Introduction: DIY Laptop Power Bank

Part list:

1. 1200W 20A DC Converter Boost Step Up Power Supply

2. Mini Digital Voltmeter Ammeter DC 100V 10A

3. 4Pcs Banana Plug Socket

4. Banana Plug Jack

5. 5K, 50k Ohm Potentiometer Single Linear

6. 4S 40A BMS

7. Rotary Taper Potentiometer Hole

8. 4 Pin DPST ON-OFF Rocker Boat Switch

9. 2/3/5 Holes Spring Conductor Terminal Block Electric Cable Wire Connector

Step 1: Make 4S4P Battery Pack

1. Note the following important points:

- Cells must have nearly the same voltage and internal resistance.

- Fully charge the cells and let them drain after 1 week. You will now measure their capacity again.

2. If you do not have the required number of cells, do as I do.

- Set up small packages of 1S4P with the same capacity

- We will connect each 1S4P battery pack to form 4S4P battery pack. When the 1S1P battery pack ends we will charge them, one by one.

- Notice the battery buzzer is important in this case

Step 2: Complete the Project

1. Please note that our booster circuit has the maximum power calculated as follows

- Output power = input voltage x 10A

2. We will replace the 200k Ohm potentiometer with a 50k Ohm potentiometer.

- Because it will limit the output of the booster circuit to about 22v. It will be safer for your computer.

3. The box we can make with the shell of the old computer PSU. It is wide enough for you to add a fan if you use it for a different purpose with a large power.

4. With old computer power supply and RUIDENG DPS5020 circuit.

- It will be a great power source for your other projects. It's not just about powering laptops.

Good luck. Thank you for reading