SLUUC54C February   2020  – March 2024 BQ27Z558 , BQ27Z561 , BQ27Z561-R2

 

  1.   1
  2. 1 Preface
    1. 1.1 Read this First
    2. 1.2 Notational Conventions
    3. 1.3 Trademarks
  3.   Introduction
  4. 2 Basic Measurement System
    1. 2.1 Introduction
    2. 2.2 Current and Coulomb Counting
    3. 2.3 Voltage
    4. 2.4 Temperature
      1. 2.4.1 Internal Temperature
      2. 2.4.2 Cell Temperature
      3. 2.4.3 Temperature Configuration
  5. 3 Power Modes
    1. 3.1 Introduction
    2. 3.2 NORMAL Mode
    3. 3.3 SLEEP Mode
      1. 3.3.1 Device Sleep
    4. 3.4 DEEP SLEEP Mode
    5. 3.5 HIBERNATE Mode
    6. 3.6 Power Modes Configuration
  6. 4 Gauging
    1. 4.1  Impedance Track (IT) Model
    2. 4.2  Thermal Model
    3. 4.3  Gauging Capacities
    4. 4.4  Learning Cycles
    5. 4.5  Impedance Track Configuration
    6. 4.6  Gas Gauge Modes
    7. 4.7  QMax and Ra
      1. 4.7.1 QMax Initial Values
      2. 4.7.2 QMax Update Conditions
        1. 4.7.2.1 Base Required Conditions
        2. 4.7.2.2 Tracking QMax Updates
        3. 4.7.2.3 Relaxed Cell OCV
        4. 4.7.2.4 OCV Prediction
        5. 4.7.2.5 Cycle Count Based QMax Degradation
        6. 4.7.2.6 38
        7. 4.7.2.7 Fast QMax Update Conditions
        8. 4.7.2.8 QMax and Fast QMax Update Boundary Check
      3. 4.7.3 Ra Table Initial Values
        1. 4.7.3.1 R_a0 Table
        2. 4.7.3.2 R_a0x Table
      4. 4.7.4 Ra Table Update Conditions
      5. 4.7.5 Fast Resistance Scaling
        1. 4.7.5.1 Calculation of Resistance Scale
        2. 4.7.5.2 Negative Resistance Scale
        3. 4.7.5.3 Reset of Resistance Scale
        4. 4.7.5.4 Application of Resistance Scale
        5. 4.7.5.5 Fast Resistance Scaling Configuration
    8. 4.8  FullChargeCapacity (FCC), RemainingCapacity (RemCap), and RelativeStateOfCharge (RSOC)
      1. 4.8.1 Smoothing Engine
        1. 4.8.1.1 Smoothing to 0% in DISCHARGE Mode
        2. 4.8.1.2 Smoothing to 100% in CHARGE Mode
        3. 4.8.1.3 Smoothing in RELAX Mode
    9. 4.9  Impedance Track (IT) Configuration Options
    10. 4.10 State-Of-Health (SOH)
    11. 4.11 TURBO Mode 3.0
    12. 4.12 Battery Trip Point (BTP)
  7. 5 Lifetime Data Collection
    1. 5.1 Description
    2. 5.2 Reset
  8. 6 Host Interrupts
    1. 6.1 Description
    2. 6.2 Voltage and Temperature Interrupts
    3. 6.3 RSOC Interrupts
    4. 6.4 Host Interrupts Configuration
  9. 7 Programmable Pulse Width
    1. 7.1 Description
    2. 7.2 Programmable Pulse Width Configuration
  10. 8 Device Security
    1. 8.1 Description
    2. 8.2 SHA-256 Authentication
      1. 8.2.1 Secure Key
      2. 8.2.2 Authentication Flow
    3. 8.3 Security Modes
      1. 8.3.1 SEALING and UNSEALING Data Flash
      2. 8.3.2 SEALED to UNSEALED
      3. 8.3.3 UNSEALED to FULL ACCESS
  11. 9 Advanced Charge Algorithm
    1. 9.1  Introduction
    2. 9.2  Charge Temperature Ranges
    3. 9.3  Voltage Range
      1. 9.3.1 RelativeStateofCharge() Range
    4. 9.4  Charging Current
    5. 9.5  Charging Voltage
      1. 9.5.1 Charge Voltage Compensation for System Impedance
    6. 9.6  Charging Degradation Modes
    7. 9.7  Cell Swelling Control (via Charging Voltage Degradation)
    8. 9.8  Valid Charge Termination
    9. 9.9  Charge and Discharge Alarms
    10. 9.10 Terminate Charge and Discharge Alarms
    11. 9.11 Precharge
    12. 9.12 Maintenance Charge
    13. 9.13 Charge Inhibit
  12. 10Communications
    1. 10.1 HDQ Single-Pin Serial Interface
    2. 10.2 I2C Interface
      1. 10.2.1 I2C Clock Frequency
      2. 10.2.2 I2C Time Out
      3. 10.2.3 I2C Command Waiting Time
      4. 10.2.4 I2C Clock Stretching
  13. 11Manufacture Production
    1. 11.1 Manufacture Testing
      1. 11.1.1 Manufacturing Status Configuration
    2. 11.2 I2C Configuration
    3. 11.3 Manufacturer Information Blocks
    4. 11.4 Verification of Data Flash
    5. 11.5 Calibration
  14.   Calibration
    1. 12.1 Cell (BAT) Voltage Calibration
      1. 12.1.1 Voltage Calibration Data Flash
    2. 12.2 Current Calibration
      1. 12.2.1 CC Gain/Capacity Gain Calibration
      2. 12.2.2 Deadbands
        1. 12.2.2.1 Current Deadband
        2. 12.2.2.2 Coulomb Counter Deadband
      3. 12.2.3 Current Calibration Data Flash
    3. 12.3 Temperature Calibration
      1. 12.3.1 Internal Temperature Sensor Calibration
      2. 12.3.2 TS Calibration
      3. 12.3.3 Temperature Calibration Data Flash
      4. 12.3.4 Cell Temp Model
      5. 12.3.5 Internal Temp Model
  15. 12Data Commands
    1. 12.1 Standard Data Commands
      1. 12.1.1  0x00/01 ManufacturerAccess()/ControlStatus()
      2. 12.1.2  0x02/03 AtRate()
      3. 12.1.3  0x04/05 AtRateTimeToEmpty()
      4. 12.1.4  0x06/07 Temperature()
      5. 12.1.5  0x08/09 Voltage()
      6. 12.1.6  0x0A/0B BatteryStatus()
      7. 12.1.7  0x0C/0D Current()
      8. 12.1.8  0x10/11 RemainingCapacity()
      9. 12.1.9  0x12/13 FullChargeCapacity()
      10. 12.1.10 0x14/15 AverageCurrent()
      11. 12.1.11 0x16/17 AverageTimeToEmpty()
      12. 12.1.12 0x18/19 AverageTimeToFull()
      13. 12.1.13 0x1E/1F MaxLoadCurrent()
      14. 12.1.14 0x20/21 MaxLoadTimeToEmpty()
      15. 12.1.15 0x22/23 AveragePower()
      16. 12.1.16 0x28/29 InternalTemperature()
      17. 12.1.17 0x2A/2B CycleCount()
      18. 12.1.18 0x2C/2D RelativeStateOfCharge()—RSOC
      19. 12.1.19 0x2E/2F StateOfHealth()
      20. 12.1.20 0x30/31 ChargingVoltage()
      21. 12.1.21 0x32/33 ChargingCurrent()
      22. 12.1.22 0x34/35 TerminateVoltage()
      23. 12.1.23 0x36/0x37/0x38/0x39 Timestamp()
      24. 12.1.24 QMax Cycles() 0x3A/3B
      25. 12.1.25 0x3C/3D DesignCapacity()
      26. 12.1.26 0x3E/3F AltManufacturerAccess()
      27. 12.1.27 0x40/0x5F MACData()
      28. 12.1.28 0x60 MACDataChecksum()
      29. 12.1.29 0x61 MACDataLength()
      30. 12.1.30 0x62/63 VoltHiSetThreshold
      31. 12.1.31 0x64/65 VoltHiClearThreshold
      32. 12.1.32 0x66/67 VoltLoSetThreshold
      33. 12.1.33 0x68/69 VoltLoClearThreshold
      34. 12.1.34 0x6A TempHiSetThreshold
      35. 12.1.35 0x6B TempHiClearThreshold
      36. 12.1.36 0X6C TempLoSetThreshold
      37. 12.1.37 0x6D TempLoClearThreshold
      38. 12.1.38 0x6E InterruptStatus()
      39. 12.1.39 0x6F SOCSetDeltaThreshold
    2. 12.2 0x70, 0x71 SusTurboPwr()
    3. 12.3 0x72, 0x73 MaxTurboPwr()
    4. 12.4 0x74, 0x75 SusTurboCurr()
    5. 12.5 0x76, 0x77 MaxTurboCurr()
    6. 12.6 0x78, 0x79 TurboSysR()
    7. 12.7 0x7A, 0x7B TurboEdv()
    8. 12.8 0x00, 0x01 ManufacturerAccess() and 0x3E, 0x3F AltManufacturerAccess()
      1. 12.8.1  AltManufacturerAccess() 0x0001 Device Type
      2. 12.8.2  AltManufacturerAccess() 0x0002 Firmware Version
      3. 12.8.3  AltManufacturerAccess() 0x0003 Hardware Version
      4. 12.8.4  AltManufacturerAccess() 0x0004 Instruction Flash Signature
      5. 12.8.5  AltManufacturerAccess() 0x0005 Static DF Signature
      6. 12.8.6  AltManufacturerAccess() 0x0006 Chemical ID
      7. 12.8.7  AltManufacturerAccess() 0x0007 Pre_MACWrite
      8. 12.8.8  AltManufacturerAccess() 0x0008 Static Chem DF Signature
      9. 12.8.9  AltManufacturerAccess() 0x0009 All DF Signature
      10. 12.8.10 AltManufacturerAccess() 0x0012 Device Reset
      11. 12.8.11 AltManufacturerAccess() 0x0017 QMax Day
      12. 12.8.12 AltManufacturerAccess() 0x0021 Gauging
      13. 12.8.13 AltManufacturerAccess() 0x0023 Lifetime Data Collection
      14. 12.8.14 AltManufacturerAccess() 0x0028 Lifetime Data Reset
      15. 12.8.15 AltManufacturerAccess() 0x002D CALIBRATION Mode
      16. 12.8.16 ManufacturerAccess() 0x002E Lifetime Data Flush
      17. 12.8.17 ManufacturerAccess() 0x002F Lifetime Data SPEED UP Mode
      18. 12.8.18 AltManufacturerAccess() 0x0030 Seal Device
      19. 12.8.19 AltManufacturerAccess() 0x0035 Security Keys
      20. 12.8.20 AltManufacturerAccess() 0x0037 Authentication Key
      21. 12.8.21 AltManufacturerAccess() 0x0041 Device Reset
      22. 12.8.22 AltManufacturerAccess() 0x0044 Set Deep Sleep
      23. 12.8.23 AltManufacturerAccess() 0x0045 Clear Deep Sleep
      24. 12.8.24 AltManufacturerAccess() 0x0046 Pulse GPIO
      25. 12.8.25 AltManufacturerAccess() 0x0047 Tambient Sync
      26. 12.8.26 AltManufacturerAccess() 0x0047 Clear GPIO
      27. 12.8.27 AltManufacturerAccess() 0x0047 Set GPIO
      28. 12.8.28 AltManufacturerAccess() 0x004A Device Name
      29. 12.8.29 AltManufacturerAccess() 0x004B Device Chem
      30. 12.8.30 AltManufacturerAccess() 0x004C Manufacturer Name
      31. 12.8.31 AltManufacturerAccess() 0x004D Manufacture Date
      32. 12.8.32 AltManufacturerAccess() 0x004E Serial Number
      33. 12.8.33 AltManufacturerAccess() 0x0054 OperationStatus
        1. 12.8.33.1 Operation Status A
        2. 12.8.33.2 Operation Status B
      34. 12.8.34 AltManufacturerAccess() 0x0055 ChargingStatus
        1. 12.8.34.1 Temp Range
        2. 12.8.34.2 Charging Status
      35. 12.8.35 AltManufacturerAccess() 0x0056 GaugingStatus
      36. 12.8.36 AltManufacturerAccess() 0x0057 ManufacturingStatus
      37. 12.8.37 AltManufacturerAccess() 0x0060 Lifetime Data Block 1
      38. 12.8.38 AltManufacturerAccess() 0x0062 Lifetime Data Block 3
      39. 12.8.39 ManufacturerAccess() 0x0063 Lifetime Data Block 4
      40. 12.8.40 ManufacturerAccess() 0x0065-0x006B Lifetime SOC Range Table Data Blocks
      41. 12.8.41 AltManufacturerAccess() 0x0070 ManufacturerInfo
      42. 12.8.42 AltManufacturerAccess() 0x0071 DAStatus1
      43. 12.8.43 AltManufacturerAccess() 0x0072 DAStatus2
      44. 12.8.44 AltManufacturerAccess() 0x0073 ITStatus1
      45. 12.8.45 AltManufacturerAccess() 0x0074 ITStatus2
      46. 12.8.46 AltManufacturerAccess() 0x0075 ITStatus3
      47. 12.8.47 AltManufacturerAccess() 0x0077 FCC_SOH
      48. 12.8.48 AltManufacturerAccess() 0x0078 Filtered Capacity
      49. 12.8.49 AltManufacturerAccess() 0x007A ManufacturerInfoB
      50. 12.8.50 AltManufacturerAccess() 0x007B ManufacturerInfoC
      51. 12.8.51 ManufacturerAccess() 0x00B0 ChargingVoltageOverride
      52. 12.8.52 AltManufacturerAccess() 0x0F00 ROM Mode
      53. 12.8.53 Data Flash Access() 0x4000–0x5FFF
      54. 12.8.54 AltManufacturerAccess() 0x7C40 Switch to HDQ
      55. 12.8.55 AltManufacturerAccess() 0xF080 Exit Calibration Output Mode
      56. 12.8.56 AltManufacturerAccess() 0xF081 Output CC and ADC for Calibration
  16. 13Data Flash Access and Format
    1. 13.1 Data Flash Access
      1. 13.1.1 Minimum Voltage
    2. 13.2 Data Formats
      1. 13.2.1 Unsigned Integer
      2. 13.2.2 Integer
      3. 13.2.3 Floating Point
      4. 13.2.4 Hex
      5. 13.2.5 String
  17. 14Data Flash Summary
    1. 14.1 Data Flash Table
  18. 15Revision History

4.7 QMax and Ra

The total battery capacity is found by comparing states-of-charge before and after applying the load with the amount of charge passed. When an applications load is applied, the impedance of the cell is measured by comparing the open circuit voltage (OCV) obtained from a predefined function for the present state-of-charge with the measured voltage under load.

Measurements of OCV and charge integration determine the chemical state-of-charge (SOC) and chemical capacity (QMax). Ra is the impedance of the cell at 25°C at various states-of-charge.

The BQ27Z561-R2 acquires and updates the battery-impedance profile during normal battery usage. It uses this profile, along with the state-of-charge and QMax value, to determine FullChargeCapacity() and RelativeStateOfCharge() specifically for the configured load and present temperature. FullChargeCapacity() reports a capacity or energy available from a fully charged battery reduced by Reserve Cap-mAh or Reserve Cap-cWh under the configured load and present temperature until Voltage() reaches end-of-discharge voltage (EDV).