BQ27427: Can`t achieve a successful learning cycle

Hello Kfir,

The most likely cause is due to not having the right chemID and could you send your GPCCHEM calculator report that shows your error % difference. If your ChemID is indeed below 3% error difference than reference these 

GPCCHEM:
https://www.ti.com/tool/GPCCHEM

[FAQ] Why is the Update Status not updating from 4 to 5?:
https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1263138/faq-why-is-the-update-status-not-updating-from-4-to-5

[FAQ] Why is the Update Status register not updating from 5 to 6?:
https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1263623/faq-why-is-the-update-status-register-not-updating-from-5-to-6

Thank you,
Alan 

I did not test for a specific ChemID.

I assumed that for a Li-Po battery with a 4.2V nominal voltage, I should select ChemID 1202 and perform a learning cycle.

What is the correct procedure for selecting a fuel gauge?

Should I first determine the ChemID using any fuel gauge and then select a compatible gauge IC based on the identified chem ID?

Hello Kfir, 

The way you would test  for a chemID is through the GPPCCHEM calculator, the tool would tell you the error difference from your cell to the chemID, typically anything than 3% or lower works. Another thing to note is that all our current generation fuel gauges would work with our chemID library.

Thank you,
Alan