Database Users

Wiping battery stats doesn't improve battery life, says Google engineer

As posted on Android Central, a Google engineer has explained exactly what the batterystats.bin file contains:
"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."
https://plus.google.com/u/0/1050519...dVxPT#105051985738280261832/posts/FV3LVtdVxPT
http://www.androidcentral.com/wiping-battery-stats-doesnt-improve-battery-life-says-google-engineer

So whats the function for?
For us to imagine that i makes a difference?

This is just yet another Internet myth perpetuated by people, allowed to spread on forums and blogs.
It's been known for some time that the battery calibration is done by the power management chip, and the file plays no part.

DaddyCool08 said:
So whats the function for?
For us to imagine that i makes a difference?
Click to expand...
Click to collapse
The option is not from Google. CWM Recovery got it wrong it seems.
Sent from my GT-I9100 using xda premium

tietherope said:
The option is not from Google. CWM Recovery got it wrong it seems.
Sent from my GT-I9100 using xda premium
Click to expand...
Click to collapse
Of course i know that its not from G.
Maybe cwm team should take the option away then.

Diannes great to follow on G+. Shes after putting up some really good posts clearing up a few things

On some HTC devices, I believe battery stats are used to load heuristics into the fuel gauge chipset - but not on any Samsungs I am aware of. The fuel gauge on almost all Samsung devices is designed to not require calibration. (It is slightly less accurate and can get "faked out" in some corner cases, such as a reboot on low battery, for this reason - but it will also never go COMPLETELY wacky and will always converge towards truth.)
On some HTC devices, an improperly calibrated battery could cause a false low battery reading that would trigger an early shutdown - the battery wasn't really low but the device thought it was.
Note that the actual battery heuristics file on such devices might be something other than batterystats.bin - As I understand it, CM7 on the Nook Color had battery calibration issues for a while because it had a fuel gauge that DID require battery history info and the info was not being saved correctly.
However, I will say this again: Battery history is not, and cannot, be used in any way to affect the fuel gauge IC used in every Samsung device I have ever worked with.
http://www.maxim-ic.com/datasheet/index.mvp/id/6621 - Good read, that's the fuel gauge used by all first-gen Galaxy S phones. The MAX17042 used in the GSII is not publically documented, but it is similar - it has a few extra features which are not used in our device.

Wipe battery stats has always meant just that to me but many users interpret wiping stats as calibrating a battery .
So over time and from SGS1 days its been misused as wipe battery stats to recalibrate your phones battery .
I still wipe battery stats when i want to reset the readings .
jje

Deleting batterystats.bin just making a display of battery level correct.

I always knew it wont make a difference. Even when people RELIGIOUSLY "RECALIBRATE" the battery, its nothing more than killing the battery prematurely by such UNNECESSARILY DEEP DISCHARGE and CHARGE cycles! Max it can do is to reset the battery meter to hopefully display more accurate info temporarily.

Sergio_O said:
Deleting batterystats.bin just making a display of battery level correct.
Click to expand...
Click to collapse
No.
"It has no impact on the current battery level shown to you." from the OP

Wiping battery stats = Nothing.
Cycling battery = Win.

Wiping battery stats = Nothing
Wiping cache & dalvik cache = win win!

What is the proper way to calibrate the battery then?

Fwuffy86 said:
What is the proper way to calibrate the battery then?
Click to expand...
Click to collapse
Very simple you wipe battery stats if you have problems with the readings and even after flashing a new rom .
Battery calibration you put the battery in the phone and charge it you then use the phone .
This post tells you the battery calibrates itself .
jje

Sergio_O said:
Deleting batterystats.bin just making a display of battery level correct.
Click to expand...
Click to collapse
NO. The post linked to the OP is specifically saying that this is not the case.

Fwuffy86 said:
What is the proper way to calibrate the battery then?
Click to expand...
Click to collapse
Do nothing and wait - On Samsungs, rebooting the device on low battery (<50% or so) can cause it to falsely report low - it will converge towards truth (with the SoC estimate actually increasing over time) over the course of a few hours.

It definitely made a huge difference on my HTC Magic years ago, this was no placebo effect, however, I've never reset battery stats on either the SGS or S2 so can't comment.

tietherope said:
As posted on Android Central, a Google engineer has explained exactly what the batterystats.bin file contains:
"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."
Click to expand...
Click to collapse
maybe , but all the time that i wiped my battery it had positive effect on my battery drain !!!!!

Battery Calibration?

I am kind of amazed with what I am seeing, and am wondering if someone on XDA can help me understand this. So I was running CM7.x on my MT4G for over an year, and this past weekend I switched to CoreDroid because I wanted to try out Sense.
I had a bad feeling about the battery usage because the ROM was "heavier" than CM7.x in terms of UI, Graphics (of course because of Sense 3.5). I went ahead and installed the ROM anyways.
Within a couple of hours, I went from being fully charged to 5% battery....it was draining faster than anything I have seen before. I read CoreDroid release notes and they had mentioned about this severely fast battery drain.
Based on their recommendation, I fully charged the phone once battery level reached 5%. This time, my battery lasted about 17-18 hours, and again I fully charged it when it reached 5%.
Now after the second recharge, its been about 24 hours and I am at 97% battery. I didn't believe CoreDroid release notes that battery life will become better after couple of recharges; I thought it was a bunch of bull to get people to install their ROM.
I am glad to say I was wrong Can someone please explain this battery calibration deal to me?

Oh boy... This is a highly controversial topic. Here we go.
Basically there are people who swear by it and people who say it does nothing. That its all in your head.
Even this lady at google who helped create Android says it does nothing.
https://plus.google.com/105051985738280261832/posts/FV3LVtdVxPT
Sent from my HTC Glacier using XDA App

estallings15 said:
Oh boy... This is a highly controversial topic. Here we go.
Basically there are people who swear by it and people who say it does nothing. That its all in your head.
Even this lady at google who helped create Android says it does nothing.
https://plus.google.com/105051985738280261832/posts/FV3LVtdVxPT
Sent from my HTC Glacier using XDA App
Click to expand...
Click to collapse
Best link ever; most informative.
- I think everyone loves Dianne now.
- Someone has a flying car already ...
- In the middle of the most intellectual and technical discussion of battery usage that I have seen, someone asks what is the best facebook app - brilliant!
So...
1. Battery stats are calculated differently per phone and OS version.
2. Battery stats reporting is definitely not %100 accurate.
3. Battery percentage is calculated differently per phone and OS version.
4. Battery percentage reporting is definitely not %100 accurate.
5. On some phones, you can override battery charging limitations by 'bumping'.
6. 'Bumping' is not recommended as can shorten your battery life.
They actually did not cover the OP situation where you let that battery go below 5%, although I am always guilty of skim reading. Still, extremely informative and explains a lot of previously posted battery phenomena.

estallings15 said:
Oh boy... This is a highly controversial topic. Here we go.
Basically there are people who swear by it and people who say it does nothing. That its all in your head.
Even this lady at google who helped create Android says it does nothing.
Sent from my HTC Glacier using XDA App
Click to expand...
Click to collapse
Wow, that made up for intense reading - thanks a lot.
It can't be something in my head for sure, If the difference was say a couple of hours I probably would have agreed with "the lady at Google" But I went from 2-3 hours to 24+ hours, so yes it's not in my head
Thanks again for your feedback.

Homerbsharp said:
Best link ever; most informative.
- I think everyone loves Dianne now.
- Someone has a flying car already ...
- In the middle of the most intellectual and technical discussion of battery usage that I have seen, someone asks what is the best facebook app - brilliant!
So...
1. Battery stats are calculated differently per phone and OS version.
2. Battery stats reporting is definitely not %100 accurate.
3. Battery percentage is calculated differently per phone and OS version.
4. Battery percentage reporting is definitely not %100 accurate.
5. On some phones, you can override battery charging limitations by 'bumping'.
6. 'Bumping' is not recommended as can shorten your battery life.
They actually did not cover the OP situation where you let that battery go below 5%, although I am always guilty of skim reading. Still, extremely informative and explains a lot of previously posted battery phenomena.
Click to expand...
Click to collapse
Lol....yea that FB app question was pretty brilliant I'll try to get in touch with CoreDroid folks, and see if they can answer my question.
I mean it does work, it's almost like a miracle to me.

I know. I just can't figure out WHY. Its been really bothering me.
Sent from my HTC Glacier using XDA App

Jessooca said:
Which battery calibration app are you using?
Sent from my HTC Glacier using xda premium
Click to expand...
Click to collapse
None, I am just surprised to see improved battery life after couple of 'full-drain, full-charge" operations.
BTW, care to suggest a good battery calibration app? Much appreciated.

well, the best battery calibration app Ive used is Battery Calibration by NeMa, but now after reading this thread it seems that they dont really do anything

ajrulez said:
None, I am just surprised to see improved battery life after couple of 'full-drain, full-charge" operations.
BTW, care to suggest a good battery calibration app? Much appreciated.
Click to expand...
Click to collapse
The drain-charge cycles is just a way to calibrate the battery- takes more time to "forget" the old stats, so people either use an app or manually delete the battery statistics so one can start accumulating fresh statistics.
After a few days you get your statistics right, from then on the battery indicator will be more or less accurate.
Battery drainage has nothing to do, really, with how many times you'll calibrate or drain/ charge or whatever. It has to do with how much you use screen on, Wifi, BT, gps, partial wakelocks, apps syncing etc. In other words- use your phone and be assured battery is going to drain. Leave it alone, let it sleep- battery will last a couple of days...
Sent from my HTC Glacier using Xparent Cyan Tapatalk

just to clarify, and sorry for butting in, but there is no such thing as "calibrating your battery"... this has been debunked by many people who understand android's Linux kernel and even an android engineer at Google.
the batterystats.bin file is simply that, a bin. it does nothing more than collect dumped statistics of what exactly has been using your battery, how long, how much power those processes used, etc. it has absolutely nothing to do with your phone's ability to display correct information about how much juice you have left - that function is within the Linux kernel which monitors, and controls power throughout the device.
ask yourself this... ever flashed a ROM with say 50% power left on a charge? what happens after your first boot? does your phone suddenly have no idea how much charge is left? no. it doesn't. because the new kernel you just flashed with your ROM is picking up right where you left off.
wiping battery stats is useless. period. it.does absolutely nothing to better battery life. that is fact. that is your phone. that is your Linux platform and straight truth in how it works.
and since it is stored in the data directory, every time you flash a ROM and wipe data, you are wiping the battery stats... so why do you boot up and do it again... I know... good question.
Sent from EVO 3D using XDA premium

aznprodgy said:
well, the best battery calibration app Ive used is , but now after reading this thread it seems that they dont really do anything
Click to expand...
Click to collapse
Hehe, yes I doubt if these battery calibration do anything.
estallings15 posted a very informative link in 2nd or 3rd post (of this thread)....all these battery calibration apps simply delete the battery stats file at least thats what one from NeMA does anyways

cobraboy85 said:
just to clarify, and sorry for butting in, but there is no such thing as "calibrating your battery"... this has been debunked by many people who understand android's Linux kernel and even an android engineer at Google.
the batterystats.bin file is simply that, a bin. it does nothing more than collect dumped statistics of what exactly has been using your battery, how long, how much power those processes used, etc. it has absolutely nothing to do with your phone's ability to display correct information about how much juice you have left - that function is within the Linux kernel which monitors, and controls power throughout the device.
ask yourself this... ever flashed a ROM with say 50% power left on a charge? what happens after your first boot? does your phone suddenly have no idea how much charge is left? no. it doesn't. because the new kernel you just flashed with your ROM is picking up right where you left off.
wiping battery stats is useless. period. it.does absolutely nothing to better battery life. that is fact. that is your phone. that is your Linux platform and straight truth in how it works.
and since it is stored in the data directory, every time you flash a ROM and wipe data, you are wiping the battery stats... so why do you boot up and do it again... I know... good question.
Sent from EVO 3D using XDA premium
Click to expand...
Click to collapse
Yep, agree with your comments 100%. After reading the link posted by estallings15 earlier in this thread, the myth of battery calibration was busted

I agree with most that Battery Calibration is a joke, and doesn't mean anything. However, batteries in many devices (not just our Cell Phones) seem to benefit from proper discharge/full charge cycles. In fact, it's usually recommended in things like electric RC cars that you completely run down the battery as far as you can go (realistically of course!) prior to charging; also to prolong battery life. I always notice at least slightly longer use times if I don't always pop the thing on a charger at 75%. But go with what works for ya, and of course some roms DO drain faster than others. And less screen haha

[Q] Battery defect or rom issue?

Hello!
Sorry I can't post this in the Paranoid Android thread yet. As a noob I can't post in that forum until I have 10 posts so I'm at a loss as to where I should post this.
Anyway, I just put the new 2.1799 PA ROM on my Nexus 7. Unfortunately, I seem to have a serious battery drain when the screen is on. I have read many posts where people claim to have easily achieved 6+ hours of active screen time per battery charge whereas I'm only getting 3-4 hours of active screen time per charge, almost all of it related to web surfing. I have a strong wifi signal and I keep my screen brightness around 20/30 range. I'm not sure if it's the ROM or if my battery is defective.
I have also read about a battery calibration app through a different thread. Is that necessary for the PA ROM? I didn't see anything in the tutorial mentioning a battery calibration.
Included are two pictures, although they aren't very indicative of my problem as my tablet was sitting in my backpack for most the day.
Please tell me I'm just being paranoid! Thank you for the help!

thatnoob said:
Hello!
Sorry I can't post this in the Paranoid Android thread yet. As a noob I can't post in that forum until I have 10 posts so I'm at a loss as to where I should post this.
Anyway, I just put the new 2.1799 PA ROM on my Nexus 7. Unfortunately, I seem to have a serious battery drain when the screen is on. I have read many posts where people claim to have easily achieved 6+ hours of active screen time per battery charge whereas I'm only getting 3-4 hours of active screen time per charge, almost all of it related to web surfing. I have a strong wifi signal and I keep my screen brightness around 20/30 range. I'm not sure if it's the ROM or if my battery is defective.
I have also read about a battery calibration app through a different thread. Is that necessary for the PA ROM? I didn't see anything in the tutorial mentioning a battery calibration.
Included are two pictures, although they aren't very indicative of my problem as my tablet was sitting in my backpack for most the day.
Please tell me I'm just being paranoid! Thank you for the help!
Click to expand...
Click to collapse
The battery recalibration is a myth, but there is also no harm in trying it.
according to the pics you have attached, there doesn't seem to be anything wrong.
Battery also drains faster if you have too many apps that have services running.
Ex: Facebook.

I know there is a battery warranty, but how bad does it have to be to get it replaced? My battery cannot reach the 9.5hrs of 720p video playback (with headphones in) as achieved by Asus. I can only get 8hrs. From normal usage, I am only able to get 6 hours.

The ROM has less to do with the battery than the kernel does.
I would say try flashing another kernel. The default cyanogenmod kernel that comes with Paranoid Android didn't give me very good battery life.
Franco kernel gives me excellent battery life. Other good ones for battery are Faux or Motley.
You might like reading this thread about kernels and battery life.
http://forum.xda-developers.com/showthread.php?t=1889571
Sent from my Paranoid Nexus 7

AlleN7 said:
I know there is a battery warranty, but how bad does it have to be to get it replaced? My battery cannot reach the 9.5hrs of 720p video playback (with headphones in) as achieved by Asus. I can only get 8hrs. From normal usage, I am only able to get 6 hours.
Click to expand...
Click to collapse
That is in the normal range i would say, Companies usually exaggerate.
As suggested try franco's kernel.
He has a free kernel flashing app on the play store.

My issue is with how the battery percentage is running down......
Charge the N7 to max and use it for a good 2 hours and the battery STILL reads 100%.
Even if I then shut down and reboot it still shows 100%, then all of a sudden it will start to drop very slowly at first until it gets to around 40% which it then shuts down and will not reboot, obviously void of any battery cells.
Clearly it's a calibration issue.
This is on a stock non-rooted machine.

vinny86 said:
That is in the normal range i would say, Companies usually exaggerate.
As suggested try franco's kernel.
He has a free kernel flashing app on the play store.
Click to expand...
Click to collapse
I tried his kernal. I did my video play back test and I got the same 8 hours as before. During normal usage I think I will get about 30-40 more minutes. Still not what others are getting

Beards said:
My issue is with how the battery percentage is running down......
Charge the N7 to max and use it for a good 2 hours and the battery STILL reads 100%.
Even if I then shut down and reboot it still shows 100%, then all of a sudden it will start to drop very slowly at first until it gets to around 40% which it then shuts down and will not reboot, obviously void of any battery cells.
Clearly it's a calibration issue.
This is on a stock non-rooted machine.
Click to expand...
Click to collapse
Try a factory reset. If that doesn't work, you're more than likely actually looking at it being a hardware issue.
Sent from my Nexus 7 using Tapatalk 2

najaboy said:
Try a factory reset. If that doesn't work, you're more than likely actually looking at it being a hardware issue.
Sent from my Nexus 7 using Tapatalk 2
Click to expand...
Click to collapse
Factory reset was the very first thing I tried when it started playing up.... I'm hoping when 4.1.2 rolls out it may clear it. If not then I'll have to look at doing a root and access the battery file to see if deleting may help.
Thing is a recharge should clear out the battery file stats and calibrate, which clearly it's not.
Apart from this the N7 is flawless so it's staying with me. Running hours is the same, just doesn't give an accurate reading of how the battery is running down.
It's not a big issue.... to be honest I'm more curious than annoyed.

Beards said:
Factory reset was the very first thing I tried when it started playing up.... I'm hoping when 4.1.2 rolls out it may clear it. If not then I'll have to look at doing a root and access the battery file to see if deleting may help.
Thing is a recharge should clear out the battery file stats and calibrate, which clearly it's not.
Apart from this the N7 is flawless so it's staying with me. Running hours is the same, just doesn't give an accurate reading of how the battery is running down.
It's not a big issue.... to be honest I'm more curious than annoyed.
Click to expand...
Click to collapse
Have you tried installing a 3rd party battery app to see if it registers the correct battery output? This is the one I have used, works good. GL
https://play.google.com/store/apps/details?id=net.hubalek.android.reborn.beta&hl=en

snipe2nite said:
Have you tried installing a 3rd party battery app to see if it registers the correct battery output? This is the one I have used, works good. GL
https://play.google.com/store/apps/details?id=net.hubalek.android.reborn.beta&hl=en
Click to expand...
Click to collapse
Yes thanks.... Tried quite a few. Nothing changes.

Beards said:
Factory reset was the very first thing I tried when it started playing up.... I'm hoping when 4.1.2 rolls out it may clear it. If not then I'll have to look at doing a root and access the battery file to see if deleting may help.
Thing is a recharge should clear out the battery file stats and calibrate, which clearly it's not.
Apart from this the N7 is flawless so it's staying with me. Running hours is the same, just doesn't give an accurate reading of how the battery is running down.
It's not a big issue.... to be honest I'm more curious than annoyed.
Click to expand...
Click to collapse
You do realize that wiping batterystats.bin has absolutely nothing to do with the battery fuel gauge, right? It does not "calibrate" the battery or affect reported charge. The myth of wiping battery stats has long since been debunked by Google's Android engineers. The only info contained in the file is a list of apps that used battery since the last full charge.
The only other thing you could do besides a factory reset is see if 4.1.2 fixes it for you. If not, then it's definitely hardware causing the issue- the battery charge is likely being improperly read and reported by the battery itself.
Sent from my Nexus 7 using Tapatalk 2

N7 JB 4.2 strange charging issue

My stock unrooted 16gb n7 received the 4.2 update this morning, all has been fine until this evening when it needed charge.
It often gets plugged into a htc phone charger, which has worked fine since i bought the tab a few months ago until today, its a 1amp charger so it takes ages to charge, but thats fine as it is plugged in until the morning normally.
So i plugin as normal, and come back after setting up google play music on my desktop pc, and i see the unit rebooting showing the glowing X. The screen goes blank and is unresponsive, eventually the google logo appears and it boots normally (its still plugged in btw), after unlocking the screen goes mental after maybe 5 seconds with random noise on it, then goes black.
So i unplug and use the genuine asus charger and cable, it does the same twice over, reboot, freeze, long wait then reboot.
I have now left it on charge using the asus charger and it seems to be ok now
Have google changed some charging requirements? Anyone else seen this?
Sent from my Nexus 7 using xda premium

Not sure, but my nexus 7 on Android 4.2 charges like 35% slower than did with 4.1.2..... what the hell did they do??

Funny you mention that, i might agree with you there
The N7 seems fine today, i did make a couple of videos of it misbehaving last night, watching back my circle battery widget app jumps from 16% to 0% battery just before it goes blank, indicating it might have simply run flat but thought it still had 16% battery?
Wonder if they have changed the battery meter scaling?
I think i will run it flat and check it shuts down properly like it used to
Sent from my Nexus 7 using xda premium

dexterslab said:
Funny you mention that, i might agree with you there
The N7 seems fine today, i did make a couple of videos of it misbehaving last night, watching back my circle battery widget app jumps from 16% to 0% battery just before it goes blank, indicating it might have simply run flat but thought it still had 16% battery?
Wonder if they have changed the battery meter scaling?
I think i will run it flat and check it shuts down properly like it used to
Sent from my Nexus 7 using xda premium
Click to expand...
Click to collapse
Hi dexterslab,
On a side note when you update to 4.2 were you already rooted and did you have superSU version0.98 installed? I have been reading other posts in this forum that folks have been rooted, superSU installed and the update has completely crashed their N7. ANy info would be greatly appreciated.
Thanks,
JBIRD

Its still as stock, locked and unrooted
Sent from my Nexus 7 using xda premium

I've noticed slower charging since the 4.2 update too - did a quick Google search and landed here. Using the same genuine Asus charger and generic cable that I did before the update, and I would agree with the roughly 35% slower estimate.

dexterslab said:
Its still as stock, locked and unrooted
Sent from my Nexus 7 using xda premium
Click to expand...
Click to collapse
Thanks, did you do a factory reset prior to updating?

No, update received ota so just installed it
Sent from my Nexus 7 using xda premium

Been working and charging fine since, guess it was just a random glitch!?
Sent from my Nexus 7 using xda premium

scubastevegk said:
I've noticed slower charging since the 4.2 update too - did a quick Google search and landed here. Using the same genuine Asus charger and generic cable that I did before the update, and I would agree with the roughly 35% slower estimate.
Click to expand...
Click to collapse
Are you using the new Daydream feature (you can find it in the display settings). If yes this may be the cause of slower charging, because it doesn't turn of the display.

Daydream is off.
Tbh, now it seems to have settled down i think maybe charging time is pretty much the same as it was. The whole debacle seems to be a complete non-event in hindsight!
Sent from my Nexus 7 using xda premium

Guhrasoh said:
Are you using the new Daydream feature (you can find it in the display settings). If yes this may be the cause of slower charging, because it doesn't turn of the display.
Click to expand...
Click to collapse
No Daydream for me.

Mine is stock and unrooted. After the update I'm having the same charging issues. Incredibly slower charging. It's been plugged in for 6 hours now and it's at 80%. I did play a bit of pandora for about 30minutes but it was still plugged in. Other than that I haven't touched it other than to check the level. I turned daydream. Let's see if that help though I doubt it.

i think when you install the 4.2 update it does a battery stat wipe. this could produce the battery jumping from 16%-0% i reset the battery stats on my gt-i9003 the other day charged, its went from 100% - 40% instantly after about 2 charge cycles it should go back to normal.
it would also explain the battery seeming to take longer to charge, its just the voltage counter resetting itself. it might even in some cases charge faster....then run out quicker....
charge- discharge about 3 times and it should go back to norm.:good:
example :
dexterslab said:
Tbh, now it seems to have settled down i think maybe charging time is pretty much the same as it was. The whole debacle seems to be a complete non-event in hindsight!
Click to expand...
Click to collapse
still bro i wouldnt use any charger expect the asus one, phones maybe i mean i always use other peoples chargers,or pickup the wrong end from my snake-pit of charger cables hanging under my tv unit. but for tabs....nah lol

chismay said:
i think when you install the 4.2 update it does a battery stat wipe. this could produce the battery jumping from 16%-0% i reset the battery stats on my gt-i9003 the other day charged, its went from 100% - 40% instantly after about 2 charge cycles it should go back to normal.
it would also explain the battery seeming to take longer to charge, its just the voltage counter resetting itself. it might even in some cases charge faster....then run out quicker....
charge- discharge about 3 times and it should go back to norm.:good:
example :
still bro i wouldnt use any charger expect the asus one, phones maybe i mean i always use other peoples chargers,or pickup the wrong end from my snake-pit of charger cables hanging under my tv unit. but for tabs....nah lol
Click to expand...
Click to collapse
Agreed, phones seem to be more universally compatible when it comes to charges.
Charge a tab with the wrong charger n you'll make up with a melted Nexus 7

i think its a part of certain regulations now that mobile phones needs to have an internal capacitor/transformer to make sure of this problem, as people usually run out of charge on the go and use other chargers as long as the connector fits and it begins charging, most of us including me are probably guilty of plugging a charger in, seeing its charging and thinking *yay it works fine* walking away and not really understanding what slow-fast damage can be caused to the device/battery.
for tabs 30% i would say dont have this feature:good: especially the Chinese ones. ? <no racial offence intended> you guys know what im on about.

My Nexus 7 worked great before upgrading to 4.2. Now it can't charge while I'm using it... The battery just goes up and down as I'm surfing the web, if I load a lot of pages, it goes down, if I read a lot, it goes up... But if I try to watch a floating video while surfing the web, it just goes down... There is definitely a problem! Here is a screenshot... I'm using the original charger and cable...

chismay said:
i think when you install the 4.2 update it does a battery stat wipe. this could produce the battery jumping from 16%-0% i reset the battery stats on my gt-i9003 the other day charged, its went from 100% - 40% instantly after about 2 charge cycles it should go back to normal.
it would also explain the battery seeming to take longer to charge, its just the voltage counter resetting itself. it might even in some cases charge faster....then run out quicker....
charge- discharge about 3 times and it should go back to norm.:good:
example :
still bro i wouldnt use any charger expect the asus one, phones maybe i mean i always use other peoples chargers,or pickup the wrong end from my snake-pit of charger cables hanging under my tv unit. but for tabs....nah lol
Click to expand...
Click to collapse
Wiping battery stats does absolutely nothing that affects reported battery charge level. That wives' tale was long ago debunked by a member of Google's Android team. The one and only thing you are wiping is a list of apps that have operated on battery since unplugging after the last complete charge. This in no way, shape, or form affects reported charge or has any effect on battery life whatsoever.
Sent from my Galaxy Nexus using Tapatalk 2

najaboy said:
Wiping battery stats does absolutely nothing that affects reported battery charge level. That wives' tale was long ago debunked by a member of Google's Android team. The one and only thing you are wiping is a list of apps that have operated on battery since unplugging after the last complete charge. This in no way, shape, or form affects reported charge or has any effect on battery life whatsoever.
Sent from my Galaxy Nexus using Tapatalk 2
Click to expand...
Click to collapse
LIKE I AM SAYING MY FRIEND,
actually the battery stats ARE WHAT THE GOOGLE DEV SAID is what gives you accurate readings it doesn't increase your battery life . i never said that it will, so please don't police me,.
heres the comment
This file [batterystats.bin] 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."
when you flash a new firmware, the system must calibrate as there are no previous readings from the bstat file right?.,these are the readings that help the system produce the reported battery charge. its what it does to give you those readings, i was guiding the above member to wait and run a few cycles for readings to be more accurate i never said his battery was dead.
kinda why pretty much EVERYONE mentions after flashing a new firmware on most device they have a few days of battery "up-n-downs"= counter reset/data collection/last battstat file wiped.
cheers:good:

chismay said:
LIKE I AM SAYING MY FRIEND,
actually the battery stats ARE WHAT THE GOOGLE DEV SAID is what gives you accurate readings it doesn't increase your battery life . i never said that it will, so please don't police me,.
heres the comment
This file [batterystats.bin] 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."
when you flash a new firmware, the system must calibrate as there are no previous readings from the bstat file right?.,these are the readings that help the system produce the reported battery charge. its what it does to give you those readings, i was guiding the above member to wait and run a few cycles for readings to be more accurate i never said his battery was dead.
kinda why pretty much EVERYONE mentions after flashing a new firmware on most device they have a few days of battery "up-n-downs"= counter reset/data collection/last battstat file wiped.
cheers:good:
Click to expand...
Click to collapse
Read her entire dissertation, and you will see that it does not pertain to reported charge level. She explicitly states that batterystats.bin has no bearing on reported charge level. Interesting that you left out the portions of her post immediately prior to, and immediately following, the part of her post that you quoted... you know, the ones where she states, and then restates, that nothing in batterystats.bin affects the reported charge level? Also, the reason the battery seems more stable a few days after flashing new firmware is the kernel itself settling, not the OS.
Sent from my Nexus 7 using Tapatalk 2

Wiping Battery stats and Battery Calibration Myth gets Debunked

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/andro...-battery-stats-does-not-improve-battery-life/
maybe a mod will sticky this as i think it needs to be at the top of the page so people can see it .......

Hackborn, excellent name. Sounds like my kinda girl
Edit; Found another interesting article by her about android multitasking http://android-developers.blogspot.co.uk/2010/04/multitasking-android-way.html
(With a pic)

Robbie P said:
Hackborn, excellent name. Sounds like my kinda girl
Edit; Found another interesting article by her about android multitasking http://android-developers.blogspot.co.uk/2010/04/multitasking-android-way.html
(With a pic)
Click to expand...
Click to collapse
nice find Robbie
hey im gonna pm you about a couple apps you might like

Thank you so much! Even I do not own HTC Leo: HD2 this is still important for us Galaxy Y owners , Can I put this on our Forums and linking a thread here so they know who to thank? and a credits to you also as well . Thanks button pressed.

Sean De Jesus said:
Thank you so much! Even I do not own HTC Leo: HD2 this is still important for us Galaxy Y owners , Can I put this on our Forums and linking a thread here so they know who to thank? and a credits to you also as well . Thanks button pressed.
Click to expand...
Click to collapse
your welcome
yes you can add to to your forum section
no credits to me are needed i just posted it from the xda news page

my htc hd2 wired problem .. my battery drains very fast.. . if i connect power cable after some time phone boots... some times while charging itself my phone switched off.. screen dark.. only liberates no display...
is it problem with my battery..or phone hardware issue...
me changed different rom.. and sd card. two years worked very well .. without any issues.. no Im in big trouble..with this phone
help me

The phone's supposed to turn on while charging when off in MAGLDR, that's completely normal. The high drain could be caused by any number of things and since there are various guides around as to how to reduce your battery drain I'm not going to get into it right now. The other issue you have is (I assume, the wording's a bit difficult to understand) an SOD or 'sleep of death'. Try flashing a newer ROM because afaik this issue doesn't exist on modern HD2 ROMs at all.

cool, good to know.

this is the question about li-ion battary. Smn says that better to charge from 0 to 100. and use from 100 to 0, but theoretically, this kind of battery better be used from 20 for 80 percent. So, there is a lot of things to debate.