SLUAB20A May   2025  – July 2025 BQ41Z50 , BQ41Z90

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Battery Gauging Algorithm Background
  6. 3Battery Modeling
  7. 4Battery State of Charge Estimation and Remaining Capacity Prediction
  8. 5Challenges Modeling Battery Response to Dynamic Load Currents
  9. 6Approaches to Deal with Battery Dynamics
    1. 6.1 Benefits to Gauging Accuracy for Dynamic Loads
    2. 6.2 Algorithm Performance
  10. 7Summary
  11. 8References
  12. 9Revision History

1 Introduction

This application note describes Texas Instruments' Dynamic Z-Track™ algorithm used in the BQ41z50 and other Texas Instruments' battery gauge devices. The gauging algorithm is a successor to the Impedance Track™ gauging algorithm used in many previous TI battery gauge devices such as BQ40z50, BQ27z561, BQ27z746, BQ34z100, and so forth. The Dynamic Z-Track algorithm is designed to enable accurate battery gauging in application environments when the battery load current exhibits frequent and rapid changes over long time periods.