- Check if some apps are draining battery. Do not install cracked apps from 3rd party source.
- Wipe Cache from Recovery.
- Take backup & Factory Reset if you have not done it after Major OS update. There will be a great performance boost also after that as it clears out previous OS's chunks.
- Maintain healthy battery charging cycle between 20 to 80% (never drain to 0). That so-called "battery calibration" is not required these days for Li-ion batteries.
