Hi fahimbhuyangb,
Please tell us your firmware version, and what is the battery level and variation?
Do you feel like battery drain after using the phone or in stand by without using it?
If while using the phone, does battery drain while using any specific apps?
Please tell me the app and the battery variation while using it for some time (e.g. 1 hr).
If there are battery drain issues in sleep mode,
in order for us to verify, please kindly follow the steps below and show us the screenshots.
1) Charge the phone to 100% before going to bed > remove the charger > Clear all apps in recent app list > turn off screen > the next morning before using the phone, please screenshot the two pages:
a) Settings > Battery
b) Settings > Battery > ""Advanced battery usage"" (tap the battery icon to access)
2) Tell me the battery variation: for example 23:00 (100%) > 08:00 (90%)
3) In the meantime, were mobile network, WiFi, and Bluetooth turned on or off?
Thank you.