For tabs with battery drainage problem... or how to calibrate

Search This thread

pellegj

Senior Member
May 18, 2011
73
7
I have this as well on my 7500. I had fully charged before i got to bed last night and turned it off. This morning i ran it down to 19% and turned it off for 5,5 hours. Guess my surprise when i turned it on again and it said 64% remaining. I have tried all afternoon now, and every time it says it's under 15% i turn it off for 5 minutes and turn it back on, and it's back up to a bit over 50%, and draining fast. I'm gonna try to drain the battery as much as possible and then turn it off for an hour, charge it over night and turn it off for 5 hours and see what happens.
 

jzen

Senior Member
Oct 9, 2010
720
254
I have this as well on my 7500. I had fully charged before i got to bed last night and turned it off. This morning i ran it down to 19% and turned it off for 5,5 hours. Guess my surprise when i turned it on again and it said 64% remaining. I have tried all afternoon now, and every time it says it's under 15% i turn it off for 5 minutes and turn it back on, and it's back up to a bit over 50%, and draining fast. I'm gonna try to drain the battery as much as possible and then turn it off for an hour, charge it over night and turn it off for 5 hours and see what happens.

Did this happen to you after you installed Pershoot's kernel? I just want to find out if it was something in the kernel that caused the battery drain issue, in my case I'm pretty sure it was the kernel... As of right now my tablet is sleeping for 3 more hours before i can check it out and see if it worked...

I have Doc's slim 6.5 installed with his modified stock kernel... It took 2.5 hours to drain down to 40% (full brightness, 1ghz, all options set on, GPS,WIFI,ect...) Does this sound normal? If so It may have just fixed itself after flashing stock 3.1 rom then doc's slim ontop of it... Thanks all for your support <3
 

FillTheVoid

Senior Member
Mar 10, 2011
255
54
It happened to me after installing pershoots kernel. I noticed it right after I used the set on boot feature of Setcpu to overclock on start up.
 
  • Like
Reactions: jzen

wlighter

Senior Member
Aug 9, 2011
233
26
I have the same setup as FillTheVoid. perhoots kernel oc at bootup. I never try to uncheck this option previously, so i dont know if this option cause the issue. Anyway i doubt it will make a difference now since the fuel gauge is all screwed up.
 

pellegj

Senior Member
May 18, 2011
73
7
Did this happen to you after you installed Pershoot's kernel? I just want to find out if it was something in the kernel that caused the battery drain issue, in my case I'm pretty sure it was the kernel... As of right now my tablet is sleeping for 3 more hours before i can check it out and see if it worked...

I have Doc's slim 6.5 installed with his modified stock kernel... It took 2.5 hours to drain down to 40% (full brightness, 1ghz, all options set on, GPS,WIFI,ect...) Does this sound normal? If so It may have just fixed itself after flashing stock 3.1 rom then doc's slim ontop of it... Thanks all for your support <3

Yes and No actually.
I had pershoot's kernel installed when it started, running secretfile's rom (installed the kernel right away after installing the rom, just booted the rom once, then rebooted to cwm and glashed the kernel). However, I've been running pershoot's 8/9 kernel on stock rom before it started without any problem. So, for me it started in combination of secretfile's rom and pershoots kernel, but i can't say which of it caused the problem.
I now fully charged it over night and wiped battery stats first thing this morning, gonna let it run and see how it goes. I'll back to report later.
 

FillTheVoid

Senior Member
Mar 10, 2011
255
54
My previous posted method of calibration (what the op says) did in fact stop the battery from super draining then going back up after reboot. I can't say for sure if the battery is completely back to normal, I have nothing to compare it to but as far as I can tell I'm running normal again.
 

wlighter

Senior Member
Aug 9, 2011
233
26
My previous posted method of calibration (what the op says) did in fact stop the battery from super draining then going back up after reboot. I can't say for sure if the battery is completely back to normal, I have nothing to compare it to but as far as I can tell I'm running normal again.

you should be looking about 10% per hour battery usage for normal browsing on wifi
 

wlighter

Senior Member
Aug 9, 2011
233
26
Yes and No actually.
I had pershoot's kernel installed when it started, running secretfile's rom (installed the kernel right away after installing the rom, just booted the rom once, then rebooted to cwm and glashed the kernel). However, I've been running pershoot's 8/9 kernel on stock rom before it started without any problem. So, for me it started in combination of secretfile's rom and pershoots kernel, but i can't say which of it caused the problem.
I now fully charged it over night and wiped battery stats first thing this morning, gonna let it run and see how it goes. I'll back to report later.

this is stock rom with our without TWUX?
 

wlighter

Senior Member
Aug 9, 2011
233
26
Ok, I manage to get the battery calibration to work finally. I verify it by using it for a while (let it drop 5%-10%), record down the battery %, restart, and check the battery % again. If its the same means its solve.

The following steps work for me:

1. Drain down to below 40% (value after reboot; i believe this is the real value) the fake value can be anywhere... so i wont quote that.
2. Turn off for 1 hour
3. Turn on and charge to 100%
4. Turn off for 5 hours

This is with pershoots kernel, disable apply on boot in setcpu.

If set to 1.4Ghz my usage is about 3 minute for every 1% of battery. Which is about 20% per hour of usage.

If set to 1Ghz my usage jump to 6 minute for every 1% of battery. Which is about 10% per hour of usage. Which is what is expected base on the stock rom.

I will report more if i found anything.
 
  • Like
Reactions: jzen

pellegj

Senior Member
May 18, 2011
73
7
I been playing Tower Raiders 2 now for about 2 hours after fully charged and wiped battery stats, still at 77% remaining, looking good so far.
 

pellegj

Senior Member
May 18, 2011
73
7
I been playing Tower Raiders 2 now for about 2 hours after fully charged and wiped battery stats, still at 77% remaining, looking good so far.

Update!
Been 8,5 hours since i took it off the charger. It's been used for 7,5 of that, about 4,5 hours of playing, and transferring about 10GB over WIFI. BT has been on all the time and screen have been on for 7,5 hours. 17% left, and i also tried shutting it down and starting it up again, it still said 17%. So i guess/hope my problems are gone for now.
Gonna let run out of juice and then charge it again and try with pershoots kernel once more.
 

jzen

Senior Member
Oct 9, 2010
720
254
Well...

1.Flashed stock 3.1 rom
2.Flashed doc's slim 6.5 rom
3.charged to 100%
4.flashed pershoot's 1.4ghz kernel

After these steps my tablet is back to normal and runing smoother than ever! Getting great battery life now about 5%-10% per hour drain depending on wifi switch. Been gaming, emailing and browsing for the last 2 hours and only down to 85% :D!

Update: Pershoot just release his reworked kernel, downloading it right now, will flash and then I will report back!
 
Last edited:

wlighter

Senior Member
Aug 9, 2011
233
26
Well...

1.Flashed stock 3.1 rom
2.Flashed doc's slim 6.5 rom
3.charged to 100%
4.flashed pershoot's 1.4ghz kernel

After these steps my tablet is back to normal and runing smoother than ever! Getting great battery life now about 5%-10% per hour drain depending on wifi switch. Been gaming, emailing and browsing for the last 2 hours and only down to 85% :D!

Update: Pershoot just release his reworked kernel, downloading it right now, will flash and then I will report back!

u running on 1.4ghz on demand?
 

jfcooley

Senior Member
Jul 15, 2011
638
193
Charlottesville Va
I dont post much, but ive tried everything in this thread and cant fix this issue. It was fine until i rooted and flashed a ROM.

Frustrated beyond belief.
 

ivarson_swe

Senior Member
Oct 17, 2009
165
17
This trick helped me too. Looking at 10% drop an hour. My only concern is that my p7500 drops from 100 to 99 percent as soon as I pull the the charger. How long does your devices keep showing full charge?
 

Vlad_z

Senior Member
Mar 25, 2011
506
178
This trick helped me too. Looking at 10% drop an hour. My only concern is that my p7500 drops from 100 to 99 percent as soon as I pull the the charger. How long does your devices keep showing full charge?

dropping from 100 to 99 the moment you disconnect charger is fine.

With moderate brightness 10-20% you looking for 10-14% charge consumption per hour.
 
  • Like
Reactions: ivarson_swe

jzen

Senior Member
Oct 9, 2010
720
254
Yep once I unplug my tab its at 99% and stays that way all day unless I use it. sometimes even after listing to music on my break (hour) its still at 99% (screen off of course).

Last night I flashed Pershoot's new reworked kernel, I have it running ondemand 215mhz - 1.4ghz, when screens off it runs at 215mhz, using set on boot also with no issues thus far.

After 8 hours being idle, 1 hour of music listing, 20 min playing dead space, recording 720p video for a half hour and playing with movie maker for another half hour I still have 75% battery left over :D not too shabby!
 

Top Liked Posts

  • There are no posts matching your filters.
  • 19
    I've got this problem with my tab (quick battery drainage). Symptoms would be your 100% charged tab would go down to 0% in unusual shorter time ( like 2-4 hours). You put it on charger and tab would be charged back to 100% again in substantial short time like 2-3 hours instead of 6-7 hours.

    Well, after looking at this issue I think I have come up with solution.
    At least, my tab looks like it's back on track... though, to say for sure I would need another couple days of testing.

    The problem is not runaway wild application on a background but battery control circuit. This chip reports to OS much smaller battery capacity as it is for some reason. I will not go into details but here is what you need to try:

    Flash stock kernel (may be custom kernel is not the reason for bad chip calibration and I'm 90% positive but just to be on safe side). You don't need to do factory wipe in OEM recovery for our purpose.

    You also don't need to wipe batterystats.bin or use "Battery Calibration" apps from market (which does exactly the same wipe just in more end user friendly way). This wipe serves no other purpose then refreshing your usage statistics.

    You also don't need to drain your battery all way down... nice, this way you don't have to wait for too long.

    Well, here we go:

    charge tab somewhere in between 80 and 100%.
    edit: remove charger
    shutdown tab (not put in hibernate/sleep) for 1 hour.
    edit: turn tab on and run it for 30-40 min. or whatever it takes to drop charge to 40-50%.
    shutdown tab again for 5 hours (overnight).

    turn tab again and check... you should be fine now, charge it again 100% and use as usual.

    That should do correct chip calibration.


    PS: the reason why this chip calibration went bad at the first still remains open.



    EDIT: just want to give a shortcut for those who does not feel like reading through the thread.

    http://xdaforums.com/showpost.php?p=16771651&postcount=41

    Edit: here is calibration procedure which was modified down this thread ...

    1. in CWM/recovery let it sit till battery in terminal will show less then 3700. The less you can get it the better. 3400 is probably absolute minimum.

    2. shut down tab and let it sit for 1 hour.

    3. plug it to charger and charge it for 5 hours.

    4. disconnected charger and let it sit for 1 hour.

    5. boot up your tab and test it, it your battery still not calibrated you can flash back your backup and repeat calibration procedure.

    Edit: if you physically disconnect battery (you have to disassemble tablet) and keep it for couple min. that would trigger FG chip to start with default SOC curve.
    17
    I want to give you guys updates on my findings regarding fuel gauge chip Samsung is using in our tabs.

    It's MAX17042. I spend lots of time looking for datasheet but cannot find it. I found some very similar chip but still not exact. It looks like this chip was specially designed for Samsung by Maxim. So any further knowledge was derived from looking at various drivers for different Samsung devices.

    Ok, looks like max17042 is utilizing combination of coulomb-counter with impedance tracking algorithm. What does it practically mean?

    There is "quick start"/"quick charge estimate" software function but it's not accessible without special cable or kernel software change. If someone wants to try this I can elaborate on that more.

    What can we do without any special thingy?

    Tab needs to be at rest (turned off) for at least an hour when its empty and then when it charged back. This will let chip to make 2 open circuit voltage measurements.

    How to make sure that tab is discharged enough for calibration to take the place? If capacity is off big time then gauge may report SOC 30% but in the fact battery is in 70%, so chip will not execute calibration procedure.

    The most sure way to check this is in terminal, execute this command:

    cat /sys/class/power_supply/battery/voltage_now

    or through adb:

    adb shell cat /sys/class/power_supply/battery/voltage_now

    your good discharged start point should be anything below 3700 (3.7V). If your tab is telling that you have 0% capacity but voltage is more then 3700 then keep rebooting tab (this will refresh counter for a moment) or just boot in CWM and let tab run/sit there for some time.

    Then charge it with power adapter to 100%, you can check voltage at this point - should be around 4100, usually you should be good.

    Then shutdown tab for another hour or two.

    That's it. You should be good now unless you are still using certain custom kernels.


    PS: I have heard cases when SOC miscalculation occurred on totally stock devices, well, I have no explanation for that, but with custom kernels which allow to charge through USB cable - there is a code path to write wrong data into remaining capacity counter stored in the fuel gauge chip.

    After it happens and even when you are back on stock kernel then it will take some time for the chip to slowly correct itself or you need to force recalibration outlined above.

    Btw, resent custom kernel (from pershoot) does not include charging by USB functionality. Well, there is nothing wrong with that idea. It just Samsung implementation of charging algorithm is not good if such function will be allowed.
    3
    I agree. The problem is the devs refuse to to add a disclaimer of the issues. Im sure if some of the people in this thread knew flashing other kernels and ROMs would cause this battery damage (which it does as statistics dont lie) they wouldnt do it.

    If you can do anything to help protect people from this issue it would be to state a clear disclaimer of this issue in all aftermarket kernel and ROM threads. Why is this not being done? :confused: You cant argue with the dozens of people here who have gotten this issue after they flashed ROM/ kernel.

    Be aware that I know you may not value me or my tablet but I ask for you to value others as they spent their hard working money on these tablets and it hurts me to see their units become crippled like this.

    exactly. you spend your money, and we make it multiply overnight. we do things the manufacturer wouldn't dream of doing (sometimes), and/or did not implement. you get to see development right before your eyes and be a part of something great in the making. for example, if i didnt value everyone's tabs, i wouldn't work so dilligently to perfect things across numerous devices. if i didn't care to make said device great (to the best of my ability), i wouldn't post anything. i like to share and have everyone reap the benefits.

    you are not protecting anyone by alienating yourself, in the way that has been done, thus far. this makes your core statement/focus lose credibility by the tenfold.

    here is a better way to phrase something:
    hey. im receiving xx issue. any logs or something i can get for you to try and rectify the issue?

    that would help a ton of people.
    2
    May I ask what do you mean by rest time intervals of 1 and 5 hours?

    Does it mean that the calibration will only take place when the tab is off for 1 hour, then switch on and used till battery depleted by a further 40% minimum and the switch off for another 5 hour. Correct?

    Also , is this 40% refer to value before or after calibration? I asked this because when I restart my tab the value changed (ex: 36% before restart to 53% after restart)

    Yes that's correct.

    Fuel gauge chip will take 1 measurement of open circuit voltage and internal resistance only when battery is at rest (no charge/discharge) for at least 40min. - so I say 1 hour just to be sure...

    Consecutive measurements, from which gauge chip can derive capacity of the battery have to be at least 40% and 5 hours apart.

    Technically speaking, that 40% difference can be in either directions. Say you have 40% as of now, leave it in rest for 1 hour, then charge it to 100% and leave it at rest for 5 hours and you will have same result.

    Condition "at rest" means voltage change less then 4mV (or mkV) per sec. - I don't remember.

    When tablet is in sleep some background processes may awake tablet briefly and reset the 1 hour counter - so to make it work for sure, simply do shutdown.

    if you want additional reading on my findings then look here:

    http://xdaforums.com/showpost.php?p=16615800&postcount=517
    2
    My previous posted method of calibration (what the op says) did in fact stop the battery from super draining then going back up after reboot. I can't say for sure if the battery is completely back to normal, I have nothing to compare it to but as far as I can tell I'm running normal again.

    you should be looking about 10% per hour battery usage for normal browsing on wifi