I'm trying to do a learn cycle with BQ27500 evm. After the Charge reaches 100% (FC bit gets Set), during the 2 hr relaxation phase the Voltage drops down to 4.17V and the FC bit clears and the SOC shows < 98%! This causes the Learn Cycle to Fail. I don't have any load on the battery. I calibrated the current correctly. I do know that the battery will self discharge after Charger is disabled and it won't stay at 4.2V. I set the design capacity at 350mAHr and Taper current to 20mA. I wait until the FC bit gets Set. I also noticed that the FC bit gets set sometimes at 35mA (instead of 20mA). I also identified correct chemistry using Chemistry cycling and Mathcad.
Need help from gas gauge experts since i've given up and currently scratching my head. I have used BQ27505 (newer version of gas gauge) and never had this issue.