SLUUDA0
April 2026
BQ27Z855
1
Read This First
About This Manual
Notational Conventions
Battery Notational Conventions
Trademarks
Glossary
1
IO Options
1.1
Configuration of the INT Pin
2
Basic Measurement System
2.1
Introduction
2.2
Current and Coulomb Counting
2.3
Voltage
2.3.1
Cell Voltage
2.3.2
Pack Voltage
2.4
Temperature
2.4.1
Internal Temperature
2.4.2
Cell Temperature
2.4.3
Temperature Configuration
3
Protections
3.1
Introduction
3.2
Cell Undervoltage Protection
3.3
Cell Undervoltage Compensated Protection
3.4
Cell Overvoltage Protection
3.5
Overcurrent in Charge Protection
3.6
Overcurrent in Discharge Protection
3.7
Hardware-Based Protection
3.7.1
Analog Over Current Charge Protection (AOCC)
3.7.2
Analog Over Current Discharge Protection (AOCD)
3.7.3
Short Circuit in Discharge Protection
3.7.4
ACUV (Cell Under Voltage)
3.7.5
ACOV (Cell Over Voltage)
3.8
Temperature Protections
3.8.1
Overtemperature in Charge Protection
3.8.2
Overtemperature in Discharge Protection
3.8.3
Overtemperature FET Protection
3.8.4
Undertemperature in Charge Protection
3.8.5
Undertemperature in Discharge Protection
3.9
Host Watchdog Protection
3.10
Precharge Timeout Protection
3.11
Fast Charge Timeout Protection
3.12
Overcharge Protection
3.13
OverCharging Voltage Protection
3.14
OverCharging Current Protection
3.15
OverPrecharging Current Protection
4
Integrated Short-Circuit Indication (ISI)
4.1
Introduction
4.2
Configuration
4.2.1
Self-Discharge Current
4.2.2
Low Internal Short Threshold
4.2.3
High Internal Short Threshold
4.2.4
Threshold Passes to Completion
4.2.5
Manufacturing Completion Timeout
4.3
ISI Configuration Parameters
4.3.1
ISI Configuration
5
Permanent Fail
5.1
Introduction
5.1.1
Black Box Recorder
5.2
Safety Cell Undervoltage Permanent Fail
5.2.1
SUV Check Option
5.3
Safety Cell Overvoltage Permanent Fail
5.4
Safety Overcurrent in Charge Permanent Fail
5.5
Safety Overcurrent in Discharge Permanent Fail
5.6
Safety Overtemperature Cell Permanent Fail
5.7
Safety Overtemperature FET Permanent Fail
5.8
Capacity Degradation Permanent Fail
5.9
Charge FET Permanent Fail
5.10
Discharge FET Permanent Fail
5.11
Battery Swelling Detection Permanent Fail
5.12
Data Flash (DF) Permanent Fail
5.13
Cell Overvoltage Latch Permanent Failure
5.14
Manual Permanent Failure
5.15
Permanent Fail ISI
5.16
Internal Short-Circuit Indication Low Permanent Fail
5.17
Internal Short-Circuit Indication High Permanent Fail
6
Power Modes
6.1
NORMAL Mode
6.1.1
System Present Detection Configuration
6.1.1.1
System Present
6.1.1.2
Battery Pack Removed
6.2
SLEEP Mode
6.2.1
Device Sleep
6.2.2
IN SYSTEM SLEEP Mode
6.2.3
ManufacturerAccess() MAC Sleep
6.2.4
Current Wake Function
6.3
SHIP Mode
6.4
SHUTDOWN Mode
6.4.1
VOLTAGE BASED SHUTDOWN
6.4.2
ManufacturerAccess() MAC Shutdown
6.4.3
Time-Based Shutdown
6.4.4
Low RSOC Time-Based Shutdown
6.4.5
Power Save Shutdown
6.4.6
IO Based Shutdown
6.5
Startup ENAB Hold Time
6.6
Option to Manage Unintended Wakeup from Shutdown
6.7
Emergency FET Shutdown (EMSHUT)
6.7.1
Enter Emergency FET Shutdown Through SHUTDN
6.7.2
Enter Emergency FET Shutdown Through MFC
6.7.3
Exit Emergency FET Shutdown
6.8
STORAGE Mode
6.9
System Disconnect
7
Gauging
7.1
Introduction
7.2
Dynamic Z-Track Configuration
7.3
Gas Gauge Modes
7.4
QMax and Ra
7.4.1
QMax Initial Values
7.4.2
QMax Update Conditions
7.4.3
OCV Prediction
7.4.4
Fast Qmax Update Conditions
7.4.5
QMax and Fast Qmax Update Boundary Check
7.4.6
Ra Table Initial Values
7.4.7
Ra Table Update Conditions
7.4.8
Application of Resistance Scaling
7.5
FullChargeCapacity(FCC), RemainingCapacity(RemCap), and RelativeStateOfCharge(RSOC)
7.6
Dynamic Z-Track Configuration Options
7.7
State of Health (SOH)
7.8
RSOC Rounding Option
7.9
RSOC 1% Hold
7.10
Accumulated Charge Measurement
8
Gauging for Silicon Anode Battery
8.1
Introduction
8.2
Capacity Loss And OCV Drift
8.3
Silicon Anode Battery Gauging
8.4
Silicon Anode Gauging Parameters
8.5
Design Qmax
8.6
ManufacturerAccess() 0x0040 SiAnode Status
8.7
ZT SiAnode Gauging Configuration
9
Lifetime Data Collection
9.1
Description
9.2
Reset
10
Linear Charging Functions
10.1
Introduction
10.2
Charger Detect (CHGR_DET) Functionality
10.3
CHG FET FSM and Mode-to-mode Switching (Linear Charger Modes)
10.4
Linear Charge Profile
11
Host Interrupts
11.1
Description
11.2
Host Interrupts Configuration
12
Device Security
12.1
Description
12.2
SHA-256 Authentication
12.2.1
Authentication Flow
12.3
Security Modes
12.3.1
SEALING and UNSEALING Data Flash
12.3.2
SEALED to UNSEALED
12.3.3
UNSEALED to FULL ACCESS
13
Advanced Charge Algorithm
13.1
Introduction
13.2
Charge Temperature Ranges
13.3
Voltage Range
13.3.1
Voltage or RelativeStateofCharge() Range
13.4
Charging Current
13.5
Charging Voltage
13.6
Valid Charge Termination
13.7
Charge and Discharge Termination Flags
13.8
Terminate Charge and Discharge Alarms
13.9
Zero Volt Charging (ZVCHG)
13.10
Precharge
13.11
Maintenance Charge
13.12
Charge Disabled
13.13
Charge Inhibit
13.14
Charge Suspend
13.15
ChargingVoltage() Rate of Change
13.16
ChargingCurrent() Rate of Change
13.17
Charging Loss Compensation
13.18
Cycle Count/SOH Based Degradation of Charging Voltage and Current
13.18.1
Degradation Modes
13.18.1.1
Cycle Count Based Degradation
13.18.1.2
SOH Based Degradation
13.18.1.3
Runtime Based Degradation
13.18.2
Degradation Process
13.18.2.1
Charging Voltage Degradation Process
13.18.2.2
Charging Current Degradation Process
13.19
Elevated Charge Degradation
13.20
Elevated Voltage Extended Charge Degradation
13.21
Charge Voltage Compensation for System Impedance
13.22
Cell Swelling Control (via Charging Voltage Degradation)
14
Communications
14.1
I2C Interface
14.1.1
I2C Clock Frequency
14.1.2
I2C Time Out
14.1.3
I2C Command Waiting Time
14.1.4
I2C Clock Stretching
15
Calibration
15.1
Voltage Calibration
15.1.1
Cell (BAT) Voltage Calibration
15.1.2
Pack (PACK) Voltage Calibration
15.1.3
Voltage Calibration Data Flash
15.2
Current Calibration
15.2.1
CC Gain/Capacity Gain Calibration
15.2.2
Deadbands
15.2.2.1
Current Deadband
15.2.2.2
Coulomb Counter Deadband
15.2.3
Current Calibration Data Flash
15.3
Temperature Calibration
15.3.1
TS Calibration
15.3.2
Temperature Calibration Data Flash
15.3.3
Cell Temp Model
15.3.4
Internal Temp Model
16
Data Commands
16.1
Standard Data Commands
16.1.1
0x00/01 ManufacturerAccess()/ControlStatus()
16.1.2
0x02/03 AtRate()
16.1.3
0x04/05 AtRateTimeToEmpty()
16.1.4
0x06/07 Temperature()
16.1.5
0x08/09 Voltage()
16.1.6
0x0A/0B BatteryStatus()
16.1.7
0x0C/0D Current()
16.1.8
0x10/11 RemainingCapacity()
16.1.9
0x12/13 FullChargeCapacity()
16.1.10
0x14/15 AverageCurrent()
16.1.11
0x16/17 AverageTimeToEmpty()
16.1.12
0x18/19 AverageTimeToFull()
16.1.13
0x20/21 MaxLoadTimeToEmpty()
16.1.14
0x22/23 AveragePower()
16.1.15
0x28/29 InternalTemperature()
16.1.16
0x2A/2B CycleCount()
16.1.17
0x2C/2D RelativeStateOfCharge()—RSOC
16.1.18
0x2E/2F StateOfHealth()
16.1.19
0x30/31 ChargingVoltage()
16.1.20
0x32/33 ChargingCurrent()
16.1.21
0x34/35 TerminateVoltage()
16.1.22
0x36/0x37/0x38/0x39 Timestamp()
16.1.23
QMax Cycles() 0x3A/3B
16.1.24
0x3C/3D DesignCapacity()
16.1.25
0x3E/3F AltManufacturerAccess()
16.1.26
0x40/0x5F MACData()
16.1.27
0x60 MACDataChecksum()
16.1.28
0x61 MACDataLength()
16.2
0x00, 0x01 ManufacturerAccess() and 0x3E, 0x3F AltManufacturerAccess()
16.2.1
ManufacturerAccess() 0x0000
16.2.2
ManufacturerAccess() 0x0001 Device Type
16.2.3
ManufacturerAccess() 0x0002 Firmware Version
16.2.4
ManufacturerAccess() 0x0003 Hardware Version
16.2.5
ManufacturerAccess() 0x0004 Instruction Flash Signature
16.2.6
ManufacturerAccess() 0x0005 Static DF Signature
16.2.7
ManufacturerAccess() 0x0006 Chemical ID
16.2.8
ManufacturerAccess() 0x0008 Static Chem DF Signature
16.2.9
ManufacturerAccess() 0x0009 All DF Signature
16.2.10
ManufacturerAccess() 0x000A STORAGE Mode
16.2.11
ManufacturerAccess() 0x0010 SHUTDOWN Mode
16.2.12
ManufacturerAccess() 0x0011 SLEEP Mode
16.2.13
ManufacturerAccess() 0x001F CHG FET Toggle
16.2.14
ManufacturerAccess() 0x0020 DSG FET Toggle
16.2.15
ManufacturerAccess() 0x0021 Gauging
16.2.16
ManufacturerAccess() 0x0022 FET Control
16.2.17
ManufacturerAccess() 0x0023 Lifetime Data Collection
16.2.18
ManufacturerAccess() 0x0024 Permanent Failure
16.2.19
ManufacturerAccess() 0x0025 Black Box Recorder
16.2.20
ManufacturerAccess() 0x0028 Lifetime Data Reset
16.2.21
ManufacturerAccess() 0x0029 Permanent Fail Data Reset
16.2.22
ManufacturerAccess() 0x002A Black Box Recorder Reset
16.2.23
ManufacturerAccess() 0x002D CALIBRATION Mode
16.2.24
ManufacturerAccess() 0x002E Lifetime Data Flush
16.2.25
ManufacturerAccess() 0x002F Lifetime Data SPEED UP Mode
16.2.26
ManufacturerAccess() 0x0030 Seal Device
16.2.27
ManufacturerAccess() 0x0035 Security Keys
16.2.28
ManufacturerAccess() 0x0037 Authentication Key
16.2.29
ManufacturerAccess() 0x0041 Device Reset
16.2.30
ManufacturerAccess() 0x0050 SafetyAlert
16.2.31
ManufacturerAccess() 0x0051 SafetyStatus
16.2.32
ManufacturerAccess() 0x0052 PFAlert
16.2.33
ManufacturerAccess() 0x0053 PFStatus
16.2.34
ManufacturerAccess() 0x0054 OperationStatus
16.2.35
ManufacturerAccess() 0x0055 ChargingStatus
16.2.36
ManufacturerAccess() 0x0056 GaugingStatus
16.2.37
ManufacturerAccess() 0x0057 ManufacturingStatus
16.2.38
ManufacturerAccess() 0x0058 AFE Register
16.2.39
ManufacturerAccess() 0x005C VCT Voltage
16.2.40
ManufacturerAccess() 0x005E ChargingStatusExt
16.2.41
ManufacturerAccess() 0x0060 Lifetime Data Block 1
16.2.42
ManufacturerAccess() 0x0061 Lifetime Data Block 2
16.2.43
ManufacturerAccess() 0x0062 Lifetime Data Block 3
16.2.44
ManufacturerAccess() 0x0063 Lifetime Data Block 4
16.2.45
ManufacturerAccess() 0x0064 Lifetime Data Block 5
16.2.46
ManufacturerAccess() 0x0065 Lifetime Data Block 6
16.2.47
ManufacturerAccess() 0x0066 Lifetime Data Block 7
16.2.48
ManufacturerAccess() 0x0067 Lifetime Data Block 8
16.2.49
ManufacturerAccess() 0x0068 Lifetime Data Block 9
16.2.50
ManufacturerAccess() 0x0069 Lifetime Data Block 10
16.2.51
ManufacturerAccess() 0x006A Lifetime Data Block 11
16.2.52
ManufacturerAccess() 0x006B Lifetime Data Block 12
16.2.53
ManufacturerAccess() 0x006C Lifetime Data Block 13
16.2.54
ManufacturerAccess() 0x006D Lifetime Data Block 14
16.2.55
ManufacturerAccess() 0x006E Lifetime Data Block 15
16.2.56
ManufacturerAccess() 0x006F Power Events
16.2.57
ManufacturerAccess() 0x0070 ManufacturerInfo
16.2.58
ManufacturerAccess() 0x0071 DAStatus1
16.2.59
ManufacturerAccess() 0x0072 DAStatus2
16.2.60
ManufacturerAccess() 0x0073 GaugeStatus1
16.2.61
ManufacturerAccess() 0x0074 GaugeStatus2
16.2.62
ManufacturerAccess() 0x0075 GaugeStatus3
16.2.63
ManufacturerAccess() 0x0076 CBStatus
16.2.64
ManufacturerAccess() 0x0077 StateofHealth
16.2.65
ManufacturerAccess() 0x0078 FilterCapacity
16.2.66
ManufacturerAccess() 0x0079 RSOCWrite
16.2.67
ManufacturerAccess() 0x007A ManufacturerInfoB
16.2.68
ManufacturerAccess() 0x007B ManufacturerInfoC
16.2.69
ManufacturerAccess() 0x007E Lifetime Data Block 16
16.2.70
ManufacturerAccess() 0x0098 AccumulationChargeEnable
16.2.71
ManufacturerAccess() 0x0099 AccumulationDischargeEnable
16.2.72
ManufacturerAccess() 0x009A AccumulationReset
16.2.73
ManufacturerAccess() 0x009B AccumulationStop
16.2.74
ManufacturerAccess() 0x009C AccumulationStart
16.2.75
ManufacturerAccess() 0x009D AccumulationChargeThreshold
16.2.76
ManufacturerAccess() 0x009E AccumulationDischargeThreshold
16.2.77
ManufacturerAccess() 0x009F AccumulatedChargeTime
16.2.78
ManufacturerAccess() 0x00B0 ChargingVoltageOverride
16.2.79
ManufacturerAccess() 0x00B2 ChargingCurrentOverride
16.2.80
ManufacturerAccess() 0x00B4 RTC Access
16.2.81
ManufacturerAccess() 0x00B5 ChargerStatus
16.2.82
ManufacturerAccess() 0x00D2 ISI Current State
16.2.83
ManufacturerAccess() 0x00F0 IATAShutdown
16.2.84
ManufacturerAccess() 0x00F1 IATARm
16.2.85
ManufacturerAccess() 0x00F2 IATAFcc
16.2.86
ManufacturerAccess() 0x0F00 ROM Mode
16.2.87
ManufacturerAccess() 0x3008 WriteTemp
16.2.88
ManufacturerAccess() 0x4000–0x5FFF DataFlashAccess
16.2.89
ManufacturerAccess() 0xF080 and 0xF081 Output CCADCCal Control
16.2.90
ManufacturerAccess() 0xF082 OutputShortedCCADCCal
17
Data Flash Values
17.1
Settings
17.1.1
Configuration
17.1.1.1
Charging Configuration
17.1.1.2
Charging Configuration Ext
17.1.1.3
FET Options
17.1.1.4
SBS Gauging Configuration
17.1.1.5
SBS Configuration
17.1.1.6
Auth Config
17.1.1.7
Power Config
17.1.1.8
IO Config
17.1.1.9
Temperature Enable
17.1.1.10
Temperature Mode
17.1.1.11
DA Configuration
17.1.1.12
SOC Flag Config A
17.1.1.13
SOC Flag Config B
17.1.1.14
IT Gauging Configuration
17.1.1.15
IT Gauging Ext
17.1.1.16
Elevated Degrade Configuration
17.1.1.17
DZT Gauging Configuration
17.1.2
Flag Map
17.1.2.1
Set Up 1 Configuration
17.1.2.2
Set Up 1 Pin Number
17.1.2.3
Set Up 2 Configuration
17.1.2.4
Set Up 2 Pin Number
17.1.2.5
Set Up 3 Configuration
17.1.2.6
Set Up 3 Pin Number
17.1.2.7
Set Up 4 Configuration
17.1.2.8
Set Up 4 Pin Number
17.1.3
GPIO
17.1.3.1
Pres Pin Number
17.1.3.2
Disconnect Pin Number
17.1.3.3
Emergency Shutdown Pin Number
17.1.3.4
IO Shutdown Pin Number
17.1.3.5
BTP Pin Number
17.1.3.6
BTP Pin Configuration
17.1.3.7
GPIO_PF Pin Number
17.1.3.8
GPIO_INT Enable
17.1.3.9
GPIO_INT Output Enable
17.1.3.10
GPIO_INT Default Out
17.1.3.11
Sealed Access Config
17.1.4
BTP
17.1.4.1
Init Discharge Set
17.1.4.2
Init Charge Set
17.1.4.3
Init Charge SOC Set
17.1.4.4
Init Discharge SOC Set
17.1.5
Sealed Access
17.1.5.1
DF Only Read Timeout
17.1.5.2
MfgInfoC Write Timeout
17.1.6
Lifetimes
17.1.6.1
Lifetimes Configuration
17.1.6.2
Time RSOC Thresholds
17.1.6.3
Temperature Hold-off Time
17.1.6.4
Time Temperature Limits
17.1.7
Protection
17.1.7.1
Protection Configuration
17.1.7.2
Enabled Protections A
17.1.7.3
Enabled Protections B
17.1.7.4
Enabled Protections C
17.1.7.5
Enabled Protections D
17.1.8
Permanent Failure
17.1.8.1
Enabled PF A
17.1.8.2
Enabled PF B
17.1.8.3
Enabled PF C
17.1.8.4
Enabled PF D
17.1.9
AFE
17.1.9.1
OCC
17.1.9.2
OCD
17.1.9.3
Short Circuit Discharge
17.1.9.4
Under Voltage
17.1.9.5
Over Voltage
17.1.9.6
Current Charge Wake
17.1.9.7
Current Discharge Wake
17.1.9.8
OCC Delay
17.1.9.9
OCD Delay
17.1.9.10
Short Circuit Discharge Delay
17.1.9.11
Under Voltage Delay
17.1.9.12
Over Voltage Delay
17.1.9.13
Over Voltage Delay Hi
17.1.9.14
CD Wake Delay
17.1.9.15
CC Wake Delay
17.1.9.16
ZVCHG Exit Threshold
17.1.10
Smart Temperature
17.1.10.1
Mid Point Temp
17.1.11
Manufacturing
17.1.11.1
Manufacturing Status Init
17.1.12
Accumulated Charge Measurement
17.1.12.1
Accum Discharge Threshold
17.1.12.2
Accum Charge Threshold
17.2
Advanced Charging Algorithm
17.2.1
Minimum System Voltage
17.2.2
CHGR_DET Off Voltage
17.2.3
CHGR_DET On Voltage
17.2.4
Temperature Ranges
17.2.4.1
T1 Temp
17.2.4.2
Hysteresis Temp T1
17.2.4.3
T2 Temp
17.2.4.4
Hysteresis Temp T2
17.2.4.5
T5 Temp
17.2.4.6
Hysteresis Temp T5
17.2.4.7
T6 Temp
17.2.4.8
Hysteresis Temp T6
17.2.4.9
T3 Temp
17.2.4.10
Hysteresis Temp T3
17.2.4.11
T4 Temp
17.2.4.12
Hysteresis Temp T4
17.2.5
PreCharging
17.2.6
Maintenance Charging
17.2.7
Voltage Range
17.2.7.1
Precharge Start Voltage
17.2.7.2
Charging Voltage Low
17.2.7.3
Charging Voltage Med
17.2.7.4
Charging Voltage High
17.2.7.5
Charging Voltage Hysteresis
17.2.8
Degrade Mode 1
17.2.8.1
Cycle Threshold
17.2.8.2
SOH Threshold
17.2.8.3
Runtime Threshold
17.2.8.4
Voltage Degradation
17.2.8.5
Current Degradation
17.2.9
Degrade Mode 2
17.2.9.1
Cycle Threshold
17.2.9.2
SOH Threshold
17.2.9.3
Runtime Threshold
17.2.9.4
Voltage Degradation
17.2.9.5
Current Degradation
17.2.10
Degrade Mode 3
17.2.10.1
Cycle Threshold
17.2.10.2
SOH Threshold
17.2.10.3
Runtime Threshold
17.2.10.4
Voltage Degradation
17.2.10.5
Current Degradation
17.2.11
Degrade Mode
17.2.11.1
Runtime Degrade
17.2.11.2
Runtime Update Interval
17.2.11.3
Cycle Count Start Runtime
17.2.12
CS Degrade
17.2.12.1
Temperature Threshold
17.2.12.2
Voltage Threshold
17.2.12.3
Time Interval
17.2.12.4
Delta Voltage
17.2.12.5
Min CV
17.2.13
Charge Voltage Override
17.2.13.1
CHGV Override Max
17.2.13.2
CHGV Override Min
17.2.14
Charge Current Override
17.2.14.1
CHGI Override Max
17.2.14.2
CHGI Override Min
17.2.15
Termination Config
17.2.15.1
Charge Term Taper Current
17.2.15.2
Charge Term Voltage Offset
17.2.15.3
Charge Term Charging Voltage
17.2.16
Charging Rate of Change
17.2.16.1
Current Rate
17.2.16.2
Voltage Rate
17.2.17
Charge Loss Compensation
17.2.17.1
CCC Current Threshold
17.2.17.2
CCC Voltage Threshold
17.2.18
IR Correction
17.2.18.1
Averaging Interval
17.2.19
Sealed Write
17.2.19.1
Hold Off
17.2.19.2
Lockout
17.2.20
Low Temp Charging
17.2.20.1
Voltage
17.2.20.2
Current Low
17.2.20.3
Current Med
17.2.20.4
Current High
17.2.21
Standard Temp Low Charging
17.2.21.1
Voltage
17.2.21.2
Current Low
17.2.21.3
Current Med
17.2.21.4
Current High
17.2.22
Standard Temp High Charging
17.2.22.1
Voltage
17.2.22.2
Current Low
17.2.22.3
Current Med
17.2.22.4
Current High
17.2.23
High Temp Charging
17.2.23.1
Voltage
17.2.23.2
Current Low
17.2.23.3
Current Med
17.2.23.4
Current High
17.2.24
Rec Temp Charging
17.2.24.1
Voltage
17.2.24.2
Current Low
17.2.24.3
Current Med
17.2.24.4
Current High
17.2.25
Elevated Degrade
17.2.25.1
Accumulated ERM Time
17.2.25.2
Accumulated ERETM Time
17.2.25.3
Accumulated EVLTM Time
17.2.25.4
Accumulated EVMTM Time
17.2.25.5
Accumulated EVHTM Time
17.2.25.6
ERETM Status
17.2.25.7
EVTM Degrade
17.2.25.8
EVTM Active
17.2.25.9
ERM Reset RSoC Threshold
17.2.25.10
ERM Reset Voltage Threshold
17.2.25.11
ERM RSoC Threshold
17.2.25.12
ERM Voltage Threshold
17.2.25.13
ERM Time Threshold
17.2.25.14
ERETM RSoC Threshold
17.2.25.15
ERETM Voltage Threshold
17.2.25.16
ERETM Temperature Threshold
17.2.25.17
ERETM Time Threshold
17.2.25.18
ERETM Charging Voltage
17.2.25.19
EVTM Voltage Thresholds
17.2.25.20
EVTM Temperature Thresholds
17.2.25.21
EVLTM Time Thresholds
17.2.25.22
EVLTM Delta Charging Voltages
17.2.25.23
EVMTM Time Thresholds
17.2.25.24
EVMTM Delta Charging Voltages
17.2.25.25
EVHTM Time Thresholds
17.2.25.26
EVHTM Delta Charging Voltages
17.3
Power
17.3.1
Power
17.3.2
Shutdown
17.3.2.1
Shutdown Voltage
17.3.2.2
Shutdown Time
17.3.2.3
IO Shutdown Delay
17.3.2.4
IO Shutdown Timeout
17.3.2.5
Low RSoC Shutdown Threshold
17.3.2.6
Low RSoC Shutdown Time
17.3.2.7
Charger Present Threshold
17.3.3
Sleep
17.3.3.1
Sleep Current
17.3.3.2
Low Current
17.3.3.3
Low Current Period
17.3.3.4
Measure Time
17.3.3.5
Bus Timeout
17.3.3.6
Current Time
17.3.4
Ship
17.3.4.1
FET Off Time
17.3.4.2
Delay
17.3.4.3
Auto Ship Time
17.3.5
Power Off
17.3.6
Manual FET Control
17.3.7
System Present
17.3.7.1
SysPres Delay
17.3.8
Storage
17.3.8.1
Storage Delay
17.3.8.2
Storage Ignore SMB Delay
17.3.9
Power Events
17.3.9.1
Power Events
17.3.10
IATA
17.3.10.1
IATA Config
17.3.10.2
IATA Delay Time
17.3.10.3
IATA RSOC Threshold
17.3.10.4
IATA Wake AbsRSOC
17.3.10.5
IATA MIN Temperature
17.3.10.6
IATA MAX Temperature
17.3.10.7
IATA MIN Voltage
17.3.10.8
IATA MAX Voltage
17.3.11
IATA STORE
17.3.11.1
IATA RM mAH
17.3.11.2
IATA RM cWH
17.3.11.3
IATA FCC mAH
17.3.11.4
IATA FCC cWH
17.3.11.5
IATA Flag
17.3.12
Unintended Wakeup
17.3.12.1
Delay
17.3.12.2
Count
17.4
System Data
17.4.1
Manufacturer Info
17.4.2
Manufacturer Info B
17.4.3
Manufacturer Info C
17.4.4
Integrity
17.4.4.1
Static DF Signature
17.4.4.2
Static Chem DF
17.4.4.3
All DF Signature
17.5
SBS Configuration
17.5.1
Data
17.5.1.1
Manufacturer Date
17.5.1.2
Serial Number
17.5.1.3
Manufacturer Name
17.5.1.4
Device Name
17.5.1.5
Device Chemistry
17.5.1.6
Remaining Capacity Alarm
17.5.1.6.1
Remaining Ah Capacity Alarm
17.5.1.6.2
Remaining Wh Capacity Alarm
17.5.1.7
RemainingTimeAlarm
17.5.1.8
Initial Battery Mode
17.5.1.9
Specification Information
17.5.1.10
VLB Remaining Capacity
17.5.1.10.1
VLB Remaining Cap mAh
17.5.1.10.2
VLB Remaining Cap in cWh
17.5.1.11
VLB Voltage
17.5.1.12
VLB Hold Time
17.5.1.13
VLB Timeout
17.6
Lifetimes
17.6.1
Cell 1 Max Voltage
17.6.2
Cell 1 Min Voltage
17.6.3
Current
17.6.3.1
Max Charge Current
17.6.3.2
Max Discharge Current
17.6.3.3
Max Avg Dsg Current
17.6.3.4
Max Avg Dsg Power
17.6.4
Temperature-Relax
17.6.4.1
Max Temp Cell
17.6.4.2
Min Temp Cell
17.6.4.3
Min Temp Int Sensor
17.6.4.4
Max Temp Int Sensor
17.6.4.5
Max Temp Fet
17.6.4.6
Max Temp TS1
17.6.4.7
Min Temp TS1
17.6.5
Max Temp Cell
17.6.6
Min Temp Cell
17.6.7
Max Temp Int Sensor
17.6.8
Min Temp Int Sensor
17.6.9
Max Temp Fet
17.6.10
Max Temp TS1
17.6.11
Min Temp TS1
17.6.12
Max Temp Cell
17.6.13
Min Temp Cell
17.6.14
Max Temp Int Sensor
17.6.15
Min Temp Int Sensor
17.6.16
Max Temp Fet
17.6.17
Max Temp TS1
17.6.18
Min Temp TS1
17.6.19
Safety Events
17.6.19.1
No Of COV Events
17.6.19.2
Last COV Event
17.6.19.3
No Of CUV Events
17.6.19.4
Last CUV Event
17.6.19.5
No Of OCD1 Events
17.6.19.6
Last OCD1 Event
17.6.19.7
No Of OCD2 Events
17.6.19.8
Last OCD2 Event
17.6.19.9
No Of OCC1 Events
17.6.19.10
Last OCC1 Event
17.6.19.11
No Of OCC2 Events
17.6.19.12
Last OCC2 Event
17.6.19.13
No Of AOCD Events
17.6.19.14
Last AOCD Event
17.6.19.15
No Of ASCD Events
17.6.19.16
Last ASCD Event
17.6.19.17
No Of AOCC Events
17.6.19.18
Last AOCC Event
17.6.19.19
No Of OTC Events
17.6.19.20
Last OTC Event
17.6.19.21
No Of OTD Events
17.6.19.22
Last OTD Event
17.6.19.23
No Of OTF Events
17.6.19.24
Last OTF Event
17.6.20
Charging Events
17.6.20.1
No Valid Charge Term
17.6.20.2
Last Valid Charge Term
17.6.21
Gauging Events
17.6.21.1
No Of Qmax Updates
17.6.21.2
Last Qmax Update
17.6.21.3
No Of Ra Updates
17.6.21.4
Last Ra Update
17.6.21.5
No Of Ra Disable
17.6.21.6
Last Ra Disable
17.6.22
Time
17.6.22.1
Total Firmware Runtime
17.6.22.2
Time Spent in LFT_UUT
17.6.22.3
Time Spent in LFT_UT
17.6.22.4
Time Spent in LFT_LT
17.6.22.5
Time Spent in LFT_STL
17.6.22.6
Time Spent in LFT_RT
17.6.22.7
Time Spent in LFT_STH
17.6.22.8
Time Spent in LFT_HT
17.6.22.9
Time Spent in LFT_OT
17.7
Protections
17.7.1
CUV—Cell Undervoltage
17.7.1.1
Threshold
17.7.1.2
Delay
17.7.1.3
Recovery
17.7.1.4
Recovery Charger Present Time
17.7.2
CUVC—Cell Undervoltage
17.7.2.1
Threshold
17.7.2.2
Delay
17.7.2.3
Recovery
17.7.3
ACUV—Cell Under Voltage hardware based
17.7.3.1
Recovery (ACUV)
17.7.4
ACOV—Cell Over Voltage hardware based
17.7.4.1
Recovery (ACOV)
17.7.5
COV—Cell Overvoltage
17.7.5.1
Threshold Low Temp
17.7.5.2
Threshold Standard Temp Low
17.7.5.3
Threshold Standard Temp High
17.7.5.4
Threshold High Temp
17.7.5.5
Threshold Rec Temp
17.7.5.6
Delay
17.7.5.7
Recovery Low Temp
17.7.5.8
Recovery Standard Temp Low
17.7.5.9
Recovery Standard Temp High
17.7.5.10
Recovery High Temp
17.7.5.11
Recovery Rec Temp
17.7.5.12
Cell Overvoltage Latch Limit
17.7.5.13
Cell Overvoltage Counter Decrement Delay
17.7.5.14
Reset
17.7.6
OCC1—Overcurrent In Charge 1
17.7.6.1
Threshold
17.7.6.2
Delay
17.7.7
OCC2—Overcurrent In Charge 2
17.7.7.1
Threshold
17.7.7.2
Delay
17.7.8
OCC—Overcurrent In Charge Recovery
17.7.8.1
Recovery Threshold
17.7.8.2
Recovery Delay
17.7.9
OCD1—Overcurrent In Discharge 1
17.7.9.1
Threshold
17.7.9.2
Delay
17.7.10
OCD2—Overcurrent In Discharge 2
17.7.10.1
Threshold
17.7.10.2
Delay
17.7.11
OCD—Overcurrent In Discharge Recovery
17.7.11.1
Recovery Threshold
17.7.11.2
Recovery Delay
17.7.11.3
Latch Limit
17.7.11.4
Counter Dec Delay
17.7.11.5
Reset
17.7.12
AOCD—Overload in Discharge
17.7.12.1
Latch Limit
17.7.12.2
Counter Dec Delay
17.7.12.3
Recovery
17.7.12.4
Reset
17.7.13
AOCC—Overcurrent In Charge
17.7.13.1
Latch Limit
17.7.13.2
Counter Dec Delay
17.7.13.3
Recovery
17.7.13.4
Reset
17.7.14
ASCD—Short Circuit in Discharge
17.7.14.1
Latch Limit
17.7.14.2
Counter Dec Delay
17.7.14.3
Recovery
17.7.14.4
Reset
17.7.15
OTC—Overtemperature in Charge
17.7.15.1
Threshold
17.7.15.2
Delay
17.7.15.3
Recovery
17.7.16
OTD—Overtemperature in Discharge
17.7.16.1
Threshold
17.7.16.2
Delay
17.7.16.3
Recovery
17.7.17
OTF—Overtemperature FET
17.7.17.1
Threshold
17.7.17.2
Delay
17.7.17.3
Recovery
17.7.18
UTC—Undertemperature in Charge
17.7.18.1
Threshold
17.7.18.2
Delay
17.7.18.3
Recovery
17.7.19
UTD—Undertemperature in Discharge
17.7.19.1
Threshold
17.7.19.2
Delay
17.7.19.3
Recovery
17.7.20
HWD—Host Watchdog
17.7.21
PTO—PRECHARGE Mode Time Out
17.7.21.1
Charge Threshold
17.7.21.2
Suspend Threshold
17.7.21.3
Delay
17.7.21.4
Reset
17.7.22
CTO—Fast Charge Mode Time Out
17.7.22.1
Charge Threshold
17.7.22.2
Suspend Threshold
17.7.22.3
Delay
17.7.22.4
Reset
17.7.23
OC—Overcharge
17.7.23.1
Threshold
17.7.23.2
Recovery
17.7.23.3
RSOC Recovery
17.7.24
CHGV—ChargingVoltage
17.7.24.1
Threshold
17.7.24.2
Delay
17.7.24.3
Recovery
17.7.25
CHGC—ChargingCurrent
17.7.25.1
Threshold
17.7.25.2
Delay
17.7.25.3
Recovery Threshold
17.7.25.4
Recovery Delay
17.7.26
PCHGC—Pre-ChargingCurrent
17.7.26.1
Threshold
17.7.26.2
Delay
17.7.26.3
Recovery Threshold
17.7.26.4
Recovery Delay
17.8
Permanent Fail
17.8.1
SUV—Safety Cell Undervoltage
17.8.1.1
Threshold
17.8.1.2
Delay
17.8.2
SOV—Safety Cell Overvoltage
17.8.2.1
Threshold
17.8.2.2
Delay
17.8.3
SOCC—Safety Overcurrent in Charge
17.8.3.1
Threshold
17.8.3.2
Delay
17.8.4
SOCD—Safety Overcurrent in Discharge
17.8.4.1
Threshold
17.8.4.2
Delay
17.8.5
SOT—Overtemperature Cell
17.8.5.1
SOTC Threshold
17.8.5.2
SOTC Delay
17.8.5.3
SOTD Threshold
17.8.5.4
SOTD Delay
17.8.6
SOTF—Overtemperature FET
17.8.6.1
Threshold
17.8.6.2
Delay
17.8.7
CD—Capacity Degradation
17.8.7.1
Threshold
17.8.7.2
Delay
17.8.8
CFET—CHG FET Failure
17.8.8.1
OFF Threshold
17.8.8.2
OFF Delay
17.8.9
DFET—DFET Failure
17.8.9.1
OFF Threshold
17.8.9.2
OFF Delay
17.8.10
AFER—AFE Register
17.8.10.1
Threshold
17.8.10.2
Delay Period
17.8.10.3
Compare Period
17.8.11
AFEC—AFE Communication
17.8.11.1
Threshold
17.8.11.2
Delay Period
17.9
PF Status
17.9.1
Device Status Data
17.9.1.1
Safety Alert A
17.9.1.2
Safety Status A
17.9.1.3
Safety Alert B
17.9.1.4
Safety Status B
17.9.1.5
Safety Alert C
17.9.1.6
Safety Status C
17.9.1.7
Safety Alert D
17.9.1.8
Safety Status D
17.9.1.9
PF Alert A
17.9.1.10
PF Status A
17.9.1.11
PF Alert B
17.9.1.12
PF Status B
17.9.1.13
PF Alert C
17.9.1.14
PF Status C
17.9.1.15
PF Alert D
17.9.1.16
PF Status D
17.9.1.17
Fuse Flag
17.9.1.18
Operation Status A
17.9.1.19
Operation Status B
17.9.1.20
Temp Range
17.9.1.21
Charging Status A
17.9.1.22
Charging Status B
17.9.1.23
Gauging Status
17.9.1.24
IT Status
17.9.2
Device Voltage Data (at the Time of PF Event)
17.9.2.1
Cell 1 Voltage
17.9.2.2
Battery Direct Voltage
17.9.2.3
Pack Voltage
17.9.3
Device Current Data
17.9.4
Device Gauging Data (at the Time of PF Event)
17.9.4.1
Cell 1DOD0
17.9.4.2
Passed Charge
17.9.5
AFE Regs
17.9.5.1
OCC
17.9.5.2
OCD1
17.9.5.3
OCD2
17.9.5.4
Short Circuit Discharge
17.9.5.5
Current Discharge Wake
17.9.5.6
Current Charge Wake
17.9.5.7
OCC 1 Delay 2
17.9.5.8
OCC 1 Delay 1
17.9.5.9
OCD 1 Delay 2
17.9.5.10
OCD 1 Delay 1
17.9.5.11
OCD 2 Delay 2
17.9.5.12
OCD 2 Delay 1
17.9.5.13
Short Circuit Discharge Delay
17.9.5.14
Over Temperature Delay
17.9.5.15
OCD Wake Delay 2
17.9.5.16
OCD Wake Delay 1
17.9.5.17
OCC Wake Delay 2
17.9.5.18
OCC Wake Delay 1
17.10
Black Box
17.10.1
Safety Status
17.10.2
PF Status
17.11
Gas Gauging
17.11.1
Current Thresholds
17.11.1.1
Dsg Current Threshold
17.11.1.2
Chg Current Threshold
17.11.1.3
Quit Current
17.11.1.4
Dsg Relax Time
17.11.1.5
Chg Relax Time
17.11.2
Design
17.11.2.1
Design Capacity mAh
17.11.2.2
Design Capacity cWh
17.11.2.3
Design Voltage
17.11.3
Cycle
17.11.4
FD
17.11.4.1
Set Voltage Threshold
17.11.4.2
Clear Voltage Threshold
17.11.4.3
Set % RSOC Threshold
17.11.4.4
Clear % RSOC Threshold
17.11.5
FC
17.11.5.1
Set Voltage Threshold
17.11.5.2
Clear Voltage Threshold
17.11.5.3
Set % RSOC Threshold
17.11.5.4
Clear % RSOC Threshold
17.11.6
TD
17.11.6.1
Set Voltage Threshold
17.11.6.2
Clear Voltage Threshold
17.11.6.3
Set % RSOC Threshold
17.11.6.4
Clear % RSOC Threshold
17.11.7
TC
17.11.7.1
Set Voltage Threshold
17.11.7.2
Clear Voltage Threshold
17.11.7.3
Set % RSOC Threshold
17.11.7.4
Clear % RSOC Threshold
17.11.8
State
17.11.8.1
QMax
17.11.8.2
Update Status
17.11.8.3
Cell 1 Chg Voltage at EoC
17.11.8.4
Current at EoC
17.11.8.5
Average Last Run
17.11.8.5.1
Avg I Last Run
17.11.8.5.2
Avg P Last Run
17.11.8.6
Delta Voltage
17.11.8.7
Temp
17.11.8.7.1
Temp k
17.11.8.7.2
Temp a
17.11.8.8
Max Avg Last Run
17.11.8.8.1
Max Avg I Last Run
17.11.8.8.2
Max Avg P Last Run
17.11.8.9
SOH FCC Max
17.11.8.9.1
SOH FCC Max mAh
17.11.8.9.2
SOH FCC Max cWh
17.11.8.10
SOH Temp
17.11.8.10.1
SOH Temp k
17.11.8.10.2
SOH Temp a
17.11.8.11
Cycle Count
17.11.9
Turbo Cfg
17.11.9.1
Min System Voltage
17.11.9.2
Ten Second Max C-Rate
17.11.9.3
Ten Millisecond Max C-Rate
17.11.9.4
High Frequency Resistance
17.11.9.5
Reserve Energy %
17.11.9.6
Turbo Adjustment Factor
17.11.10
IT-DZT Config
17.11.10.1
Design Resistance
17.11.10.2
Pack Resistance
17.11.10.3
System Resistance
17.11.10.4
Predict Ambient Time
17.11.10.5
Ra Filter
17.11.10.6
Ra Max Delta
17.11.10.7
Reference Grid
17.11.10.8
Resistance Parameter Filter
17.11.10.9
Near EDV Ra Param Filter
17.11.10.10
Max Current Change %
17.11.10.11
Resistance Update Voltage
17.11.10.12
Qmax Delta
17.11.10.13
Qmax Upper Bound
17.11.10.14
Term Voltage
17.11.10.15
Res Relax Time
17.11.10.16
Term Voltage Delta
17.11.10.17
Max Simulation Iterations
17.11.10.18
Simulation Near Term Delta
17.11.10.19
Fast Scale Start SOC
17.11.10.20
DeltaV Max Voltage Delta
17.11.10.21
Load Select
17.11.10.22
Fast Scale Load Select
17.11.10.23
Load Mode
17.11.10.24
User Rate-mA
17.11.10.25
User Rate-cW
17.11.10.26
Reserve Cap-mAh
17.11.10.27
Reserve Cap-cWh
17.11.11
Smoothing
17.11.11.1
Smooth Relax Time
17.11.11.2
Term Smooth Start Cell V Delta
17.11.11.3
Term Smooth Final Cell V Delta
17.11.11.4
Term Smooth Time
17.11.12
Condition Flag
17.11.13
Max Error
17.11.13.1
Time Cycle Equivalent
17.11.13.2
Cycle Delta
17.11.14
SOH
17.12
RA Table
17.12.1
R_a0
17.12.2
R_a0x
18
Data Flash Access and Format
18.1
Data Flash Access
18.1.1
Minimum Voltage
18.2
Data Formats
18.2.1
Unsigned Integer
18.2.2
Integer
18.2.3
Floating Point
18.2.4
Hex
18.2.5
String
19
Data Flash Summary
19.1
Data Flash Summary - Subject to Change upon FW build details
20
Revision History
Technical Reference Manual
BQ27Z855