Only if you cannot get into recovery and stuck in fastboot, then you have to install MIUI whole again.
If you still can get to TWRP fine, then just use the updated firmware from this thread
https://xdaforums.com/redmi-note-7-pro/development/firmware-xiaomi-redmi-note-7-pro-t3925870
---------- Post added at 04:35 AM ---------- Previous post was at 04:30 AM ----------
Can you get to fastboot? make sure you use the correct TWRP that Dyneteve mentioned: Boot to recovery ( peter's one ), which is this one:
https://xdaforums.com/redmi-note-7-pro/development/unofficial-twrp-3-3-1-proper-t3933531
---------- Post added at 04:38 AM ---------- Previous post was at 04:35 AM ----------
Using this ROM from day one, I never had issue with battery, normally 1 charge per 2 days. No battery drain, no heat issue, quick charge perfectly.
If you have issue, make sure you don't have weird software running, clean rom installation, a proper charge, please remember out of the box charge is a 12W no quick charge