Extreme battery drain after marshmallow update

[bapmax]

I updated my G3 to Marshmallow four days ago and have noticed horrible battery drain. It seems to be from my screen as indicated by the battery usage percentage (very high, 67%). I've done a factory reset and keep my screen brightness at 5% or less to no avail. Any ideas? Please save my battery!

 

[belodion]

Welcome to the G3 forum.☺

Sometimes, system upgrades seem to cause battery problems, or trigger an impending fault....either that, or the upgrade and the battery problem are no more than coincidental. Does the battery get unduly hot with normal use of the phone?

 

[SeanM93]

I also have extreme battery drain, but my CPU overheats, too, making the power and volume buttons almost too hot to touch. Also, Marshmallow caused my phone to not be able to make calls: "Cannot make call", "Call was not made", "Service network not available", and "com.android.phone has stopped working" are now commonplace. About every 50th attempt to call will succeed, so 2% success rate with calling now. Talked to AT&T, they can't/won't help, talked to LG, they want my phone for 7-9 business days to re-flash it (20-minute process takes them nearly 2 weeks). Basically, nobody cares yet until we know just how many devices are being crippled in some form by the Marshmallow update.

 

[tonyvr4]

I had a similar problem with my LG G3 (AT&T D850) after the Marshmallow update. The battery time is less than before but it is not bad.

I was tinkering with the Qslide icons and noticed one that was labeled ""Battery Saver". Well, it turned out that this should be called battery waster. I turned this off and the battery time improved greatly.

 

[the Core]

In Settings > General > Battery > Battery Usage you can see how much of your battery your apps are using. Did you check that?

My G3's battery used to get hot too, so hot I feared to burn my fingers when touching the volume buttons. Also, my phone kept rebooting all the time.
This was the solution. Please try it too.