Sorry for the late reply. When I first got my Note 4, I would easily expect 5-7 hours of SoT. Like most Android phones I have owned, that honeymoon period is short lived. I know batteries degrade over time but, for me at least, something doesn't add up. The problem seems to manifest quicker than you expect and despite replacing several batteries, it still persists. I have had similar issues as you have described; gets hot despite not doing anything too tasking, always drains quickly, sudden drops when it gets low. There are days now when I will get 2 hours of SoT, with the average being around 3 and a bit hours. My current Note 4 is a replacement model as my previous one got the eMMC bug, and I am confident this model is actually brand new and not a refurb but still get battery issues. I have tried ROMs, Xposed apps, tweaking and plain old stock - nothing works. My battery problems seem to be getting worse as Android evolves, convinced this has something to do with it.
On a side note, low and behold (despite my current N4 being less than a year old), after my two year contract ends - my phone starts exhibiting strange behaviour (like it's trying to tell me to upgrade
). Weird hangs, complete brain fart moments, very noticeable slow downs. Not sure why as the ROM I am using has usually been rock solid.