Loses charge fast when not in use and overheats when charging

Hey!

So my phone use to lose its charge fast when in use as well, however I replaced the battery and now it drains much slower. The battery would overheat with my old one, and still does now when on charge, so I use a fan every time I charge my phone with my old and new battery.

Even when I power my phone off overnight with 100% charge, it will drain down to 50%, or if I leave it locked overnight it will be fully gone by the morning.

I have also tried factory resetting the phone and sing different chargers and they have had no effect.

Does anyone have any other suggestions?

Thank you.

*****Edit*****

Another fault is often when I power off my Phone, and then on again, the date and time will reset. I don’t know if this fault is related to the charging or not.

Thank you!