XTAR VC4SL cooler stand (battery powered)

When I first bought this charger, I noticed it getting very hot during 4-cell capacity testing. So I designed this cooling stand that cools both the cells and the charger while keeping everything at a comfortable 45° angle.

Assembly is fairly simple. Push the fan into the housing, secure it with screws from the other side, wire everything up, and glue the side covers in place. The charger then slides in from the top. I accidentally used a bit too much glue, but it's only a minor cosmetic defect. Protect all electronics with heat shrink wrap, capton or electrical tape to prevent short circuit!

I used:

1. 1× 18650 cell (I used ~2400mAh and should get around 40-50 hours in one charge, but any capacity will work).

2. IP2312 CC/CV 5V to 4.2V charging board (to charge the cell with a USB-C phone charger). I used 1 mm double-sided tape to mount it so it can still be removed if needed.

3. 1S BMS (to protect the cell; spot welding is required).

4. 20 AWG silicone copper wire (very nice to work with).

5. 5V 19mm latching switch (must be rated for at least 2 A).

6. 12V 120 mm Arctic P12 fan (any 120 mm PC case fan should fit).

7. A tiny 2–28V boost converter (to run the fan at 5V for quiet yet effective cooling).

8. Wago 221 connectors.

Technically, it's possible to run everything without a boost converter, but you won't be able to adjust the fan speed.

Printing:

• ASA

• 6 walls

• 30% infill

• 5 top/bottom layers

Supports for the thin side sections are required. I would use more supports next time (see picture).