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.

image

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.


2 Likes

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.



4 Likes

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.




Stackup:
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


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