So far I have come to the following conclusions
1) Draining the battery to 0% and charge back up doesn't have any effect. It may help to calibrate the reporting.
2) Hard resetting the phone has no effect. It may help to calibrate the reporting.
3) The only sure way to reduce battery drain
- Disable Blue-tooth while not in use
- Disable NFC while not in use
- Change brightness from automatic to Low
- Block background tasks of apps you don't use frequently. Nokai Drive+ BETA may have some issues as its still in BETA so it makes sense to block this for now.
- Turn of battery saver
4) You can further reduce drain by doing the following but you lose some functionality
- Set e-mails to sync manualy
- Turn off location service
- Turn off Wi-Fi
- Turn off Data Roaming
- Turn off find my phone
Calibration should settle after week or so, but don't let the phone drain down to 0% as it will have to re-calibrate itself. If you still have abnormal battery drain, then hard reset and remove all 3rd party apps and monitor. If the problem persists then very likely faulty battery/phone get a replacement.