I’m a fan of battery-historian - a companion webapp that you throw bugreport.zip files at and it will visualize it - FP3 : No Deep Sleep -> Battery drain - #2 by tcecyk
For one, it can be some interval (sync, mail, app updates…) that wakes up the device too often and this will be visible, then there’s malfunction as in apps keeping wakelocks without reason, keeping the device from an efficient cpu doze.