SLUUCA6 October   2021 BQ27Z746

 

  1. 1 Read This First
    1. 1.1 About This Manual
    2. 1.1 Notational Conventions
    3. 1.1 Battery Notational Conventions
    4. 1.1 Trademarks
    5. 1.1 Glossary
  2. 1 Introduction
  3. 2 IO Options
    1. 2.1 Configuration of the GPO Pin
  4. 3 Basic Measurement System
    1. 3.1 Introduction
    2. 3.2 Current and Coulomb Counting
    3. 3.3 Voltage
      1. 3.3.1 Cell Voltage
      2. 3.3.2 Pack Voltage
    4. 3.4 Temperature
      1. 3.4.1 Internal Temperature
      2. 3.4.2 Cell Temperature
      3. 3.4.3 Optional Second Temperature Sensor
      4. 3.4.4 Temperature Configuration
  5. 4 Protections
    1. 4.1 Introduction
    2. 4.2 Hardware-Based Protection
      1. 4.2.1 Cell Undervoltage Protection
      2. 4.2.2 Cell Overvoltage Protection
      3. 4.2.3 Overcurrent in Discharge Protection
      4. 4.2.4 Overcurrent in Charge Protection
      5. 4.2.5 Short Circuit in Discharge Protection
      6. 4.2.6 Threshold Targets
    3. 4.3 Firmware Based Protections
      1. 4.3.1  Cell Undervoltage Protection
      2. 4.3.2  Cell Overvoltage Protection
      3. 4.3.3  Overcurrent in Charge Protection
      4. 4.3.4  Overcurrent in Discharge Protection
      5. 4.3.5  Temperature Protections
      6. 4.3.6  Overtemperature in Charge Protection
      7. 4.3.7  Overtemperature in Discharge Protection
      8. 4.3.8  Undertemperature in Charge Protection
      9. 4.3.9  Undertemperature in Discharge Protection
      10. 4.3.10 Precharge Timeout Protection
      11. 4.3.11 Fast Charge Timeout Protection
      12. 4.3.12 Protections Configuration
      13. 4.3.13 FET Options
      14. 4.3.14 Protections Data Flash Values
        1. 4.3.14.1  CUV—Cell Undervoltage
        2. 4.3.14.2  HCUV—Hardware Cell Undervoltage
        3. 4.3.14.3  COV—Cell Overvoltage
        4. 4.3.14.4  HCOV—Hardware Cell Overvoltage
        5. 4.3.14.5  OCC—Overcurrent In Charge
        6. 4.3.14.6  HOCC—Hardware Overcurrent in Charge
        7. 4.3.14.7  OCD—Overcurrent in Discharge
        8. 4.3.14.8  HOCD—Hardware Overcurrent in Discharge
        9. 4.3.14.9  HSCD—Hardware Short Circuit in Discharge
        10. 4.3.14.10 OTC—Overtemperature in Charge
        11. 4.3.14.11 OTD—Overtemperature in Discharge
        12. 4.3.14.12 UTC—Undertemperature in Charge
        13. 4.3.14.13 UTD—Undertemperature in Discharge
  6. 5 Battery Sensing Output
    1. 5.1 Introduction
    2. 5.2 Automatic Mode
      1. 5.2.1 RLO Mode
      2. 5.2.2 RLO Charge Mode
      3. 5.2.3 BUFFER Mode
    3. 5.3 Hardware-Based Protections
  7. 6 Power Modes
    1. 6.1 Introduction
    2. 6.2 NORMAL Mode
    3. 6.3 SLEEP Mode
      1. 6.3.1 Device Sleep
    4. 6.4 SHIP Mode
    5. 6.5 SHELF Mode
    6. 6.6 SHUTDOWN Mode
      1. 6.6.1 Voltage-Based Shutdown
      2. 6.6.2 AltManufacturerAccess() MAC Shutdown
      3. 6.6.3 Time-Based Shutdown
    7. 6.7 Power Modes Configuration
  8. 7 Gauging
    1. 7.1  Impedance Track (IT) Model
    2. 7.2  Thermal Model
    3. 7.3  Gauging Capacities
    4. 7.4  Learning Cycles
    5. 7.5  Impedance Track Configuration
    6. 7.6  Gas Gauge Modes
    7. 7.7  QMax and Ra
      1. 7.7.1 QMax Initial Values
      2. 7.7.2 QMax Update Conditions
        1. 7.7.2.1 Base Required Conditions
        2. 7.7.2.2 Tracking QMax Updates
        3. 7.7.2.3 Relaxed Cell OCV
        4. 7.7.2.4 OCV Prediction
        5. 7.7.2.5 Cycle Count Based QMax Degradation
        6. 7.7.2.6 92
        7. 7.7.2.7 Fast QMax Update Conditions
        8. 7.7.2.8 QMax and Fast QMax Update Boundary Check
      3. 7.7.3 Ra Table Initial Values
        1. 7.7.3.1 R_a0 Table
        2. 7.7.3.2 R_a0x Table
      4. 7.7.4 Ra Table Update Conditions
      5. 7.7.5 Fast Resistance Scaling
        1. 7.7.5.1 Calculation of Resistance Scale
        2. 7.7.5.2 Negative Resistance Scale
        3. 7.7.5.3 Reset of Resistance Scale
        4. 7.7.5.4 Application of Resistance Scale
        5. 7.7.5.5 Fast Resistance Scaling Configuration
    8. 7.8  FullChargeCapacity (FCC), RemainingCapacity (RemCap), and RelativeStateOfCharge (RSOC)
      1. 7.8.1 Smoothing Engine
        1. 7.8.1.1 Smoothing to 0% in DISCHARGE Mode
        2. 7.8.1.2 Smoothing to 100% in CHARGE Mode
        3. 7.8.1.3 Smoothing in RELAX Mode
    9. 7.9  Impedance Track (IT) Configuration Options
    10. 7.10 State-Of-Health (SOH)
    11. 7.11 Battery Trip Point (BTP)
  9. 8 Lifetime Data Collection
    1. 8.1 Description
    2. 8.2 Reset
  10. 9 Host Interrupts
    1. 9.1 Description
    2. 9.2 Voltage and Temperature Interrupts
    3. 9.3 RSOC Interrupts
    4. 9.4 Host Interrupts Configuration
  11. 10Device Security
    1. 10.1 Description
    2. 10.2 SHA-256 Authentication
      1. 10.2.1 Secure Key
      2. 10.2.2 Authentication Flow
    3. 10.3 Security Modes
      1. 10.3.1 SEALING and UNSEALING Data Flash
      2. 10.3.2 SEALED to UNSEALED
      3. 10.3.3 UNSEALED to FULL ACCESS
  12. 11Advanced Charge Algorithm
    1. 11.1  Introduction
    2. 11.2  Charge Temperature Ranges
    3. 11.3  Voltage Range
      1. 11.3.1 RelativeStateofCharge() Range
    4. 11.4  Charging Current
    5. 11.5  Charging Voltage
      1. 11.5.1 Charge Voltage Compensation for System Impedance
    6. 11.6  Charging Degradation Modes
    7. 11.7  Cell Swelling Control (via Charging Voltage Degradation)
    8. 11.8  Valid Charge Termination
    9. 11.9  Charge and Discharge Alarms
    10. 11.10 Terminate Charge and Discharge Alarms
    11. 11.11 Precharge
    12. 11.12 Charge Disable and Discharge Disable
    13. 11.13 Charge Inhibit
    14. 11.14 Charge Suspend
    15. 11.15 Zero Volt Charging (ZVCHG)
  13. 12Communications
    1. 12.1 HDQ Single-Pin Serial Interface
    2. 12.2 I2C Interface
      1. 12.2.1 I2C Clock Frequency
      2. 12.2.2 I2C Time Out
      3. 12.2.3 I2C Command Waiting Time
      4. 12.2.4 I2C Clock Stretching
  14. 13Manufacture Production
    1. 13.1 Manufacture Testing
      1. 13.1.1 Manufacturing Status Configuration
    2. 13.2 I2C Configuration
    3. 13.3 Manufacturer Information Blocks
    4. 13.4 Verification of Data Flash
    5. 13.5 Calibration
  15. 14Calibration
    1. 14.1 Voltage Calibration
      1. 14.1.1 Cell (BAT) Voltage Calibration
      2. 14.1.2 Pack (PACK) Voltage Calibration
      3. 14.1.3 Voltage Calibration Data Flash
    2. 14.2 Current Calibration
      1. 14.2.1 CC Gain/Capacity Gain Calibration
      2. 14.2.2 Deadbands
        1. 14.2.2.1 Current Deadband
        2. 14.2.2.2 Coulomb Counter Deadband
      3. 14.2.3 Current Calibration Data Flash
    3. 14.3 Temperature Calibration
      1. 14.3.1 Internal Temperature Sensor Calibration
      2. 14.3.2 TS Calibration
      3. 14.3.3 Temperature Calibration Data Flash
      4. 14.3.4 Cell Temp Model
      5. 14.3.5 Internal Temp Model
      6. 14.3.6 2nd Temperature Model
  16. 15Data Commands
    1. 15.1 Standard Data Commands
      1. 15.1.1  0x00/01 ManufacturerAccess()/ControlStatus()
      2. 15.1.2  0x02/03 AtRate()
      3. 15.1.3  0x04/05 AtRateTimeToEmpty()
      4. 15.1.4  0x06/07 Temperature()
      5. 15.1.5  0x08/09 Voltage()
      6. 15.1.6  0x0A/0B BatteryStatus()
      7. 15.1.7  0x0C/0D Current()
      8. 15.1.8  0x10/11 RemainingCapacity()
      9. 15.1.9  0x12/13 FullChargeCapacity()
      10. 15.1.10 0x14/15 AverageCurrent()
      11. 15.1.11 0x16/17 AverageTimeToEmpty()
      12. 15.1.12 0x18/19 AverageTimeToFull()
      13. 15.1.13 0x1E/1F MaxLoadCurrent()
      14. 15.1.14 0x20/21 MaxLoadTimeToEmpty()
      15. 15.1.15 0x22/23 AveragePower()
      16. 15.1.16 0x28/29 InternalTemperature()
      17. 15.1.17 0x2A/2B CycleCount()
      18. 15.1.18 0x2C/2D RelativeStateOfCharge()—RSOC
      19. 15.1.19 0x2E/2F StateOfHealth()
      20. 15.1.20 0x30/31 ChargingVoltage()
      21. 15.1.21 0x32/33 ChargingCurrent()
      22. 15.1.22 0x34/35 TerminateVoltage()
      23. 15.1.23 0x36/0x37/0x38/0x39 Timestamp()
      24. 15.1.24 QMax Cycles() 0x3A/3B
      25. 15.1.25 0x3C/3D DesignCapacity()
      26. 15.1.26 0x3E/3F AltManufacturerAccess()
      27. 15.1.27 0x40/0x5F MACData()
      28. 15.1.28 0x60 MACDataChecksum()
      29. 15.1.29 0x61 MACDataLength()
      30. 15.1.30 0x62/63 VoltHiSetThreshold
      31. 15.1.31 0x64/65 VoltHiClearThreshold
      32. 15.1.32 0x66/67 VoltLoSetThreshold
      33. 15.1.33 0x68/69 VoltLoClearThreshold
      34. 15.1.34 0x6A TempHiSetThreshold
      35. 15.1.35 0x6B TempHiClearThreshold
      36. 15.1.36 0X6C TempLoSetThreshold
      37. 15.1.37 0x6D TempLoClearThreshold
      38. 15.1.38 0x6E InterruptStatus()
      39. 15.1.39 0x6F SOCSetDeltaThreshold
    2. 15.2 0x00, 0x01 ManufacturerAccess() and 0x3E, 0x3F AltManufacturerAccess()
      1. 15.2.1  AltManufacturerAccess() 0x0001 Device Type
      2. 15.2.2  AltManufacturerAccess() 0x0002 Firmware Version
      3. 15.2.3  AltManufacturerAccess() 0x0003 Hardware Version
      4. 15.2.4  AltManufacturerAccess() 0x0004 Instruction Flash Signature
      5. 15.2.5  AltManufacturerAccess() 0x0005 Static DF Signature
      6. 15.2.6  AltManufacturerAccess() 0x0006 Chemical ID
      7. 15.2.7  AltManufacturerAccess() 0x0007 Pre_MACWrite
      8. 15.2.8  AltManufacturerAccess() 0x0008 Static Chem DF Signature
      9. 15.2.9  AltManufacturerAccess() 0x0009 All DF Signature
      10. 15.2.10 AltManufacturerAccess() 0x000B SHELF Enable
      11. 15.2.11 AltManufacturerAccess() 0x000C SHELF Disable
      12. 15.2.12 AltManufacturerAccess() 0x0010 SHUTDOWN Mode
      13. 15.2.13 AltManufacturerAccess() 0x0012 Device Reset
      14. 15.2.14 AltManufacturerAccess() 0x0015 SHIP Mode Enable
      15. 15.2.15 AltManufacturerAccess() 0x0016 SHIP Mode Disable
      16. 15.2.16 AltManufacturerAccess() 0x0017 QMax Day
      17. 15.2.17 AltManufacturerAccess() 0x001F CHG FET Toggle
      18. 15.2.18 AltManufacturerAccess() 0x0020 DSG FET Toggle
      19. 15.2.19 AltManufacturerAccess() 0x0021 Gauging
      20. 15.2.20 AltManufacturerAccess() 0x0022 FET Control
      21. 15.2.21 AltManufacturerAccess() 0x0023 Lifetime Data Collection
      22. 15.2.22 AltManufacturerAccess() 0x0028 Lifetime Data Reset
      23. 15.2.23 AltManufacturerAccess() 0x002D CALIBRATION Mode
      24. 15.2.24 AltManufacturerAccess() 0x002E Lifetime Data Flush
      25. 15.2.25 AltManufacturerAccess() 0x002F Lifetime Data SPEED UP Mode
      26. 15.2.26 AltManufacturerAccess() 0x0030 Seal Device
      27. 15.2.27 AltManufacturerAccess() 0x0035 Security Keys
      28. 15.2.28 AltManufacturerAccess() 0x0041 Device Reset
      29. 15.2.29 AltManufacturerAccess() 0x0047 Tambient Sync
      30. 15.2.30 AltManufacturerAccess() 0x004A Device Name
      31. 15.2.31 AltManufacturerAccess() 0x004B Device Chem
      32. 15.2.32 AltManufacturerAccess() 0x004C Manufacturer Name
      33. 15.2.33 AltManufacturerAccess() 0x004D Manufacture Date
      34. 15.2.34 AltManufacturerAccess() 0x004E Serial Number
      35. 15.2.35 AltManufacturerAccess() 0x0054 OperationStatus
        1. 15.2.35.1 Operation Status A
        2. 15.2.35.2 Operation Status B
      36. 15.2.36 AltManufacturerAccess() 0x0055 ChargingStatus
        1. 15.2.36.1 Temp Range
        2. 15.2.36.2 Charging Status
      37. 15.2.37 AltManufacturerAccess() 0x0056 GaugingStatus
      38. 15.2.38 AltManufacturerAccess() 0x0057 ManufacturingStatus
      39. 15.2.39 AltManufacturerAccess() 0x0060 Lifetime Data Block 1
      40. 15.2.40 AltManufacturerAccess() 0x0061 Lifetime Data Block 2
      41. 15.2.41 AltManufacturerAccess() 0x0062 Lifetime Data Block 3
      42. 15.2.42 ManufacturerAccess() 0x0063 Lifetime Data Block 4
      43. 15.2.43 ManufacturerAccess() 0x0064 Lifetime Data Block 5
      44. 15.2.44 AltManufacturerAccess() 0x0065–0x006B Lifetime SOC Range Table Data Blocks
      45. 15.2.45 AltManufacturerAccess() 0x006C Lifetime Data Block 13
      46. 15.2.46 AltManufacturerAccess() 0x0070 ManufacturerInfo
      47. 15.2.47 AltManufacturerAccess() 0x0071 DAStatus1
      48. 15.2.48 AltManufacturerAccess() 0x0072 DAStatus2
      49. 15.2.49 AltManufacturerAccess() 0x0073 ITStatus1
      50. 15.2.50 AltManufacturerAccess() 0x0074 ITStatus2
      51. 15.2.51 AltManufacturerAccess() 0x0075 ITStatus3
      52. 15.2.52 AltManufacturerAccess() 0x0077 FCC_SOH
      53. 15.2.53 AltManufacturerAccess() 0x0078 Filtered Capacity
      54. 15.2.54 AltManufacturerAccess() 0x007A ManufacturerInfoB
      55. 15.2.55 AltManufacturerAccess() 0x007B ManufacturerInfoC
      56. 15.2.56 AltManufacturerAccess() 0x0097 FET Control Override
      57. 15.2.57 AltManufacturerAccess() 0x00A3 System Reset Enable
      58. 15.2.58 AltManufacturerAccess() 0x00A4 System Reset
      59. 15.2.59 AltManufacturerAccess() 0x00B0 ChargingVoltageOverride
      60. 15.2.60 AltManufacturerAccess() 0x00B1 BattSenseOutput
      61. 15.2.61 AltManufacturerAccess() 0x00E0 Ra Table Cell0
      62. 15.2.62 AltManufacturerAccess() 0x0F00 ROM Mode
      63. 15.2.63 Data Flash Access() 0x4000–0x5FFF
      64. 15.2.64 AltManufacturerAccess() 0x7C40 Switch to HDQ
      65. 15.2.65 AltManufacturerAccess() 0xF080 Exit Calibration Output Mode
      66. 15.2.66 AltManufacturerAccess() 0xF081 Output CC and ADC for Calibration
      67. 15.2.67 AltManufacturerAccess() 0xF083 OutputTemperatureCal
      68. 15.2.68 AltManufacturerAccess() 0xF0A0 ProtectorCalibration
      69. 15.2.69 AltManufacturerAccess() 0xF0A1 ProtectorImage1
      70. 15.2.70 AltManufacturerAccess() 0xF0A2 ProtectorImage2
      71. 15.2.71 AltManufacturerAccess() 0xF0A3 ProtectorImageSave
      72. 15.2.72 AltManufacturerAccess() 0xF0A4 ProtectorImageLock
      73. 15.2.73 AltManufacturerAccess() 0xF0A5 ProtectorFactoryConfig
  17. 16Data Flash Access and Format
    1. 16.1 Data Flash Access
      1. 16.1.1 Minimum Voltage
    2. 16.2 Data Formats
      1. 16.2.1 Unsigned Integer
      2. 16.2.2 Integer
      3. 16.2.3 Floating Point
      4. 16.2.4 Hex
      5. 16.2.5 String
  18. 17Data Flash Summary
    1. 17.1 Data Flash Summary
  19. 18Revision History

7.7.5.2 Negative Resistance Scale

If a negative scale is calculated, it usually indicates significant error in QMax or an incorrect DOD0, which could be from system loading during initialization. When this occurs, Cell 1 RaScale resets to 1000 and GaugingStatus()[NSFM] sets to 1. The gauge attempts to correct the error in DOD by adjusting DOD0 such that DOD0 + (DOD0 Passed Q / QMax) equals the DOD computed from voltage, current, and temperature used for resistance.