To Activate FastCharging on Android (LineageOS 17.1) you (PS. Don’t do anything if you’re not having backups and know the risks of modifying your phone.  If Anything breaks, don’t blame us)

Use a terminal, get root (su) copy /init.power.rc to /mnt/sdcard/

cp /init.power.rc to /mnt/sdcard/

edit it.

On the last line look for “write /sys/class/sec/switch/afc_disable 1”

change it to:
“write /sys/class/sec/switch/afc_disable 0”

make a copy of the original rc file
mv init.power.rc init.power.rc.bk
copy the changed file to the / folder
cp /mnt/sdcard/init.power.rc to /
change the group back
chgrp 2000 init.power.rc
change the permissions back
chmod 750 init.power.rc

reboot android. finished