A DIY power bank using the 18650 laptop batteries, with 150watt inverter and USB ports.

Charging through AC or Solar

Step 1: 18650 Batteries

Extracted the batteries from the discarded laptop battery packs and filtered in the good 18650 cells

Charged each cell to full

Step 2: Battery Pack

Steps:

3D printed the battery holder

Soldered the cells (45 in this case) to make fifteen 12.6v cells, delivering 33000 mah

added a 25amp Battery management system and balanced charging.

1. USB sockets

2. Regular wall sockets

3. 1.3 inch oled

4. 2 switches

5. Charging socket

6. LED for status indication

7. Arduino nano

8. 150 watt 12v DC to 240v AC inverter

9. Fuse

10. Step down buck

11. current sensor to track charging and load

12. Buzzer

13. fan

Enclosure made out of 3d printed corners and control console and rest of the area from acrylic sheet of 3mm thickness