Summary

These are the parts i used to modify my s20 ultra to use a 3x bigger battery.
Battery's from old phones are recycled (4pcs) or you can use new ones.

This is very useful when you don't mind when the phone becomes about 10mm thicker.
The big advantage is the VERY long battery life you get in return.
The battery last about 3 times as long and can be charged with the stock charging port.
The phone in the video has a total battery capacity of 15.600 mah.

very useful when using the phone for gaming or other High battery demanding applications.

The full build video can be found here:
https://youtu.be/M3kSD5O5Cs8