I've started experiencing bad battery drain on My S6.
The last time I had to diagnose battery drain was long time ago on an LG G2 that I'd rooted. It had a really good battery diagnostics showing usage by hardware as well as services etc IIRC.
But my S6 (with latest updates) gives very little information - and it seems incomplete. Over night my battery went down from near 100% to completely dead, but the battery usage screen showed just 13% usage by the screen, and 6 apps / services using a total of 7% between them, so total percentage being under 20%! What about the other 80%? I don't trust the results at all.
I've tried various battery usage apps and they all just direct the user back to Samsung's battery usage screen.
What can I do to get a hold on what's all of a sudden causing this battery drain? I've done reading online and what's suggested is very hit and miss. I don't want to spend hours or even days playing the guessing game and having to experiment to find the problem!!!