OS Error

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My Samsung tab 2 7.0 brought up an "error with the OS" message after accidentally did a soft shut down. Now the battery is just draining very fast. I had first thought it was because of the new case I got that has magnets in it, but ive learned that the affect is negligable. Will a calibration take care of this issue with draining? any help is appreciated.

Lance

Just for information, calibration didn't work for me so I decided to go hard and open up the housing. It is quite easy, when you have some old plastic credit card (start from the shorter side and continue towards the bottom side with the socket). Disconnected the batter for like 5 minutes and it seems to be working now correctly. For the scarred ones - there is no warranty seal so you won't void it.

awesome

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Originally Posted by Vlad_z

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://forum.xda-developers.com/show...1&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.

Awesome - had updated to ics and battery was draining overnight. tab now working fine. This post needs to be a sticky.

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

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Hi guys,
I install A1 kernel on my cm10 and got batt bug. So I flashed back the original kernel and followed the instruction on page one and get rid of the bug. My tab is back to normal again. Question still remain, if i could still use A1 kernel, will it give me the batt problem again? In other words, can we still use the kernel that give the batt problem after caliberation?

Thanks Vlad_z for his contribution on this problem.

Sent from my GT-P7300 using xda premium

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

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It's a panacea effect.. Deleting the .stat file does nothing useful for battery drain.
Allow the battery to fully discharge and auto shutdown. Recharge 50%. Deplete to warning.
Fully recharge 100%. Stat file will gauge appropriately by third round recharge.

Sent from my SCH-I905 using xda app-developers app