BQ78350: Bq78350-R2 Learned FCC Update fault

Please also attach the register log file from a full charge to a full discharge. It's not possible to determine the cause with the configuration alone. We also need to see what happens during discharge and if the battery was charged high enough.

The gauge applies several rules for FCC updates. See TRM https://www.ti.com/lit/ug/sluubd3e/sluubd3e.pdf, 9.1.6 Qualified Discharge.

Hello. The log file shows that VDQ = 1 all through the discharge while bit 14 (EDV2) in Gauging Status is never set. This implies that the discharge qualifies for FCC update but the cell voltage never dropped below EDV2. You use EDV compensation so we do not know exactly what EDV2 the gauge calculated. Please provide the input and the output for GPC CEDV.

If possible, please test this again with compensation disabled (set CEDV Gauging Configuration to 0x0002). The gauge will then use your EDV2 setting of 3144mV. Your log file shows that cell voltage drops below this voltage so the gauge should update FCC if EDV2 is fixed. If this is the case then the problem is with your CEDV coefficients that you got from GPC CEDV. 

If you set EDV_CMP, you will have to obtain the correct CEDV parameters from GPC CEDV.

If you don't set EDV_CMP (e.g. you don't have the correct CEDV parameters and don't have a way to generate the required log files), the gauge will not compensate EDV for a change in load or temperature, therefore FCC will update at a fixed EDV2 which may not be the correct voltage for BatLow% because this voltage shifts based on load or temperature. The end effect will be less accurate gauging.