I used the phone last night from fully charged it dropped to 88% with half an hour of screen on, then it wan't placed on the charging pad correctly and this morning after 6 1/2 hours off charge it was on 64%, 20% overnight at idle..
my stock N5 will loose may be
5% battery overnight. Something is wrong with your phone or apps. I don't use battery saving apps but I force kill some startup services to keep it clean (and hit the EScleaner widget several times a day)
Nexus N5 stock, not even rooted
Atrix HD LTE with EB40 battery mod, and Lapdock