Why is my battery charge draining fastly after I changed the display

Hey hi Ashik, I don't think that the problem is with the screen or something. It might be just a simple thing like screen brightness and all. If it is not, then just perform a factory reset and check if the battery problem is fixed. If not, then I would say that the problem directly blamed on the battery itself. BEWARE of the fact that if you have installed any other app and have given any background app permission or any other stuff like that, then it's not the battery but the app that is causing your phone to use more power.

Try closing background apps and limit there permission, also wait for a week before trying out a reset because there are many updates out there that sometimes just cause your battery to drain a lot faster, which eventually does get patched up later. Please wait for a week after closing and limiting permission of apps.

ALSO, check for your battery health, you can check that by using any professional app. Also, sometimes loose connection are also a major cause of fastery battery draining, see if your battery has proper and secure connection.

Thank you for reading and have a wonderful day Ashik =)