SLUAA45 April   2020 BQ27Z561

 

  1.   End of Discharge SOC Jump Elimination
    1.     Trademarks
    2. 1 Introduction
    3. 2 Improve Battery Modeling
      1. 2.1 Improve Battery Modeling -- Get Matched ChemID
      2. 2.2 Improve Battery Modeling -- Use GPCRB Tool to Optimize Low-Temperature Performance
    4. 3 Optimize Gauge Configurations
      1. 3.1 Optimize Gauge Configuration -- Load Prediction
        1. 3.1.1 Load Mode
        2. 3.1.2 Load Select
        3. 3.1.3 Discharge Current Threshold and Quit Current
      2. 3.2 Optimize Gauge Configuration -- Enable Smoothing to 0% in Discharge Mode
      3. 3.3 Optimize Gauge Configuration -- Enable Fast Resistance Scaling
      4. 3.4 Optimize Gauge Configuration -- EDV in Steep Zone
    5. 4 Achieve Successful Ra Table, Qmax and DOD0 Learning
      1. 4.1 Complete a Learning Cycle to Update Ra Table and Qmax
      2. 4.2 Add a Dedicated Relaxation to Update DOD0
    6. 5 References

4.2 Add a Dedicated Relaxation to Update DOD0

A dedicated relaxation (zero discharge current) will result in a better DOD0 and Present DOD, because the OCV lookup is more precise than the end-of-charge detection DODatEOC. The gauge will try to estimate a DODatEOC based on the charging voltage, the taper current and the impedance tables. This inherently is less accurate than a dedicated OCV measurement in relax, hence, SOC accuracy improves if relax is added. It can be implemented by the adaptor plugged in trick to power the device to maintain no current out of the battery.