I tried this method...

1.Charged tab t0 80%, then shut down (removed charger) for 1 hour.
2.Turned on tab and played games for about 45min till battery was 49%.
3.Turned off tab and let sleep for 5 hours (charger still removed).
4.Turned tab back on and battery reads 79%, used for about 20min and battery reads 68%... Seems battery drain is still happening?

Right now i'm charging the tablet back upto 100% then perhaps try this method again... Did I do something wrong?

Originally Posted by jzen

I tried this method...

1.Charged tab t0 80%, then shut down (removed charger) for 1 hour.
2.Turned on tab and played games for about 45min till battery was 49%.
3.Turned off tab and let sleep for 5 hours (charger still removed).
4.Turned tab back on and battery reads 79%, used for about 20min and battery reads 68%... Seems battery drain is still happening?

Right now i'm charging the tablet back upto 100% then perhaps try this method again... Did I do something wrong?

same problem im facing. This is why im wondering is the 40% value of before or after calibration. Because although it might drop 40% before calibration is done, the real drop value might be less then that. Which means to the chip it might just see a drop of example 20% of real drop and hence it didn't perform the calibration because conditions of 40% is nt met.

I did forget to flash back to the stock kernel (using pershoot's).

I just flashed to doc's slim 6.5 which has a modified stock kernel (couldnt find just the stock kernel and my internet is too slow to download the entire stock rom.). Going to try this method again but starting at 40%

1.Battery at 40%, shutdown tablet for 1 hour.
2.Charge tablet to 100% (while shutdown)
3.Leave tablet shutdown for 5 hours
4.Pray to droid gods, find my rain stick and begin dark resurrection ritual while watching true blood.

My only question now is... Should I turn the tablet back on after the 1 hour shutdown? Or should I leave it shutdown and just plug in charger till its 100% charged, then let it stay shutdown for 5 hours?

This is what worked for me:

1. Charged tab to 100% removed from charger.
2. Power down for 1 hour.
3. Power on (tab at 96%)
4. Drain to 46%
5. Power off for 5 hours

When I powered the tab back on after the 5 hours, i used it for a while and rebooted and the battery reading stayed the same which it wasn't doing before the calibration. It has been draining and charging at a normal pace since then and has remained the same after reboots and ROM flashes since the calibration.

Originally Posted by FillTheVoid

This is what worked for me:

1. Charged tab to 100% removed from charger.
2. Power down for 1 hour.
3. Power on (tab at 96%)
4. Drain to 46%
5. Power off for 5 hours

When I powered the tab back on after the 5 hours, i used it for a while and rebooted and the battery reading stayed the same which it wasn't doing before the calibration. It has been draining and charging at a normal pace since then and has remained the same after reboots and ROM flashes since the calibration.

I'm going to go ahead and try this method right now! But for me... sometimes my battery will not charge unless the unit is shutdown (ever since battery issues started.). I hope this time it will charge while its on.


Also the instructions say to flash the stock kernel before trying this method... Did you do this? And were you able to flash back to pershoot's without issue?

*Update:
It doesn't look like its charging, (system on). Should I just shutdown and charge it to 100%? Then continue with said method? Anyone know if this method will work while tablet is shutdown through the entire process?

Originally Posted by jzen

I'm going to go ahead and try this method right now! But for me... sometimes my battery will not charge unless the unit is shutdown (ever since battery issues started.). I hope this time it will charge while its on.


Also the instructions say to flash the stock kernel before trying this method... Did you do this? And were you able to flash back to pershoot's without issue?

My tab was charging while on, sometimes it wouldn't show it till after a reboot. I did mine from stock 3.1. (A backup I made before I took the TW OTA) I have not re-flashed pershoot's kernel and probably wont till the bug is worked out. I did however flash the deodexed stock TW and flashed a theme and have had no issues.

Edit: if its not chargin while on, i would charge it all the way while off then turn it on so it can read the battery then start the 1 hour power down.

Correction guys...

I was sure that our p7510 model was using TI bq20z75 fuel gauge chip but with new information looks like it's Maxim 17042 chip... It's embarrassing but I have to stay corrected. TI chip would calibrate itself in procedure outlined above as for Maxim - I don't know yet. I'm looking at it.

These are good and bad news. Good one - with this new fact, it's very possible that the reason of chip's SOC counter corruption is in software. Driver for Maxim is pretty messy and complex (because it's messy). In contrast driver for TI is simple and straight forward (because TI chip is smart). Software can be fixed but problem in hardware design not so easy.

Well, I will report back when I find something.

So, will FillTheVoid 's method work with my GT-p7510? :x

Originally Posted by Vlad_z

Correction guys...

I was sure that our p7510 model was using TI bq20z75 fuel gauge chip but with new information looks like it's Maxim 17042 chip... It's embarrassing but I have to stay corrected. TI chip would calibrate itself in procedure outlined above as for Maxim - I don't know yet. I'm looking at it.

These are good and bad news. Good one - with this new fact, it's very possible that the reason of chip's SOC counter corruption is in software. Driver for Maxim is pretty messy and complex (because it's messy). In contrast driver for TI is simple and straight forward (because TI chip is smart). Software can be fixed but problem in hardware design not so easy.

Well, I will report back when I find something.

A lot of this is way over my head, but my battery calibration seems to be accurate, although I can't be absolutely sure because I have no stats from the previous calibration to compare it to. I do know for sure that after this process the bug of it draining then after reboot going back to what it should be is gone.

so i guess we need to flash back the stock ROM w/o TW for this procedure to work? I was trying the same steps with StarBurst + pershoot kernel it seem that it doesn't work. Anyone manage to calibrate with pershoot kernel?