Variable voltage power bank

This power bank can boost the voltage of 18650 batteries to 4-28V.
This model consists of a case and two covers, with and without a logo.
To build this model, you will need the following parts:
1. 18650 Battery x 2 ea
2. 18650 Battery holder x 2 ea
3. J5019 charger module
4. Voltmeter
5. Variable Resister 10K
6. Knob
7. USB connector
8. DC Jack
9. Insert nut M3 x 4 x 5 x 6ea
10. M3 bolt x 6ea

https://youtu.be/BPHMeK6J_so?si=cX-JxHh9KU7XWpOk