So received my shiny new Nexus 5 yesterday (via RMA due to my battery issues). I decided not to setup Google Now on it. Ensured screen brightness was down at the 20% or so mark. Switched GPS location thingy to "battery optimized", turned off scanning always available on Wifi. Then proceeded to simply install my email accounts (about 5 of them), and NO other apps. No Facebook which I never use, no LinkedIn which I always use, no Twitter which I sometimes use, no BeWeather which I used to use as a widget, no Sportsnet which I used to use as a widget, no games, nada. Well, that's not true, I did install Evernote. I also left Bluetooth on and Wifi on (since Google actually recommends leaving Wifi on to "Save" batter power).
Process took about an hour or so, drained the battery to around 40%. Charged it to 80% or so before leaving to go home. By the time I went to sleep at 10pm it was at 54%. Woke up around 5am, checked the phone, it was at 36%. Got up a short while after that, checked a few email (received about 20 over night, most of which were deleted).
By the time I drove in to work at 7am, I was at 28%.
Biggest consumer was "Google Play Services", though I think this is because it was updating several apps for that hour before I charged it to 80%?
My favorite part of this whole mess of a phone is that one of Google's recommendations is to "put the phone in airplane mode" when either I'm not expecting to use it or when the signal appears low. Brilliant idea Google. Maybe I can start to anticipate when I'll receive phone calls and emails, or tweets, or linkedIn messages, and only turn on the phone at that point in time.
I'm starting to wonder if at this point it is an issue with the Bell network in Toronto and how the Nexus 5 interacts with it?
Edit: BTW, I also cycled the power before going to sleep. Just in case.