Have you considered it can be a bug related to the GSAM app? Sorry for digging out the thread, but it has happened to me since I bought my S6.
I say that because I actually still have a somewhat decent battery life.
I have absolutely no .mp3 or video files in my device. All google settings that...
I guess you tried to flash TWRP directly from Odin, right? It happened to me.
Try searching for CF Autoroot in Google. It worked for me.
Otherwise, search XDA Forums for Arter97's recovery (it's nothing but a working 3.0.0 TWRP).
Weird what is happening here.
I do heavy usage (power gaming) while charging and have no burnings at all. Of course it does get hot, but nothing unbearable or hazardous.
I always do that in my S6. Never let both Wi-Fi and Cellular Data on together and still have a huge "Cell Standby" drain.
I'm using S6 International version (I'm from Brazil) which does not even have Advanced/HD Calling, VoLTE or Wi-Fi Calling features (maybe they're deeply enabled somewhere in...
I can confirm this also in H818P (Dual sim version) running V10c with TIM brazilian carrier. It must be an international issue. Something must be done. Only con I found in this phone so far.