Battery dropped 20% overnight. How can I find out what's causing it without rooting?

Nothing in the battery stats is abnormal and the phone didn't wake up a lot yet I lost a ton of battery overnight. How do I find what caused it? Also is their anyway to tell if I have a defective battery? A lot of people here and at /r/motox seem to be getting better battery life. I can barely get 3 hours of sot over 10 or so hours. I really want to keep this phone but if this is going to be normal then I might as well go back to the Note 4.




Sent from my Nexus 9 using Tapatalk