previously explained Android’s hardware acceleration, took to Google+ again to clarify some myths about the Android operating system. This time, it’s a point of common advice that you’ll see in virtually every FAQ thread about custom ROMs and flashing: wiping battery stats in order to improve battery life.
The reasoning behind that piece of advice was something like this: If you, at some point, did not charge your Android device fully (for example, only to 80%), it would supposedly remember that battery level as “fully charged” – in this case, you’d only ever get to use 80% of your battery, which is of course less than optimal. So, if you wipe the battery stats, usually done in ClockWord Mod Recovery, the device would “forget” the previous level, here 80%, and instead charge to the full 100% once again, thereby re-calibrating the battery. Or, as Hackborn puts it in more technical terms:
The battery indicator in the status/notification bar is a reflection of the batterystats.bin file in the data/system/ directory.
However, as she explains, that’s not the case. Because those battery stats, stored in the batterystats.bin file, are only used to maintain information about what is using the battery when not recharging. That is, it essentially holds the information displayed in the Settings > Battery screen. Nothing more, nothing less. Thus:
It has no impact on the current battery level shown to you.
It has no impact on your battery life.
What’s more, you’ve probably noticed that the battery usage data is reset once you recharge your device anyway. From this you can correctly deduce that the battery stats are wiped as well – every time your device is recharged. More or less every day. If there was any effect, you would’ve noticed it without going into recovery and doing that stuff. Typical placebo, eh?
link to XDA Portal post
http://www.xda-developers.com/androi...-battery-life/
Where I got this ?
go to this thread http://forum.xda-developers.com/showthread.php?t=2170039
If this helped you, press the "Thanks" button for Kameirus on the second link, not me .
also Kameirus permitted me to post this on our forums as well
page not found
Good :good: OP of this thread is the only one here who has given credits from where he got the content!
Asmy Yuh said:
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I think they removed it already, but if this helped you, Give your thanks button to Kameirus. not me.
Related
Today's myth debunking:
"The battery indicator in the status/notification bar is a reflection of the batterystats.bin file in the data/system/ directory."
No, it does not.
This file is used to maintain, across reboots, low-level data about the kinds of operations the device and your apps are doing between battery changes. That is, it is solely used to compute the blame for battery usage shown in the "Battery Use" UI in settings.
That is, it has deeply significant things like "app X held a wake lock for 2 minutes" and "the screen was on at 60% brightness for 10 minutes."
It has no impact on the current battery level shown to you.
It has no impact on your battery life.
Deleting it is not going to do anything to make your more device more fantastic and wonderful... well, unless you have some deep hatred for seeing anything shown in the battery usage UI. And anyway, it is reset every time you unplug from power with a relatively full charge (thus why the battery usage UI data resets at that point), so this would be a much easier way to make it go away.
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https://plus.google.com/u/0/105051985738280261832/posts/FV3LVtdVxPT
Already threads on this..
Sent from my Galaxy Nexus using xda premium
i've known this for like 2 years. wiping batterystats.bin does nothing whatsoever. i just never have the energy to post it around the forum since you see so many people saying to wipe batt stats.
i tried to open the stats file one time and all it looked like to me was the same info you see in the battery settings menu with the list of apps used on battery, and wakelocks etc.
glad this is finally getting out there!
I also suspected this was the case but as I got what I expected from my battery I never really looked in to it although I have read the nonsense calibration posts etc.
Thanks for posting mate its confirmed my thoughts!
REGARDING BATTERY STATS!
http://www.androidcentral.com/wiping-battery-stats-doesnt-improve-battery-life-says-google-engineer
*THIS IS INFORMATION THAT I CAME ACROSS FOR ANYONE WONDERING ABOUT BATTERY LIFE AND STATS.
Excellent article. I've had my suspicions for a while -- having tried every method for "calibrating" my battery.
Want better battery life? Get a better ROM and keep tabs on your services.
ive never thought the CWM wipe battery stats would actually give me a longer battery life. i thought or just assumed it was to make sure the full charge, draining, and dead path of the battery % or whatever u call it would acurately flow with the new ROM i flashed.
Check this
For people that wipe battery stats after installing a new rom.
Regardless of the make and model of your Android-powered smartphone, you most definitely were advised at one point in your life to delete the "batterystats.bin" file, aka wipe your battery stats. That is, of course, if you are the techy user.
According to those who tell you that, deleting that certain file (possible via Recovery) will make the phone forget the previous charging level, allowing you to "recalibrate the battery". According to Dianne Hackborn, Android Framework Engineer, this is just a myth.
Those in favor of "wiping battery stats" say that the file referred to above will hold information about charging levels. The discussion usually pops up in scenarios in which battery lasts shorter than usual or a full charge is reported when the battery is practically not 100%. Believers say that if your phone reports a full charge at a real 92% for instance, deleting that "batterystats.bin" will get you back on track.
The Android Framework Engineer says that the following statement is false: "The battery indicator in the status/notification bar is a reflection of the batterystats.bin file in the data/system/ directory". According to Hackborn, the file usually holds the information related to which programs and processes use the battery between charges (hence being responsible for the OS' Battery Usage report screen).
Deleting this file will basically wipe your battery usage reports, which is done anyways automatically when the phone is fully charged (hence you'll see a clear list when you reach a full charge). "Deleting it is not going to do anything to make your more device more fantastic and wonderful".
Source:
http://pocketnow.com/android/deleting-androids-batterystatsbin-wont-grant-more-jiuce
Interesting. I've ordered a new battery and actually planned to do all of this 'battery calibration' stuff when I got it, but well, now I know different. Thanks.
Information on prolonging the life of Li-Ion batteries and way more about batteries in general...
---------- Post added at 05:03 PM ---------- Previous post was at 05:01 PM ----------
Tuoni said:
Interesting. I've ordered a new battery and actually planned to do all of this 'battery calibration' stuff when I got it, but well, now I know different. Thanks.
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Conditioning and caring for your battery still applies.
My Desire HD always shows battery to be well above 3600mV when the battery meter is at 1%..0%.
When fully charged, the battery is at 4211mV.
Is this normal?
I read from the Nexxus One "[UTILITY] Battery calibration tools" thread that the battery should go down to 3201mV to be at 0%. 3600mV to 3201mV is a quite wide range, so I'm wondering if a large portion of the battery capacity is wasted and not used.
I have tried various calibration methods, but it's still the same.
The "[UTILITY] Battery calibration tools" downloaded from Market does not work on my DHD. The tool is for batteries with the ds2784 chip, but my DHD is showing it has a ds2746 chip--from the driver directory.
I have tried to let the battery reach 0% and have a forced shutdown, and after that, I boot into recovery and let it stand for more than 10 minutes. And then after a reboot, the battery would be at below 3400mV. I could repeat the same procedure again, but I was afraid of deep discharging the battery to below 3201mV and damaging it.
Is there any way to calibrate the battery so that it's below 3300mV when the battery meter shows 1%?
Thanks.
Hi, i need more informations...is your phone rooted? Have you already tried wiping battery stats?
Do you have original or aftermarket battery?
Sent from my Desire HD using XDA App
Yes, the phone is perm rooted and Eng S-off.
When I tried various calibration methods, I tried to wipe battery stats when the battery reached 0% and also did a battery wipe when it's charged to 100%. I've also tried to just wipe the battery stats on a full charge but not when 0% left, but it doesn't make any differences.
The battery is an HTC original stock.
Phone was bought new last May, but I mainly used it as a mobile phone sparingly since last July (only a few days a month). I only started to use it seriously as a smart phone two months ago. I have a Leedroid-derived ROM on it, which is VERY power-conserving: averaging 1ma on stand-by.
_andrea_ said:
Hi, i need more informations...is your phone rooted? Have you already tried wiping battery stats?
Do you have original or aftermarket battery?
Sent from my Desire HD using XDA App
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+1
+1.
Having same issue. last night my battery died at 3680mv. after completely shut down. I remove battery & leave for 20mins.
When i reconnect battery & power up. jumps back to 2% battery. & dies again after further 10mins still over 3600mv.
Can repeat this several times.
but never gets below 3600mv.
Have tried same as stated above. wiping batt stats when 0% & 100%.
I have..
DHD RCmix3D 2.3.5 sense 3.5. Lordmod v5.0 kernel. Original battery.
PUSH
No one has an answer?
My thoughts exactly. Think you might need a sensation etc to get any support these days.
Havnt been a member long. So far have had little help & see plenty of arguing :S
Sent from my Desire HD using XDA App
I'm facing the same issue.
My phone shuts off approximately 3650mv.
I have tried both android reveluton and leedroid roms. Both are the same.
Cannot get a full day battery power. Please help
I started this thread here in the DHD Q&A forum simply because I was not allowed to post on those battery-related threads in the development forums, since I was new here. Those development forums are where the experts are, and I wasn't expecting to get a real answer here an way. I'm collecting my 10th post on xda, and so it's time to move this question to where it should really belong. I'll post an update here if any expert speaks.
hchao said:
I started this thread here in the DHD Q&A forum simply because I was not allowed to post on those battery-related threads in the development forums, since I was new here. Those development forums are where the experts are, and I wasn't expecting to get a real answer here an way. I'm collecting my 10th post on xda, and so it's time to move this question to where it should really belong. I'll post an update here if any expert speaks.
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Thanks!
Hopefully somebody helps to solve our problem.
It is very annoying that the phone shuts down itself while there is so much power stays in it...
I see that my desire hd uses 3-5mA in standby, but when the screen is on it jumps to the 300mA that is very high.
I have done all recomended steps in forum (like auto sync, live wallpaper, etc.) but the problem hasn't solved
My DHD battery lasted 3days and 4 hours.
Still left 10% 3628mV in medium usage and max 100% 4206mV. DHD battery maybe not go to below than 3580 - 3630mV. It depends on battery, hardware, software and usage on device.
and
sorry for my english is not so good.
maybe you didn't perform a total wipe
try to wipe all:
- data and cache
- Dalvik cache
that should reset the battery information
good lauck
I am sure that I have wiped it all.
Looking for technical answer. Why several charge cycles for ROM to "settle in"?
So we all know its a common rule when we flash a new ROM we should give it 2 or 3 full charge cycles to "settle in" before we judge what our battery life will be.
But why?
I did Google it, and really only came up with the conclusion that its common knowledge. "Because thats the way it is". But can someone give a white paper type of reply?
No one can, because it's not true.
It's along the lines of clearing battery stats or calibrating the battery. A Google engineer made a public post that it's all cargo cult nonsense, and that all that's contained in the battery stats is info for generating those pretty graphs in the settings screen, but people around here persist in continuing to do so.
Yeah, it's bull****.
Sent from my SGH-T989 using Tapatalk
More or less the few min on boot thing, is its booting, allows the rom to fully initiate on its own, not 100% needed but does help in the sense that like windows if u open crap while its still booting it can tend to throw the system off a lil bit.
Few batterycycles, bull****.
Clear batterystats?some devices it CAN help, with this phone its pointless, as this phone has a chip to automaticly calibrate the battery anyways.
All these "tips" are more or less worthless to us and can be taken lightly..
Cool thanks guys
edit: manekineko...I search a little but couldnt find it. Can you give me some search terms or a link (if you can find it quickly) to that Google engineer's comments?
blackangst said:
Cool thanks guys
edit: manekineko...I search a little but couldnt find it. Can you give me some search terms or a link (if you can find it quickly) to that Google engineer's comments?
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Here it is...
https://plus.google.com/u/0/105051985738280261832/posts/FV3LVtdVxPT
and an article that links to the google + above...
http://www.talkandroid.com/83611-go...ats-doesnt-improve-battery-life/#.T2dqChEgelg
G1ForFun said:
Here it is...
https://plus.google.com/u/0/105051985738280261832/posts/FV3LVtdVxPT
and an article that links to the google + above...
http://www.talkandroid.com/83611-go...ats-doesnt-improve-battery-life/#.T2dqChEgelg
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Thanks! Sig worthy!
now can someone explain why sometimes it takes a long time to drop batt% when it is high but quickly drops when it's in the reds... or the opposite that it drops really quick when its high but lasts forever when it's red
or when you restart your phone.. your battery level sometimes jump or drops drastically
my guess is that sometimes that chip that automatically calibrates and reads your battery is sometime inaccurate after you poweroff/reboot/pull battery.
Just a guess, but I don't really care much about all that nonsense because our phone lasts a damn long time!
Teo032 said:
now can someone explain why sometimes it takes a long time to drop batt% when it is high but quickly drops when it's in the reds... or the opposite that it drops really quick when its high but lasts forever when it's red
or when you restart your phone.. your battery level sometimes jump or drops drastically
my guess is that sometimes that chip that automatically calibrates and reads your battery is sometime inaccurate after you poweroff/reboot/pull battery.
Just a guess, but I don't really care much about all that nonsense because our phone lasts a damn long time!
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Your battery % is read from the mah left inside the battery, these readings are then translated by the OS into a percsnt based of the max mah on the battery.
Once the percentage is obtained/displayed a new cycle begins, battery drain is completely depentant on the use of the device.
That being said on reboots the first known "cycle" as il refer to it as, is displayed. This first response is usually correct but can vary slightly until the system crosschecks the data.
If that does happen, wit a minute and the system will correct the value in approximately a minute.. hopefully thats clear enough and hope it answeres your question..
Thought i hit post but didnt n left browser open all mornin :/ lmao
doug36 said:
Your battery % is read from the mah left inside the battery, these readings are then translated by the OS into a percsnt based of the max mah on the battery.
Once the percentage is obtained/displayed a new cycle begins, battery drain is completely depentant on the use of the device.
That being said on reboots the first known "cycle" as il refer to it as, is displayed. This first response is usually correct but can vary slightly until the system crosschecks the data.
If that does happen, wit a minute and the system will correct the value in approximately a minute.. hopefully thats clear enough and hope it answeres your question..
Thought i hit post but didnt n left browser open all mornin :/ lmao
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I have yet to see the system suddenly correct the value. And no i was referring to battery drain with the same usage. They drain differently, it is never a linear drain. And i believe it's more than just measuring the mah left in the battery because a dead battery still has mah. And then there are extended batteries with higher mah. Oh wells.
Sent from my SGH-T989 using xda premium
Teo032 said:
I have yet to see the system suddenly correct the value. And no i was referring to battery drain with the same usage. They drain differently, it is never a linear drain. And i believe it's more than just measuring the mah left in the battery because a dead battery still has mah. And then there are extended batteries with higher mah. Oh wells.
Sent from my SGH-T989 using xda premium
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No crap, there higher capacity/higher MAH
And No Li-iON battery will die down to 0 MAH...
*edit
And seeing as you obviously don't know how to use google, I saved you the trouble
Terminology: mAh
Definition: The mAh acronym stands for Ampere-hour.
This is a unit of electric charge, and is frequently used in measurements of electrochemical systems such as batteries.
Example: a 2000mAh cell is half the charge capacity of a 4000mAh
If you can't take the answer given, don't ask.
Ofc its not a liniar drain ita based off usage/aps running..
And yes this is called for
Info on batterys
http://www.knowyourmobile.com/glossary/m/513466/mah.html
*EDIT2
Found a plausible way for you to achieve that close to linear drain you so desire:
A.) Install stock rom & kernel,
B.) Root, remove all bloat and ALL apps, as some start automaticly and and are registered as services and last through taskkillers.
C.) Disable ALL sync features, turn on airplane mode.
D.) don't touch phone for a few days..
Should be pretty damn linear for ye