Attend XDA's Second Annual Developer Conference, XDA:DevCon 2014!
5,736,958 Members 51,868 Now Online
XDA Developers Android and Mobile Development Forum

[TWEAK] SGT 7.7 Battery Calibration [Fuel Gauge Reset]

Tip us?
 
UpInTheAir
Old
(Last edited by UpInTheAir; 23rd August 2013 at 02:10 AM.) Reason: added info
#1  
Recognized Contributor - OP
Thanks Meter 4516
Posts: 4,187
Join Date: Jan 2011
Location: Phuket, Thailand
Battery Full [TWEAK] SGT 7.7 Battery Calibration [Fuel Gauge Reset]

Samsung Galaxy Tab 7.7 Battery Calibration [Fuel Gauge Reset]


If you are having incorrect battery SCALING issues, this will reset your device battery % to scale correctly to the available mV.

After flashing kernels and ROMs 100's (possibly 1000) of times on this device, I had an issue where my tab would not display 'actual/real' battery percentage correctly.

My tab would discharge to approx 30-35% then drop to around 10-11% almost instantaneously, sometimes shutting off if I wasn't paying close attention !

Similar to the SGS2, resetting battery stats doesn't work and nothing to do with it anyway, it just resets the reporting in device settings/battery. Battery % reporting calibration didn't help either.

There are apps available for SGS2 to reset the fuel gauge, but don't actually work for our device because of the file name & location is different. Also, the SGS2 has the advantage of being able to remove the battery (easily) and leaving out for approx 180 sec, apparently giving the same affect of reset.

I got he idea from this thread : Questions about "Fuel-Gauge chip" and how it works & recognised developer entropy512. After some digging during my SkyHigh kernel development, I found the correct directory for my device and gave it a try........


DISCLAIMER : The below reset method has been successfully tested on my P6810 ICS 4.0.4 running SkyHigh kernel ! MAY NOT WORK FOR YOU, so NANDROID first !


REQUIREMENTS :

1. SGT 7.7
2. Rooted firmware and SuperSU / Superuser app installed
3. Android Terminal Emulator app installed & granted SU access
4. Existing directory : /sys/class/power_supply/battery/fg_reset_cap


FUEL GAUGE CHIP RESET & BATTERY % "REPORTING" CALIBRATION

Method :

1. Open Android Terminal Emulator app
2. Type & enter
Code:
Select Code
su
echo "1" > /sys/class/power_supply/battery/fg_reset_cap
 


3. Reboot device
4. Battery % "reporting" calibration (digital)
a) Deplete battery to 5-10% (NOT ZERO)
b) Charge UNINTERUPTED until FULL (don't touch)
c) Unplug and then use normally. Device should then re-calibrate itself
5. Repeat Step 4 (ONLY IF NEEDED)



RESEARCH NOTES & RECOMMENDATIONS

* Carry out Step 4 once in every 30 charge cycles to keep Battery % "reporting" (digital) calibrated

* Continual deep discharge will shorten battery life

* Don't let the battery discharge completely : potential to damage the battery and/or the battery fall "asleep" (internal safety circuit opens) with the charger then unable to service the battery.



Screenshots below after fuel gauge reset. You can see the immediate drop from 87 -> 70% to align correctly with the approx available mV.

 






This obviously worked for me, no promises, but hopefully it helps some of you too. :thumbup:


.
THANKS costs nothing.......

N9005 HLTE : Developer of :
 
SkyHigh Kernels for SM-T700/705, SM-N9005 & SGT 7.7 : P6810 - P6800

SkyHigh JB ROMs for SGT 7.7

P6810 + kernel & P6800 (discontinued)

[TWEAK] SGT 7.7 Battery Calibration [Fuel Gauge Reset]

[Guide] Flash Official JB 4.1.2 Firmware on P6810 Wi-Fi Device

+ Many other guides, mods & contributions
The Following 10 Users Say Thank You to UpInTheAir For This Useful Post: [ Click to Expand ]
 
ZhenMing
Old
#2  
ZhenMing's Avatar
Senior Member
Thanks Meter 37
Posts: 295
Join Date: Feb 2008
Location: Penang
Good stuff
Current Phone:
- Nexus 5 rooted running OmniROM + Linaro r34t2

Standby Phone:
- Samsung Galaxy Tab 7.7 3G version (P6800) running OmniROM.

Fully retired Phone:
- Google Nexus One loaded with CM7.2 RC2
- Siemens S and SL series of phones.
The Following User Says Thank You to ZhenMing For This Useful Post: [ Click to Expand ]
 
UpInTheAir
Old
#3  
Recognized Contributor - OP
Thanks Meter 4516
Posts: 4,187
Join Date: Jan 2011
Location: Phuket, Thailand
Quote:
Originally Posted by ZhenMing View Post
Good stuff
Glad it helped

Sent from my GT-P6810 using xda premium
THANKS costs nothing.......

N9005 HLTE : Developer of :
 
SkyHigh Kernels for SM-T700/705, SM-N9005 & SGT 7.7 : P6810 - P6800

SkyHigh JB ROMs for SGT 7.7

P6810 + kernel & P6800 (discontinued)

[TWEAK] SGT 7.7 Battery Calibration [Fuel Gauge Reset]

[Guide] Flash Official JB 4.1.2 Firmware on P6810 Wi-Fi Device

+ Many other guides, mods & contributions
The Following User Says Thank You to UpInTheAir For This Useful Post: [ Click to Expand ]
 
staticinferno
Old
#4  
Junior Member
Thanks Meter 1
Posts: 13
Join Date: Aug 2011
May have to try this. I have noticed that I'm starting to see this more in my tab but I haven't flashed or kernel'd near that many times. I have been running cm9 for over a year now. I have been using the nema battery calibrate tool though.

It's good to know there is another step to try, I was about ready to order tools and an OEM battery and make a swap.

Sent from my GT-P6810 using XDA Premium 4 mobile app
 
UpInTheAir
Old
(Last edited by UpInTheAir; 21st September 2013 at 12:33 AM.)
#5  
Recognized Contributor - OP
Thanks Meter 4516
Posts: 4,187
Join Date: Jan 2011
Location: Phuket, Thailand
Quote:
Originally Posted by staticinferno View Post
May have to try this. I have noticed that I'm starting to see this more in my tab but I haven't flashed or kernel'd near that many times. I have been running cm9 for over a year now. I have been using the nema battery calibrate tool though.

It's good to know there is another step to try, I was about ready to order tools and an OEM battery and make a swap.

Sent from my GT-P6810 using XDA Premium 4 mobile
If your circumstances warrant it, yeah, give it a try.

Forget the app though (edit: are useless for our device), just follow the steps and hopefully you'll see a difference.

Sent from my GT-P6810 using XDA Premium 4 mobile app
THANKS costs nothing.......

N9005 HLTE : Developer of :
 
SkyHigh Kernels for SM-T700/705, SM-N9005 & SGT 7.7 : P6810 - P6800

SkyHigh JB ROMs for SGT 7.7

P6810 + kernel & P6800 (discontinued)

[TWEAK] SGT 7.7 Battery Calibration [Fuel Gauge Reset]

[Guide] Flash Official JB 4.1.2 Firmware on P6810 Wi-Fi Device

+ Many other guides, mods & contributions
 
UpInTheAir
Old
#6  
Recognized Contributor - OP
Thanks Meter 4516
Posts: 4,187
Join Date: Jan 2011
Location: Phuket, Thailand
Quote:
Originally Posted by staticinferno View Post
May have to try this. I have noticed that I'm starting to see this more in my tab but I haven't flashed or kernel'd near that many times. I have been running cm9 for over a year now. I have been using the nema battery calibrate tool though.

It's good to know there is another step to try, I was about ready to order tools and an OEM battery and make a swap.

Sent from my GT-P6810 using XDA Premium 4 mobile app
So how did you get on?

Sent from my GT-I9500 using XDA Premium 4 mobile app
THANKS costs nothing.......

N9005 HLTE : Developer of :
 
SkyHigh Kernels for SM-T700/705, SM-N9005 & SGT 7.7 : P6810 - P6800

SkyHigh JB ROMs for SGT 7.7

P6810 + kernel & P6800 (discontinued)

[TWEAK] SGT 7.7 Battery Calibration [Fuel Gauge Reset]

[Guide] Flash Official JB 4.1.2 Firmware on P6810 Wi-Fi Device

+ Many other guides, mods & contributions
The Following User Says Thank You to UpInTheAir For This Useful Post: [ Click to Expand ]
 
funny-dave
Old
#7  
Junior Member
Thanks Meter 2
Posts: 16
Join Date: Dec 2013
great work
 
Djgenes
Old
#8  
Member
Thanks Meter 2
Posts: 37
Join Date: Jul 2013
Hi. My phone is an Xperia P. On another thread I found the following code line:


Quote:
Knowing this the command line that "should" reset the chip is:

Code:
echo "1" /sys/class/power_supply/ab8500_fg

As you can see, without the > sign. and showing a different path. I wanted to know exactly how to perform it.
Could anyone help me, please?
The Following User Says Thank You to Djgenes For This Useful Post: [ Click to Expand ]
 
UpInTheAir
Old
#9  
Recognized Contributor - OP
Thanks Meter 4516
Posts: 4,187
Join Date: Jan 2011
Location: Phuket, Thailand
Quote:
Originally Posted by Djgenes View Post
Hi. My phone is an Xperia P. On another thread I found the following code line:





As you can see, without the > sign. and showing a different path. I wanted to know exactly how to perform it.
Could anyone help me, please?
As Post #1 states, you need to check your device has the directory/file you want to write to. Use a root type file explorer for that. I can't comment on your device, because this guide is for a SGT-7.7, but suggest to use the same format and method as in the guide. As always, nandroid first.

Best of luck.

Sent from my GT-P6800 using XDA Premium 4 mobile app
THANKS costs nothing.......

N9005 HLTE : Developer of :
 
SkyHigh Kernels for SM-T700/705, SM-N9005 & SGT 7.7 : P6810 - P6800

SkyHigh JB ROMs for SGT 7.7

P6810 + kernel & P6800 (discontinued)

[TWEAK] SGT 7.7 Battery Calibration [Fuel Gauge Reset]

[Guide] Flash Official JB 4.1.2 Firmware on P6810 Wi-Fi Device

+ Many other guides, mods & contributions
The Following User Says Thank You to UpInTheAir For This Useful Post: [ Click to Expand ]
 
riomilan
Old
#10  
riomilan's Avatar
Junior Member
Thanks Meter 4
Posts: 14
Join Date: Mar 2011
Great Tips
Very Helpfull, my battery tab need to calibrate

Tags
battery cal, fuel gauge reset, samsung galaxy tab battery cal, sgt 7.7 battery calibration
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes