BQ35100 Lithium Primary Battery Fuel Gauge and End-of-Service Monitor |

BQ35100 (ACTIVE)

Lithium Primary Battery Fuel Gauge and End-of-Service Monitor

Lithium Primary Battery Fuel Gauge and End-of-Service Monitor - BQ35100


The bq35100 Battery Fuel Gauge and End-Of-Service Monitor provides highly configurable fuel gauging for non-rechargeable (primary) lithium batteries without requiring a forced discharge of the battery. Built so that optimization is not necessary to achieve accurate gauging, the bq35100 device uses patented TI gauging algorithms to support the option to seamlessly replace an old battery with a new one.

The bq35100 device provides accurate results with ultra-low average power consumption where less than 2 µA can be achieved through host control via the GAUGE ENABLE (GE) pin. The device is only required to be powered long enough, at a system-determined update frequency, to gather data and to make calculations to support the selected algorithm. A typical system may need to only be updated once every 8 hours as the gauge is not required to be powered to measure all discharge activity.

The fuel gauging functions use voltage, current, and temperature measurements to provide State-Of-Health (SOH) data and End-Of-Service (EOS) warning information where the host can read the gathered data through a 400-kHz I2C bus. An ALERT output, based on a variety of configurable status and data options, is also available to interrupt the host.


  • Fuel Gauge and Battery Diagnostics for Flow Meter Applications Predict End-of-Service or Early Battery Failure
    • Supports Lithium Thionyl Chloride (Li-SOCl2) and Lithium Manganese Dioxide (Li-MnO2) Chemisty Batteries
    • Accurate Voltage, Temperature, Current, and Coulomb Counter Measurements that Report Battery Health and Service Life
    • State-Of-Health (SOH) Algorithm for Li-MnO2
    • End-Of-Service (EOS Algorithm for Li-SOCl2)
    • Coulomb Accumulation (ACC) Algorithm for All Battery Types
  • Ultra-Low Average Power Consumption to Maximize Battery Run Time
    • Gauge Enabled Through Host-Controlled Periodic Updates
    • State-Of-Health (SOH) ~0.06 µA
    • End-Of-Service (EOS) ~0.35 µA
    • Coulomb Accumulation (ACC) Diagnostic Updates ~0.3 µA
  • System Interaction Capabilities
    • I2C Host Communication, Providing Battery Parameter and Status Access
    • Configurable Host Interrupt
    • Battery Information Data Logging Options for in Operation Diagnostics and Failure Analysis
    • SHA-1 Authentication to Help Prevent Counterfeit Battery Use

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Parametrics Compare all products in Battery Fuel Gauge

Number of Series Cells
Cell Chemistry
Battery Capacity (Max) (mAh)
Communication Interface
Battery Capacity (Min) (mAh)
External Capacity Indication
Gas Gauge Algorithm
Cell Balancing
Operating Temperature Range (C)
BQ35100 BQ27220 BQ27426 BQ27520-G4 BQ27542-G1 BQ27621-G1
2-4 Cells
>4 Cells
Single Cell    
Single Cell     Single Cell     Single Cell     Single Cell     Single Cell    
Primary Lithium     Li-Ion/Li-Polymer     Li-Ion/Li-Polymer     Li-Ion/Li-Polymer     Li-Ion/Li-Polymer     Li-Ion/Li-Polymer    
32000     29000     14000     32000     32000     32000    
I2C     I2C     I2C     I2C     HDQ
100     100     100     100     100     100    
None     None     None     None     None     None    
System     System     Pack     System    
Primary     CEDV     Impedance Track     Impedance Track     Impedance Track     Dynamic Voltage Correlation    
N/A     N/A     N/A     N/A     N/A     N/A    
End of Service     N/A     N/A     N/A     SHA-1 Authentication     No Sense Resistor Required    
-40 to 85     -40 to 85     -40 to 85     -40 to 85     -40 to 85     -40 to 85    
14TSSOP     9DSBGA     9DSBGA     15DSBGA     12SON     9DSBGA