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[NOTICE] Battery % Reading Myth

OP morrislee

24th February 2012, 07:10 AM   |  #1  
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I know there was a recent Google announcement regarding battery status wipe, however, I found the results otherwise.

Seems that many individual now trusted official Google's spokes person, I would like you take you back on our side regarding the battery reading issue.

Another reason for this post is to make sure all the ROM flashers out there understand that it is probably not the ROM's fault but the battery meter is off. On top of the above, due to the fact that recent comments to all the ROMs has been "battery for this ROM is horrible" or "This ROM has awesome battery life!" before they have fully tested the entire battery cycle.

What Google is pointing out is not necessary "wrong" but it is misleading. They are implying that users are considering the Li-ion batteries to have "memory" effect like NiMH, yes, some users may still believed so. However! To fully "wipe" the battery level, you must understand that the Li-ion crystals inside the battery does not have memory effect, it does have a "meter" that reports the battery status. This meter is used to make sure all the cells in the battery is equally consumed properly, but during a ROM install, CWM restore, these values gets confused from time to time somehow in the software level.

Now, you must think that I have no facts to say Android OS is responsible for controlling that meter's data, but my experiences has proved to be convincing.

A simple example for the case to be more clearly explained is something what I have experienced before. After new ROM installs or CWM restores, I have the following experiences regarding the battery percentage reading.

Case 1: Battery lasts almost another hour with screen on with ONLY 1% left.
Case 2: Phone turns off without reaching 0%, sometimes as high as 8% my phone turns off.

The above 2 cases happens usually when the new ROM is installed and usually would have a battery reading far off from right before the ROM install or restore. They usually result in battery not being able to be appeared fully charged or in some cases in CM9 that the percentage goes above 100%

I hope the above has convinced you that "battery wipe" is necessary from time to time or cases to cases, also note that pulling the battery when the phone freezes sometimes would case the same issue.

If you are convinced, you may use the following steps to "wipe battery status" or "calibrate" is more precised term here:
  1. Run the phone until it turns off and cannot be turn on
  2. Plug it into a wall charger and ONLY wall chargers (because computer USB ports will boot Atrix)
  3. Wait until the big battery charging animation reaches 100%
  4. Boot into recovery and wipe battery status
  5. Reboot the phone

You should now have a "calibrated" battery meter at a hardware level where Android OS was not interfering with the meter AT ALL . You might be able to charge to 99% at most of the time, but that is fairly calibrated, can check if the voltage is at 4203mV to be sure.
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24th February 2012, 05:06 PM   |  #2  
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My battery when on cm7 won't charge past 4196 but if I flash miui it hits 4204,it's weird.

One thing I do to is before and during flashes I make sure I'm at 100% and still plugged in on the wall charger. This helps alot.

Sent from my MB860 using xda premium
Last edited by msd24200; 24th February 2012 at 05:09 PM.
24th February 2012, 06:42 PM   |  #3  
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Quote:
Originally Posted by morrislee

I know there was a recent Google announcement regarding battery status wipe, however, I found the results otherwise.

What Google is pointing out is not necessary "wrong" but it is misleading.

Not trying to pick a fight, but I just wanted to point out that what they say regarding battery stats isn't misleading. Batterystats.bin and "battery status" are not related. The battery stats that everyone wipes in CWM are exactly what the Android Engineer said they are, usage statistics for battery consumption by apps. (which always get wiped any time you reach a full charge) Batterystats.bin has no effect on what battery life is being shown.

Quote:
Originally Posted by morrislee

Now, you must think that I have no facts to say Android OS is responsible for controlling that meter's data, but my experiences has proved to be convincing.

A simple example for the case to be more clearly explained is something what I have experienced before. After new ROM installs or CWM restores, I have the following experiences regarding the battery percentage reading.

Case 1: Battery lasts almost another hour with screen on with ONLY 1% left.
Case 2: Phone turns off without reaching 0%, sometimes as high as 8% my phone turns off.

The above 2 cases happens usually when the new ROM is installed and usually would have a battery reading far off from right before the ROM install or restore. They usually result in battery not being able to be appeared fully charged or in some cases in CM9 that the percentage goes above 100%

The battery reporting over 100% in CM9 was a kernel issue (checkout this commit). If you browse through the entire file for that commit, you will see the battery % reading is also handled there (search for battery_state), and you will see it's tied to the battery reaching 4200mV.
-----------------------------------------------------------------------------
Other than that, thanks for trying to clarify the "horrible battery" problem people always seem to think they have. Yesterday I saw someone asking about battery life 20 minutes after Notorious updated Neutrino, lol.
Last edited by ghost_og; 24th February 2012 at 06:51 PM.
24th February 2012, 06:55 PM   |  #4  
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Quote:
Originally Posted by ghost_og

Not trying to pick a fight, but I just wanted to point out that what they say regarding battery stats isn't misleading. Batterystats.bin and "battery status" are not related. The battery stats that everyone wipes in CWM are exactly what the Android Engineer said they are, usage statistics for battery consumption by apps. (which always get wiped any time you reach a full charge) Batterystats.bin has no effect on what battery life is being shown.



The battery reporting over 100% in CM9 was a kernel issue (checkout this commit). If you browse through the entire file for that commit, you will see the battery % is also handled there (search for battery_state), and you will see it's tied to the battery reaching 4200mV.
-----------------------------------------------------------------------------
Other than that, thanks for trying to clarify the "horrible battery" problem people always seem to think they have. Yesterday I saw someone asking about battery life 20 minutes after Notorious updated Neutrino, lol.

haha yeah, i say that comment lol. I said it was misleading for that fact you stated above, but my point was to tell how people can fully recalibrate the battery first before considering roms have bad battery usage. Because people now thinks that android os has nothing to do with the bad battery.

Interesting for the ICS battery issue... i was able to get it to 99% and 100% when i do the above cycle though, no more > 100%. but it is good to see it has been worked on
25th February 2012, 03:34 AM   |  #5  
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Quote:
Originally Posted by ghost_og

Not trying to pick a fight, but I just wanted to point out that what they say regarding battery stats isn't misleading. Batterystats.bin and "battery status" are not related. The battery stats that everyone wipes in CWM are exactly what the Android Engineer said they are, usage statistics for battery consumption by apps. (which always get wiped any time you reach a full charge) Batterystats.bin has no effect on what battery life is being shown.



The battery reporting over 100% in CM9 was a kernel issue (checkout this commit). If you browse through the entire file for that commit, you will see the battery % reading is also handled there (search for battery_state), and you will see it's tied to the battery reaching 4200mV.
-----------------------------------------------------------------------------
Other than that, thanks for trying to clarify the "horrible battery" problem people always seem to think they have. Yesterday I saw someone asking about battery life 20 minutes after Notorious updated Neutrino, lol.

i try he method from the first post , and i feel mybattery is lasting longer than before i just let it die at 7:53 am from today , connect the wall charger, let charge full, because i donīt have CWM recovery , i used battery calibrator from the market to recalibrate my battery

at 8:32 pm from today with a lot of whats app facebook some games and call etc im on 70 %

thanks for the TIP !!!
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