DIY 18650 Power Bank Kit 🔋 | Build a 22.5W Super Fast Charger for Under $20

In this video, I’m building a custom DIY power bank using a 21-cell 18650 battery case kit with 22.5W super fast charging.
Perfect for travel, camping, or emergency use – and it only costs around $16!

⚠️ Important Info:
This is an empty case kit – batteries are NOT included. You’ll need to purchase 21 flat-top 18650 lithium cells separately.

✔️ Battery Insertion Tips:

Make sure all cells are charged to similar levels

Check each battery’s wrap — it must be undamaged and well insulated

Insert the flat negative pole against the spring terminal

All batteries must face the same direction

Work slowly and carefully — safety first!

📏 I also cut and added custom spacers between the cells to prevent movement inside the housing during use or transport.

💡 LED Module Info:
The LED diffuser plate snaps securely into place. To make it more durable, I also fixed the LED strip inside with hot glue – now it’s stable even for rugged outdoor use.

🔩 Screw Assembly:
The kit includes 7 small screws (3 per side + 1 spare). You’ll only need a small Phillips screwdriver for assembly.

🔋 First Power-Up:
When I powered it on, the battery indicator showed 30%, which is totally normal for freshly inserted cells.
I then charged the pack slowly over several hours to around 95% – this allows all cells to balance properly before first use.

✅ Features of the Kit:

22.5W USB & Type-C Fast Charging

DC Output Port (5V/9V/12V)

Built-in LED Flashlight with 4 Modes (Full, Half, SOS, Flash)

Portable and durable for travel, camping & emergencies

No welding required – great for beginners!

📦 Package Includes:

1x Power bank housing for 21x 18650 batteries

7 screws total (3 per side + 1 spare)

LED light module & buttons (pre-installed)

⚠️ Batteries not included!

🔗 Product Link ():
👉 [https://www.ebay.com/sch/i.html?_nkw=21+cell+18650+battery+bank+case+kit+diy&_sacat=0&_from=R40&_trksid=m570.l1313]