Battery Calibration Debunked (By Actual Google Android Dev)

[mark manning]

Dianne Hackborn - 6:42 PM - Public 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 for away.



Source:

https://plus.google.com/u/0/105051985738280261832/posts/FV3LVtdVxPT

 

[overthinkingme]

Finally.

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[mrmako777]

nice find. guess the perceived improvement in battery accuracy/life is all placebo

 

[Jack_R1]

nice find. guess the perceived improvement in battery accuracy/life is all placebo

Yes, like so many other things...

 

[richdaley]

nice find. guess the perceived improvement in battery accuracy/life is all placebo

Is that what wipe battery stats does? I have never noticed any difference when I did that. To think of all the times I have run the battery down, cleared the stats, charged it, and cleared the stats again with no noticeable results.

Sometimes it seems like the battery life gets thrown off by flashing a new rom. It isn't necessarily getting worse battery life but the indicator will work funny like it will show 99% for 3 hours and I will think I am getting great battery life and then go to 30 in the next 20 minutes. It is like the UI gets confused. My tablet will sometimes say "connect your charger" even though the battery and indicator are 100%.

I don't think people realize how much drain the display is on the battery. They flash a cool rom and use it a lot and then think they are getting bad battery life because the display has been on for two hours while they play with it. It is amazing the amount of difference I get between when I am fidgeting with my phone while I am at work (have to recharge during the day) and when I am at home on the weekend and it sits on the kitchen table most of the time (it will generally go all weekend without a charge).

 

[eqjunkie829]

Wonder why its even an option to wipe battery stats with apps or recovery if it doesnt do anything. I never saw a difference myself, I just wiped them periodically cause others seemed to think it made a difference.

 

[jayb222]

Always worked for me. Been flashing since g1 days. whatever

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[mark manning]

Always worked for me. Been flashing since g1 days. whatever

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Ya well she helped make the original rom for your g1 so she must be wrong. The thickness of some peoples head

Sent from my Galaxy Nexus

 

[eqjunkie829]

Ya well she helped make the original rom for your g1 so she must be wrong. The thickness of some peoples head

Sent from my Galaxy Nexus

+1 lol

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[HTC Glacier]

First of all those of us who actually knows about Android OS really knows that /data/system/batterystats.bin is nothing more than stats audit. Now if you think you can't actually re-calibrate battery and project that data than your a fool. It has nothing to do with that file.

First of all to accurately predicate it you need a true daemon that's capable of tracking system data with full autonomy access. Second you need correct battery specs from the manufacturer. As reading memory from it may or not even be supported by the device kernel if its not allocated. Thus you see issues with cross link batteries on stock roms, but some is exceptional with similar size, specs.

Now to project the correct data from ~1-100% you need to fully discharge for it to cycle. Yes I know some of you maybe saying never fully discharge Li-Io but if you know the min mV rating then you can stop near suggested mV as it won't go below and damage cells. From then the duration of full charge is defined along with total available mAh. By calculating discharged -mA draw pre scale unit over empty estimation you can predict the true battery percentage.

Ex: ATM my uptime is 14h 47m at 65% with moderate usage (talk, txt, web). Since I have MP1650mAh battery I'm currently at 1072mAh. As its drawing -90mA per scale unit with 4156mV. At this current rate fully projected empty estimation is 9h 38m. Keep in mind my deviceis highly optimized and is on very aggressive battery saving mode.

Sent from my HTC Glacier

 

[mark manning]

First of all those of us who actually knows about Android OS really knows that /data/system/batterystats.bin is nothing more than stats audit. Now if you think you can't actually re-calibrate battery and project that data than your a fool. It has nothing to do with that file.

First of all to accurately predicate it you need a true daemon that's capable of tracking system data with full autonomy access. Second you need correct battery specs from the manufacturer. As reading memory from it may or not even be supported by the device kernel if its not allocated. Thus you see issues with cross link batteries on stock roms, but some is exceptional with similar size, specs.

Now to project the correct data from ~1-100% you need to fully discharge for it to cycle. Yes I know some of you maybe saying never fully discharge Li-Io but if you know the min mV rating then you can stop near suggested mV as it won't go below and damage cells. From then the duration of full charge is defined along with total available mAh. By calculating discharged -mA draw pre scale unit over empty estimation you can predict the true battery percentage.

Ex: ATM my uptime is 14h 47m at 65% with moderate usage (talk, txt, web). Since I have MP1650mAh battery I'm currently at 1072mAh. As its drawing -90mA per scale unit with 4156mV. At this current rate fully projected empty estimation is 9h 38m. Keep in mind my deviceis highly optimized and is on very aggressive battery saving mode.

Sent from my HTC Glacier

http://batteryuniversity.com/learn/article/how_to_prime_batteries

The truth is out there

Sent from my Galaxy Nexus

 

[HTC Glacier]

http://batteryuniversity.com/learn/article/how_to_prime_batteries

The truth is out there

Sent from my Galaxy Nexus

And that is why you don't allow fools to use Google. Do you actually understand or comprehend what was said? Let me ask you this why do you think they "wipe batterystats"? What's the reason for it? lol he thinks you can't predict actual mV/mAh of battery based on mA draw lol now that isfunny. The whole reason of having any UI battery metter was based on what logic? Next time you Google.com something make sure you actually comprehend what was the logic behind it. Hey all THE truth is out there...

Sent from my HTC Glacier

 

[mark manning]

And that is why you don't allow fools to use Google. Do you actually understand or comprehend what was said? Let me ask you this why do you think they "wipe batterystats"? What's the reason for it? lol he thinks you can't predict actual mV/mAh of battery based on mA draw lol now that isfunny. The whole reason of having any UI battery metter was based on what logic? Next time you Google.com something make sure you actually comprehend what was the logic behind it. Hey all THE truth is out there...

Sent from my HTC Glacier

The sad part was I was backing up on what you said. Calm down read it in lame mans terms before you trip.

Sent from my Galaxy Nexus

 

[estallings15]

Man, its getting hot in here. Lol.

Ok, so, if wiping battery stats is useless because it does NOTHING to the battery, is there a way to address the battery and force it to allow a slight overcharge on a regular basis, thereby shutting charging off at a higher capacity?

Please forgive my ignorance gentleman, and refrain from verbally bashing me.

I bought a 1550 mAh Anker battery. If I charge it to 100% and then use it, it stays at 100% for hours. Is this because my phone is waiting for it to drop below 1400 mAh, or what? If that's the case can I somehow tell my phone to consider 1550 mAh 100%?

I ask because of the mugen power app on the market. It intrigued me. Though there is a chance its a bunch.of balogna.

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[HTC Glacier]

The sad part was I was backing up on what you said. Calm down read it in lame mans terms before you trip.

Sent from my Galaxy Nexus

sorry I knew that was another possibility, my mistake. I thought the link you posted some how undermines what I said as you quoted me. As I only posted how to accurately predict and report battery data. Also I think you know who I am...

Man, its getting hot in here. Lol.

Ok, so, if wiping battery stats is useless because it does NOTHING to the battery, is there a way to address the battery and force it to allow a slight overcharge on a regular basis, thereby shutting charging off at a higher capacity?

Please forgive my ignorance gentleman, and refrain from verbally bashing me.

I bought a 1550 mAh Anker battery. If I charge it to 100% and then use it, it stays at 100% for hours. Is this because my phone is waiting for it to drop below 1400 mAh, or what? If that's the case can I somehow tell my phone to consider 1550 mAh 100%?

I ask because of the mugen power app on the market. It intrigued me. Though there is a chance its a bunch.of balogna.

Sent from my HTC Glacier using XDA App

That is THE prime reason people "wipe batterystats.bin" thinking it would fix staying for hours at 100% delay and heavy drop in short time. Which is sign of missing true data. Normally its measured via min/max mV and available mAh. Now by subtracting the used mA per scale unit the empty estimation is calculated. Thus projecting power draw at given duration and near accurate battery metter.

Sent from my HTC Glacier

 

[mark manning]

sorry I knew that was another possibility, my mistake. I thought the link you posted some how undermines what I said as you quoted me. As I only posted how to accurately predict and report battery data. Also I think you know who I am...





That is THE prime reason people "wipe batterystats.bin" thinking it would fix staying for hours at 100% delay and heavy drop in short time. Which is sign of missing true data. Normally its measured via min/max mV and available mAh. Now by subtracting the used mA per scale unit the empty estimation is calculated. Thus projecting power draw at given duration and near accurate battery metter.

Sent from my HTC Glacier

kinda wondered if that was you, didnt have your typical avatar tho

Sent from my Galaxy Nexus

 

[wealthy23]

So with this being said then you don't have to worry about your battery percentage between flashing roms?

The battery life should be still accurate?

I have a 1700mah
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[estallings15]

That is THE prime reason people "wipe batterystats.bin" thinking it would fix staying for hours at 100% delay and heavy drop in short time. Which is sign of missing true data. Normally its measured via min/max mV and available mAh. Now by subtracting the used mA per scale unit the empty estimation is calculated. Thus projecting power draw at given duration and near accurate battery metter.

Sent from my HTC Glacier

Yes, of course it is the prime reason. My question was, is there a way to tell the phone that 1550 is 100% or do I just deal with inaccurate monitoring that is based on a 1400 mAh battery?

Or, alternatively, will android figure it out over time and adjust for me?

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[mrmako777]

answer me this: why in miui does the hardware led light up green when miui tells me im only at 90%? when i check the mv with the battery calibration app it tells me im at 4220 which is a full charge...what makes miui not see that the battery is full?

 

[jayb222]

Before battery calibration, regardless of what happens, I was getting 9 hours, light usage. After battery calibration I get 19 hours, medium use. I'll stick with it with my thick headed self.

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