BQ40Z80: Learning failed, VOK never clear

Hello Yangho,

The errors you are seeing can be dude not selecting the right ChemID and/or not performing a calibration in the calibration tab before performing a learning cycle. The first step you should perform is use the GPPCHEM tool to get your ChemID that is 3% less than difference error. Then once this is completed verified that your critical parameters for your data memory registers have been updated to where you would follow this up with a calibration of your parameter. Following this you can perform a learning cycle to get your golden image. 

Can you confirm with a screenshot of what deviation error you received from GPCCHEM tool?

Critical Parameter:
Design Capacity, Design Voltage, Charge Term Taper Current, Discharge (Dsg) Current Threshold, Charge (Chg) Current Threshold, Quit Current and Term Voltage

GPCCHEM calculator: 
https://www.ti.com/lit/an/slva725a/slva725a.pdf?ts=1741788252721&ref_url=https%253A%252F%252Fwww.ti.com%252Ftool%252FGPCCHEM
https://www.ti.com/tool/GPCCHEM

Achieving the successful learning cycle:
https://www.ti.com/lit/an/slua903/slua903.pdf?ts=1741788480031&ref_url=https%253A%252F%252Fwww.ti.com%252Fsitesearch%252Fen-us%252Fdocs%252Funiversalsearch.tsp%253FlangPref%253Den-US%2526nr%253D77%2526searchTerm%253Dhow+to+perform+a+learning+cycle+bqstudio

Thank you,
Alan