SLUAAT6 July   2024 BQ41Z50

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Manufacture Testing
  5. 2Calibration
    1. 2.1 Cell Voltage Calibration
    2. 2.2 BAT Voltage Calibration
    3. 2.3 PACK Voltage Calibration
    4. 2.4 Current Calibration
      1. 2.4.1 CC Offset Calibration
      2. 2.4.2 Board Offset Calibration
      3. 2.4.3 CC Gain Calibration
    5. 2.5 Temperature Calibration
      1. 2.5.1 Internal Temperature Sensor Calibration
      2. 2.5.2 TS1–TS2–TS3–TS4 Calibration
  6. 3References

2.4.1 CC Offset Calibration

Note:

Due to hardware improvements in this device, CC Offset calibration is not necessary. Only run the CC Offset Calibration procedure if current is observed when no current is present.

  1. Apply a known current of 0 mA, and verify no current is flowing through the sense resistor connected between the SRP and SRN pins.
  2. Externally short the SRN and SRP pins together for best results during CC offset calibration.
  3. If ManufacturerStatus()[CAL] = 0, send 0x002D to ManufacturerAccess() to enable the [CAL] flag.
  4. Send 0xF081 to ManufacturerAccess() to enable raw current output on ManufacturerData().
  5. Poll ManufacturerData() until ZZ increments by 2 before reading data.
  6. Obtain the ADC conversion readings of current from ManufacturerData():
    • ADCCC = AAaa of ManufacturerData()

      Is ADCCC < 0x8000? If yes, use ADCCC; otherwise, ADCCC = –(0xFFFF – AAaa + 0x0001).

  7. Average several readings for higher accuracy. Poll ManufacturerData() until ZZ increments to indicate that updated values are available:
    • ADCCC = [ADCCC(reading n) + … + ADCCC(reading 1)]/n
  8. Read Coulomb Counter Offset Samples from data flash.
  9. Calculate offset value:
    • CC offset = ADCCC × (Coulomb Counter Offset Samples)
  10. Write the new CC Offset value to data flash.
  11. Re-check the current reading and if not accurate, repeat steps 1 – 10.
  12. Send 0x002D to ManufacturerAccess() to clear the [CAL] flag if all calibration is complete.