Part Number:BQ20Z80A-V110
We are having trouble with the gas gauging accuracy on the BQ20Z80 V1.10. It appears that on discharge that the absolute capacity and relative capacity both stop decrementing at ~20% SOC even though I can still get that ~20% out of the pack before the BMS opens the discharge FETs. It will then recalibrate and adjust to 0% after resting. We have tried a couple times to follow the SLA334B to help with the accuracy issues and make a golden file. The trouble is that the 3 calibration cycles do not appear to be helping the issue. We can see that after the 2 hour rest once the pack is charged and the 5 hour rest once the pack is discharge that the recalibration occurs; however it continually stops decrementing at ~20% on relative capacity and adjusting later. Something else we noticed is that the relative capacity ~20% is right around 3.48-3.5V/cell. Another data point is the QMAX values appear to be updating with each cycle as they are suppose to when making a golden file.