# Battery Calibration questions



## dpaine88 (Jul 21, 2011)

Hey all, I got my Nexus two days ago and rooted it ASAP, and did flash my first ROM at 100% battery like I did on the Droid.

However, I have not really let the phone get below 50% and have been charging it a lot. I read though that I should let it go through several "power cycles", does this mean charge to full, then let the phone die and turn off then repeat?

As far as deleting battery stats, I have seen 2 methods that are opposites of the other. In one, you do several power cycles then wipe battery stats and you are good to go. The other one, you wipe stats first, then do the power cycles. Which one is correct?

Lastly, I know on the Droid I only worried about battery stats in reference to flashing ROMs in which I wiped data. Is there a need to be at 100% battery when flashing kernels? or just ROMs

Thanks!!


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## anotherfiz (Sep 23, 2011)

Drain it to dead, pull the battery, reseat, turn phone on. it will be at like <20%. Drain it again, rinse and repeat.

Do this till the phone stops booting.

Then keep the phone off and charge it to full (give it a good 4 hours).

ICS calibration is one of the contributing factors to battery drain, old methods are not reliable.

Also, turn off location services and set wifi on during sleep to never. this will fix the android OS issues.


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## dpaine88 (Jul 21, 2011)

Thanks a lot, very helpful!


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## elektroshok (Dec 24, 2011)

[

When do you reset stats in recovery?

Sent from my Galaxy Nexus using Tapatalk


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## elektroshok (Dec 24, 2011)

[

When do you reset stats in recovery?

Sent from my Galaxy Nexus using Tapatalk


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## anotherfiz (Sep 23, 2011)

Using my method you shouldnt reset stats in recovery. I dont think that resetting stats in recovery is helping people at this point in time


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## morbidz (Jul 20, 2011)

With the phone off and charging how would I know when to remove from charger? Just wait 4 hrs?

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## anotherfiz (Sep 23, 2011)

4-5ish just to be sure, assuming that you're using the wall charger that came with it, i think 4 would be more than enough


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## dpaine88 (Jul 21, 2011)

Can you elaborate why the tradional methods dont work? Doesnt the batterystats file just get wiped every time you flash a ROM?

I thought draining a Liithium ion battery to the bottom was very bad for it.


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## thescreensavers (Jun 8, 2011)

^ yes it is very bad for it, it cuts its life down, which is why I never will intentionally drain my battery.

Being that this is a removable battery it isnt such a huge deal since you can just buy a new one.


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## Brian (Jun 7, 2011)

dpaine88 said:


> I thought draining a Liithium ion battery to the bottom was very bad for it.


I've always heard the same....jury still out on this method

Sent from my Galaxy Nexus using Tapatalk


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## Burncycle (Aug 6, 2011)

http://batteryuniver...based_batteries

This website is great for those who like to completely discharge







Just some cool facts. It is definitely counter productive to completely drain your battery on a regular basis. I know I charge whenever I can as you can easily triple the number of complete discharges from it by charging it more often.


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## dpaine88 (Jul 21, 2011)

So sounds like it is pretty bad to fully drain the battery...can anyone shed some light on to how to properly calibrate the battery then?


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## P-bottie (Dec 24, 2011)

Also can we edit that post. Luckily I only drained and pulled and redrained one time. That misinformation needs to go away.


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## Burncycle (Aug 6, 2011)

dpaine88 said:


> So sounds like it is pretty bad to fully drain the battery...can anyone shed some light on to how to properly calibrate the battery then?


Just do it the normal way. Draining it once or twice isn't going to be a big deal. I'm just saying to do your best to not make a habit of it. That post was more for people who drain the phone every time they charge to keep it "calibrated". Try to flash your roms with full battery and plugged in etc.. And as said before, you can always buy a new battery down the road


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## swimminsurfer256 (Sep 23, 2011)

So worst-case it seems as though completely draining your battery will drop the capacity to 70% over around a years time (if you use around 1 cycle per day which seems to be the general trend). This means that by the end of the year you'll likely buy another battery. Lots of us already bought an extra extended battery and I even bought an extra regular battery because it came with the external charger I got. This means I'm basically set for almost 3 years of 100% discharge daily which is extremely unlikely anyways since I'll have a new phone in probably a year's time


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## anotherfiz (Sep 23, 2011)

I think I should be clear, I'm not recommending this is how you charge battery every time. But only the first time, I say this because when you reboot a battery that you've pulled you will notice that you have some time as much is 50 percent extra. We're not talking about the bottom 5 percent here , we're talking about an entire extra quarter of the battery. I c s is simply not reading the proper battery stats out of the box. This has about as much potentil of hurting your battery as overclocking does of hurting your processor - only if you do it abusively. The phone and batteries are designed to the phone won't even boot if the battery is under 5 true percent


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## poontab (Jun 7, 2011)

Brian said:


> I've always heard the same....jury still out on this method
> 
> Sent from my Galaxy Nexus using Tapatalk


Well you're not likely to be able to trick it into booting with less than 3200-3000mv. Which 3000mv is about 500mv above where the damage threshold is.

As far as battery stats go that is an almost worthless exercise as the file is rebuilt every time you flash a ROM. If you're really into deleting this file just delete it upon every boot. Your % will not be very far off & you won't get better or worse battery life as the your phone will shut down upon reaching ~3200mv regardless of what the displayed % says.


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## mtw4991 (Aug 31, 2011)

Just a comment, see the Battery Calibration thread for the Nexus One on XDA if you need confirmation. Most quality batteries are calibrated correctly, meaning they charge to 100% and die at 0% or <1%. Fully charging with the phone ON and draining til empty/auto-shutdown a couple of times allows the batterys' chip to learn its full40 point(true 100%) and its' empty point. Then you can get the most out of the battery. In order to accomplish this, you need to be able to get the battery into "learn mode". We created an app for the N1 that allows us to calibrate it correctly. On the GN, you can force it into Learn Mode by inserting the charge cable into the charge port at the moment it goes into auto-shutdown mode(you gotta be ready and really, really quick). Once it gets above 80% charged, put it into Airplane mode so no apps/processes draw power which might artifically cause it to reach 100% too soon(measured by -mv draw). Once in airplane mode, leave it alone for a couple of hours(til 100% charged), then reboot. Hope this helps clarify the confusion.


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## anotherfiz (Sep 23, 2011)

poontab said:


> Well you're not likely to be able to trick it into booting with less than 3200-3000mv. Which 3000mv is about 500mv above where the damage threshold is.


What this guy said.

I urge you guys to look at the number of posts regarding people who report inconsistent battery drain, and even battery gain while their batteries are un-calibrated. This is just a fast method to get your battery calibrated right the first time.

Understand, the phone *will not boot* if you're at the low threshold of the battery. The phone, however, has been known to think a battery is dead when it is in fact at 20 - 50%


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## saikano17 (Dec 27, 2011)

mtw4991 said:


> On the GN, you can force it into Learn Mode by inserting the charge cable into the charge port at the moment it goes into auto-shutdown mode(you gotta be ready and really, really quick). Once it gets above 80% charged, put it into Airplane mode so no apps/processes draw power which might artifically cause it to reach 100% too soon(measured by -mv draw). Once in airplane mode, leave it alone for a couple of hours(til 100% charged), then reboot. Hope this helps clarify the confusion.


when you plug the charger in when its in auto shut down mode, is phone suppose to stay up? or shut down regardless?

Sent from my Galaxy Nexus using Tapatalk


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## waylo (Aug 31, 2011)

mtw4991 said:


> Just a comment, see the Battery Calibration thread for the Nexus One on XDA if you need confirmation. Most quality batteries are calibrated correctly, meaning they charge to 100% and die at 0% or <1%. Fully charging with the phone ON and draining til empty/auto-shutdown a couple of times allows the batterys' chip to learn its full40 point(true 100%) and its' empty point. Then you can get the most out of the battery. In order to accomplish this, you need to be able to get the battery into "learn mode". We created an app for the N1 that allows us to calibrate it correctly. On the GN, you can force it into Learn Mode by inserting the charge cable into the charge port at the moment it goes into auto-shutdown mode(you gotta be ready and really, really quick). Once it gets above 80% charged, put it into Airplane mode so no apps/processes draw power which might artifically cause it to reach 100% too soon(measured by -mv draw). Once in airplane mode, leave it alone for a couple of hours(til 100% charged), then reboot. Hope this helps clarify the confusion.


mtw4991, good to see you here.

I posted a very long summary of that work here:
http://forum.xda-developers.com/showthread.php?t=1423054

RogerPodacter even made a guest appearance to makes some comments on the GNex battery. Unfortunately not as open/modable as the N1.


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## dpaine88 (Jul 21, 2011)

Edit: nvm...see posts below
Sent from my Galaxy Nexus using RootzWiki


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## dpaine88 (Jul 21, 2011)

Two things
1) Waylo, awesome work on that writeup at xda, I learned a lot!! So was RogerP right? There is no learn mode in the gnex battery?

2) I've seen mentioned a few times that people should flash ROMs at 100% battery, if we do this, do we need to do the drain n charge or it is calibrated automatically?

Sent from my Galaxy Nexus using RootzWiki


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## dpaine88 (Jul 21, 2011)

anotherfiz said:


> Using my method you shouldnt reset stats in recovery. I dont think that resetting stats in recovery is helping people at this point in time


Hate to triple post but I am the OP so screw it.

With your method, since we are not talking about the battery stats file, will this new calibration method persist through ROMs? Since there is so many updates and new ROMs, I find myself wiping data pretty often and don't want to kill my battery draining to zero a few times a week

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## Mustang302LX (Jun 28, 2011)

dpaine88 said:


> Two things
> 1) Waylo, awesome work on that writeup at xda, I learned a lot!! So was RogerP right? There is no learn mode in the gnex battery?
> 
> 2) I've seen mentioned a few times that people should flash ROMs at 100% battery, if we do this, do we need to do the drain n charge or it is calibrated automatically?
> ...


I've personally never flashed a ROM at 100% battery. I flash the ROM and set it all up then power the phone off and charge it overnight. Boot it up into CWM wipe battery stats and move on with life. Never had an issue with incorrect percentages or bad battery drain.


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## dpaine88 (Jul 21, 2011)

Mustang302LX said:


> I've personally never flashed a ROM at 100% battery. I flash the ROM and set it all up then power the phone off and charge it overnight. Boot it up into CWM wipe battery stats and move on with life. Never had an issue with incorrect percentages or bad battery drain.


Thanks for the real world answer, very helpful.

Do you just use phone as normal after wiping stats? Do you let it drain down to 0 then charge to full? Not reboot at all?

Sent from my Galaxy Nexus using RootzWiki


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## Mustang302LX (Jun 28, 2011)

dpaine88 said:


> Thanks for the real world answer, very helpful.
> 
> Do you just use phone as normal after wiping stats? Do you let it drain down to 0 then charge to full? Not reboot at all?
> 
> Sent from my Galaxy Nexus using RootzWiki


After I wipe I use the phone as I normally would and when I go to bed I charge it no matter what percentage I'm at at the time. Like I said I've yet to see my phone die at what would seem a high percentage readout 20%+). No crazy battery drain or anything really.


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## TeeX (Jun 6, 2011)

thanks for the info - I think we're all learning as we go about getting the best battery life out of 4G/ ICS devices.

Question:
I have two regular (1850) batteries. Should I rotate them regularly, and if so- how often? Or once I "calibrate" a battery, should I run it for a long time then just let the other battery be my "just in case" battery?


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## cvhovey (Jun 11, 2011)

Going to try draining my battery down and see how that works, but on the extended battery, having a long wait to get it down low. ;-)

I'd also be curious to know about the battery rotation issue (per TeeX) as well. It seems with my Droid X, if I left a battery sitting for a couple weeks without use, its performance would suffer (at least initially). At the same time, with the stock battery and extended battery, not sure how it affects the stats if swapping those out too often.


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## cantcurecancer (Jul 30, 2011)

You do not need to drain your battery all the way, or reset battery stats from CWM to "recalibrate" it. The Galaxy Nexus has a max17040 fuel gauge which does its own monitoring of the battery and auto-caliberates itself via it's own hardware/firmware and reports it back to Android.

Source: Brian Klug from Anandtech.com



Website said:


> No Full-to-Empty Battery Relearning Necessary
> 
> ...Unlike traditional fuel gauges, the ModelGauge algorithm eliminates the need for battery relearn cycles and an external current-sense resistor.


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## dpaine88 (Jul 21, 2011)

cantcurecancer said:


> You do not need to drain your battery all the way, or reset battery stats from CWM to "recalibrate" it. The Galaxy Nexus has a max17040 fuel gauge which does its own monitoring of the battery and auto-caliberates itself via it's own hardware/firmware and reports it back to Android.
> 
> Source: Brian Klug from Anandtech.com


Great, thanks for the post and with a quality source!

So basically we can do whatever the hell we want with the battery and it won't matter?

Sent from my Galaxy Nexus using RootzWiki


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## Notorious478 (Aug 9, 2011)

I've got the extended battery and I've noticed that randomly the battery gains a percent or two while off the charger. I used the battery calibration app but I'm wondering if I need to do something else?


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## MistaWolfe (Oct 10, 2011)

Wiping battery stats is a myth that was debunked by a lead Google engineer.

I'd link it, but it's Saturday and that's too much work. Google "Dianne Google battery stats Google+" and I bet you find it.

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## Notorious478 (Aug 9, 2011)

OK,good to know calibrating is a waste of time. Is it normal for my battery to go up 1-3 percent 1 or 2 times a day?


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## Helltoupee (Jun 12, 2011)

Notorious478 said:


> OK,good to know calibrating is a waste of time. Is it normal for my battery to go up 1-3 percent 1 or 2 times a day?


Yes. If the phone is under moderate to heavy use it will start to "estimate" battery drain kind of and when the drain normalizes it will recalculate the actual reading. This will in many cases result in the battery graph bumping up a few percent.

Sent from my Galaxy Nexus using Tapatalk.


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## monky_1 (Aug 26, 2011)

Mine phone is so odd

Galaxy


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## hazard209 (Aug 1, 2011)

monky_1 said:


> Mine phone is so odd
> 
> Galaxy


Ummm. Those lines breaking the flow of your discharge are system freezes.. It's not odd, it's just not functioning correctly.

sent from Ziggy, while calculating the next leap home


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## Helltoupee (Jun 12, 2011)

hazard209 said:


> Ummm. Those lines breaking the flow of your discharge are system freezes.. It's not odd, it's just not functioning correctly.
> 
> sent from Ziggy, while calculating the next leap home


Could be the system freezing and or unnoticed soft or hard reboots. But something looks borked for sure.

Sent from my Galaxy Nexus using Tapatalk.


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