SLUA857A December   2017  – September 2022 BQ27426

 

  1.   bq27426 Gauging Design for Applications With 2-S Li-Ion Battery
  2.   Trademarks
  3. 1Introduction
  4. 2Implementation
  5. 3Voltage Calibration and Accuracy
  6. 4bq27426 Configuration and Learning Process
  7. 5Cell Balancing Consideration
  8. 6Revision History

1 Introduction

Host-side application of a single-cell gas gauge, bq27426, requires direct battery voltage measurement from the battery pack. For a single-cell pack, the bq27426 uses the BAT pin to measure the pack voltage directly with the BAT pin internal translation circuits enabled. The maximum voltage that can be applied to the BAT pin is 5 V.

If a 2-S battery pack is used, the bq27426 cannot directly measure the battery voltage because the pack voltage may be much higher than the maximum operating voltage on the BAT pin. An external resistive voltage divider circuit is required to divide down the battery voltage to the range equivalent of a single-cell battery.