SLUAAA1 October   2021 BQ21061 , BQ21062 , BQ24179 , BQ25150 , BQ25155 , BQ25157 , BQ25672 , BQ25790 , BQ25792 , BQ25798 , BQ25882 , BQ25883 , BQ25887 , BQ25895 , BQ25896 , BQ25898 , BQ25898D

 

  1.   Trademarks
  2. 1Introduction
  3. 2Battery Characterization
  4. 3Generating the Lookup Table
  5. 4BQ25155 Register Configuration
  6. 5Best Use Cases
  7. 6Python Lookup Table Generator
  8. 7MSP430 Code Snippet

2 Battery Characterization

The following steps must be taken to generate the voltage versus SOC table. This setup requires a voltmeter, ammeter, electronic load, and appropriate data logging equipment. Figure 2-1 shows a diagram of the test setup.

GUID-20210827-SS0I-FTMD-KLQW-738N12ZMFTQB-low.pngFigure 2-1 Test Setup
  1. Ensure the battery is charged to full per its manufacturer’s specification.
  2. Connect the voltmeter to positive battery terminal.
  3. Connect the electronic load to positive battery terminal with ammeter in series.
  4. Ensure logging software is turned on and the voltage and current readings are being taken at regular intervals (every 5 to 10 seconds is okay).
  5. Set load to your applications typical discharge rate and discharge battery to its end-of-discharge voltage.

A C/10 value or less is ideal to minimize the effects of relaxation. Note this process takes a while (> 10 hours). There are more comments on this assumption in the Best Use Cases section.