Nexus 5 whole battery drained in a single night I charged my phone to 100% before going to sleep. I used it for only few minutes and found out my phone was off in the morning because all the battery was drained. I charged it and saw battery stat and it showed as:



It shows that the screen was totally off the whole night. What caused the battery to drain so fast?

Another stat view:



It is the first time this has happened.
We are using Exchange on serveral devices at the office (for testing) and what i noticed is that sometimes exchange services seem to drain alot of battery even when set to a low interval or push. 

This typically happens when Exchange is trying to pull some data from the server but an error occurs. The end user (you) does not always see the error. 

For me usually a reboot fixes the problem, worst case remove the Exchange profile and reinstall it afterwards.