Power Bank with old Tablet Batteries

Diy clip : https://youtu.be/1N0Tsdp4dA4

Hello,
When my school change old tablet batteries, i take it for recycle in PowerBank... one with 2 cells batteries, and a second with 4 cells batteries.

For make it, you will need a
- "DIY power bank module", 1,5euros on aliexpress/ebay (watch my video on youtube),
- lithium tablet battery size : Large 56/57mm ; Longer 120/122mm ; Height 3/4mm
Paramètres d'impression 3D

Don't need support.
For quick print, i use 1mm hole buse. I have try wit