30-40% battery drain at night I am using unlocked Samsung Galaxy S5 G900F model for 1 year.
It working fine. But for 3-4 months I cannot keep my phone on overnight.
It drains battery to 30%-40%. I have tried all possible solution like:


kept brightness to minimum
WiFi, mobile data, Bluetooth, GPS kept off
stopped unwanted services like FB, S finder, etc from App manager.


I mean all possible options.

It shows that Phone radio and network are draining my batter (as shown in attached images)
Also how can screen brightness drain battery when kept idle screen locked mode overnight? (as shown in attached images)
Please Help.
I have attached screenshots when I found 69% battery remaining in the morning (kept at 100% at night)

Note: 


During day battery performs normally even with WiFi and data
Even when kept in ultra power saving mode overnight it drains around 20% battery








Screenshots - Battery Info(Click to enlarge images)
That's a known bug in android where there is no real solution for, you live in a zone with bad reception or just in between antennas.
Possible solution are: moving. Or, set your phone to 2G networks only, certainly at night. I ALWAYS put my phone on flightmode at night...

if you are rooted you can use an app for that: 2G 3G 4G switch

I read the bug is even still there in the current beta version of Android M (6.0).
I had the problem for a while but then it suddenly went away... maybe antenna transmission had slightly changed by my provider.