Michael Rangen Li-Ion Single Cell Implementation

It’s been bothering me that all my designs are tethered. I do use USB-C PD battery packs occasionally, but I’d like to be able to build things that are self contained and house their own rechargeable batteries. I decided I wanted to design a simple board for an 18650 Li-Ion, test it, and then drop the design into future projects.

I whipped something up quickly over the weekend and posted a picture of it on Twitter. It got a lot more attention than I expected it would :sweat_smile: However, I did get some valuable insights from others, such as the benefits of batteries that include protection ICs, the danger that metal battery clips can pose, etc.


I’ve since watched a great video from MicroType Engineering and adjusted my design.

Some changes since the original Tweet:

  • Switched to a battery that has in-built protection and UN38.3 certification
  • Switched to a battery holder that has less potential for shorting out the battery
  • Added Buck/Boost converter
  • Added additional protection circuitry

I still need to layout the board but if anyone would like to review my design I’d love some feedback, this is entirely new territory for me.


Figured out the placement for my components and was able to eliminate a couple of capacitors.
I’ll leave the routing for tomorrow, look at it with a fresh set of eyes.


I think I’m ready to order. The vertical header between the ICs is where the thermistor will be soldered in and I’ll use some Kapton to tape it to the battery. I added a simple battery disconnect with another header near the bottom.

1 - Majority of routing and Gnd fill
2 - GND
3 - Secondary routing and 3.3V fill
4 - GND

I felt this stackup would maximize interplane capacitance.

Layer 1

Layer 3