Allow me one question, as I've been asking me every single time I read someone complaining about battery consumption during the night. Maybe I'm strange, but I use to charge my device while I'm asleep. What better time to charge is there, when you definitely are not going to use your device?
While thats true, that doesnt answer why the battery usage overnight is so poor...or for people like me who have pets that like to chew on wires, and since my phone is my alarm clock i need it next to me.
TC, I had the exact same problem...i even put battery saver ON for multiple nights only to still have the same about of battery drained over sleep. I believe this may be related to Live Folders or some other functions, i disabled Cortana but it didnt make a difference. Ive now reverted back to Prod Cyan/8.1 and my battery is back to normal (draining 3-5% over sleep).
Ive got a 1020, Rogers.
Pay attention to cell service wherever you leave your device at night. I've noticed that my LTE service is draining the battery much more since upgrading to Windows Phone 8.1 DP. Disabling LTE drastically improves battery life.
I don't have battery drain anymore after 2 weeks of using. Also, I kept using battery saver all the time with excluding apps I want to work in background. My usage is heavy but no games yet. I charge it once a day. I can use it for 2 days if I use the phone lightly but I can't. Try turning off wifi while sleeping.
That won't help much. I'm not sure who ever came up with this urban mystery that WiFi is a battery drainer. It's the opposite. Keeping WiFi off and completely relying on your cellular connection will drain your battery much faster than the other way round.
Lumia 625
Updated and my battery has drained much more than usual. Hopefully it will get better. I used to be able to turn off background tasks. However there does not seem to be an option to do that now???
Cheers.