Weird or wrong remaining battery calculations

[Angelsnecropolis]

Here's the situation: Left phone plugged in to charge overnight. Woke up and unplugged. Phone is fully charged. 2 hours later I notice my phone is running hot even tho I'm not running any heavy apps nor do I have it plugged in. It's just locked and in my shirt pocket. Its at about 90% after 2 hours. I turn the phone off and back on and then it says my battery level is at 47%.

This has happened quite a few times. At one point I recalled it said I had over 40% left but when I restarted it was at 8%.

Is this some sort of software glitch in the GS2?

Sent from my Samsung Galaxy S II

 

[Baroka]

Have no idea what glitch or bug causes this but have experienced it on a number of times as well.
Seems rebooting the phone at times leads to a significant battery drain.

Sent from my SAMSUNG-SGH-I777 using Tapatalk

 

[konazxiii]

It has hit me as well. I flash ROMs somewhat regularly and not all of them do it.



This charge goes up after I pulled the USB off the charger-

 

[Docjeep]

I've seen postings that say there is a known bug in the battery software such that a reboot when the battery is below 50% causes the monitor to whack out (as evidenced by the battery increasing in charge in some cases). I've seen it myself.

As to the phone getting hot on you doing nothing, have you looked at your data useage. I woke up one morning and had a similiar experience. I noticed data was constantly running even though I wasn't doing anything. Tried switching wifi off, reboot, nothing worked. Battery monitor showed the email app running so I shutdown, pulled battery, and restarted and it worked fine. Haven't had it happen since.

 

[Entropy]

Nothing to do with software - it's a small corner case where the hardware fails to properly estimate battery. Getting faked out when rebooting on low battery is the small price we pay for never having to perform any sort of battery calibration shenanigans - the fuel gauge always converges towards truth over time instead of diverging, it just doesn't handle resets well.

You didn't magically lose 30-40% of your battery - the fuel gauge just thinks it is lower than it really is.

To avoid this, don't reboot on low battery, or reboot when on a charger. Or just wait after rebooting, it'll converge towards normal after a few hours.