Has anyone used an 18650 LiPo cell to power a Mesh unit (eg. Boron, Argon or Xenon


#1

I am investigating battery power options for the Mesh units. The existing LiPo’s are certainly simple to use - plug and go, but 18650 cells are inexpensive and very compact.

Has anyone has experience connecting one?


#2

18650’s have a variety of options for the Lithium Chemistry used and the cell construction.
This can be useful if you need to operate at the extreme temperature ranges for a Li-Po cell.

However, Li-Po’s can be manufactured in “almost” any rectangular size to match the requirements of your project/enclosure.

In my experience, a Quality 18650 Cell with leads, JST connector, and protection circuit will cost more than a similarly rated Li-Po w/ the same.


#3

I’m using a 18650 to power a Photon project and it’s working great.

The cells have a protection PCB attached and I’m using my own charging circuit and a BMS for keeping track of SOC and time until empty numbers.

The 18650 cells are safer than the LiPo pouch cells in my experience because they have a more protective metal housing vs the soft pouch bags the pouch cells are made in.

I’ve seen my fair share of puffed up pouch cell type batteries over the years.

Www.batteryspace.com has tons of different options.


#4

I’m relatively happy powering a boron using an 18650 cell, but everything isn’t yet worked out. First the plus points:

  • The boron has a built-in charger whose charge-termination voltage can be programmed, so I can set it to 4.1V to avoid premature cell aging/failure (at the expense of ~15%-20% capacity).
  • I can buy high quality authentic 18650’s at good prices, I have more difficulty doing that with Li-Po pouch cells.
  • The boron’s PMIC supports a low-voltage cut-out, so it can protect the Li-Ion cell from deep discharge, i.e., external protection circuit not strictly required (not saying it’s not a good idea to have one anyway).

Now the issues:

  • Neither the Argon nor the Xenon have the PMIC, so you need external discharge protection.
  • The Boron has the PMIC plus a fuel cell chip, but they don’t “agree”, so when the PMIC stops charging the fuel cell chip shows around 80% SoC and the cloud console shows a yet different value. Also, when the PMIC stops charging the voltage shown by the fuel cell chip doesn’t match the charge termination voltage. I haven’t dug in to see where the issue lies, I’m sure it’s fixable.

In any case, I recommend reading up on Li-Ion/Li-Po charging and discharging do’s and dont’s!