The board will aid in protecting our batteries. The battery pack should be at least 80% charged (i.e. 20% depth of discharge) at any given time. To make this possible, we will use a fuel gauge to monitor the depth of discharge of the battery pack. Our battery pack is 2s2p Lithium Ion batteries. This project comes in two parts. See:
A list of sequential tasks for the project. The project is complete when all tasks are complete
Space for research notes, open questions, progress logs
The following Digi-key search has the most promising chips from what I've seen, with the reasoning being that they are in stock, use I2C, and are rated for our 2 series total pack voltage.
https://www.digikey.ca/en/products/filter/battery-management/713?s=N4IgjCBcoMwGxVAYy[…]rg7R5GzyJoEh5KhVmAAEhugVhrieIAihugAm6kX8EF7qgioAnkq9PujYKA1AA
The two links below seem like the best standalone fuel gauge/BMS IC options, but are a bit overkill based on the requirements you told me before (these ones have the ability to have overcurrent, overvoltage protection and cell balancing, but those features can be disabled). These ones are good because the peripheral circuitry is simple and most importantly, they are rated for the pack voltage.
https://www.digikey.ca/en/products/detail/texas-instruments/BQ28Z620DRZR/19236207
https://www.digikey.ca/en/products/detail/analog-devices-inc-maxim-integrated/MAX17320X20-T/17878638
I found other ICs (which we looked at together a couple weeks back) that have simple peripheral circuitry as well, but only support 1 cell for SOC estimation. Those ICs don't have the advanced features. Also, the Monolithic ICs in the first search I linked above are not ideal IMO because they are "fuel gauge" ICs only, so they take the voltage and current measurements, but require another Monolithic BMS IC to do the SOC estimation and other advanced features (overcurrent, overvoltage, cell balancing). So those seem to have higher cost and complexity for no benefit.
Proceeding with TI BQ28Z620DRZR Fuel Gauge IC for board design.
https://www.digikey.ca/en/products/detail/texas-instruments/BQ28Z620DRZR/19236207