This works with or without root.
Cell Standby is using a huge amount of juice on some GS6 phones.
Hello everyone yesterday I posted my stats and if it would fix, you can find that in my post history. I've been running my phone for over 4 hours and have ZERO mention of cell standby on my battery screen.
The fix was this:
1) turn off phone
2) hold volume up, home button, power button until it boots into recovery
3) wipe cache partition
5) turn ON advanced calling
Give it a day and a full charge.
I am on 18.5 hours with 3% left and almost 4 hours screen on time.
Cell standby significantly dropped drom 30% to 40% and 13 hours battery to
like 15% and 18 hours.