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

2.4.3 CC Gain Calibration

  1. Apply a known current (typically 1A to 2A), and verify ICC is flowing through the sense resistor connected between the SRP and SRN pins.
  2. If ManufacturerStatus()[CAL] = 0, send 0x002D to ManufacturerAccess() to enable the [CAL] flag.
  3. Send 0xF081 to ManufacturerAccess() to enable raw CC output on ManufacturerData().
  4. Poll ManufacturerData() until ZZ increments by 2 before reading data.
  5. Read the ADC conversion readings of current from ManufacturerData():
    • ADCCC = AAaa of ManufacturerData()

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

  6. 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
  7. Read Coulomb Counter Offset Samples from data flash.
  8. Calculate gain values:
    Equation 4. CC Gain = IccADCcc-Board Offset + CC OffsetCoulomb Counter Offset Samples×216
  9. Write the new CC Gain and value to data flash.
  10. Re-check the current reading. If the reading is not accurate, repeat steps 1 – 9.
  11. Send 0x002D to ManufacturerAccess() to clear the [CAL] flag if all calibration is complete.
Note:

Capacity Gain is no longer used in the BQ41xxx product family and must not be used or modified.