What is it?

This tiny, USB-C lipo charger measures just 25x25mmx4mm and can easily output up to 1A of current without getting hot.

This is because unlike most ready-made lipo-chargers like the infamous TP4056, this one doesn't use a linear converter (which is far from efficient), but a full buck converter circuit, which is much more efficient, allowing an efficiency up to 94%. Linear regulators like the TP4056 step down the voltage from 5V to the required battery charging voltage by emitting the "excess" voltage as heat.

It has an onboard-LED which shows the charging status (on: charging, off: fully-charged, blinking: fault) and thanks to the thin, 1.0 mm pcb, it's super slim too (~4mm).

Why did you make it?

I used to have a lot of TP4056 chargers and needed to charge lipo regularly. However, the heat generation of the TP4056 due to its linear nature doesn't make it very suitable when heat generation is an issue or due to a lack of space for passive cooling. I burnt my hands quite a few times when charging 10000mAh lipos 🤕. Furthermore, thanks to its slim pcb (1.0 mm), it will easily fit in many cramped spaces without you having to worry about heat (total height less than 4mm).

What makes it special?

• High efficiency (94%). Beats the TP4056 by far without producing much heat. Even at 1A charging, it barely reaches 30-35 degrees. Hence, it's ideal even for 3d-printed PLA parts
• small size: 25x25x4mm
• USB-C, what else?
• Mounting holes! 2.5mm diameter, all connected to ground
• charging indicator LED. Know when your battery is fully charged
• 2x VBAT connector, 2x GND connector. You can solder any connector you like to these pads.
• 1A charging current

Update Oct 2024

Starting from Oct 2024, the board has been revised to have the blue solder-mask and ENIG (gold) plating, a thickness of 1.0mm instead of 0.6mm (which turned out to be a little fragile). Furthermore, this batch comes pre-assembled hence I do not have to solder anything myself, reducing the probability of issues with soldering etc. and improving reliability.

Spoiler: Due to great user feedback, a new version of this board is also on the way, with an integrated Lipo-fuel gauge IC, selectable current output up to 2A and a JST-connector! Keep checking for more updates!