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 for Single- and Multi-Cell Lithium Primary (Non-Rechargeable) Batteries
  • Supports Lithium Thionyl Chloride (Li-SOCl2) and Lithium Manganese Dioxide (Li-MnO2) Chemistries
  • Provides Three Configurable Algorithm Options:
    • State-Of-Health (SOH)
    • End-Of-Service (EOS)
    • Coulomb Accumulation (ACC)
  • Ultra-Low Average Power Consumption Supported Through Gauge-Enable Control
  • Accurate Voltage, Temperature, Current, and Coulomb Counter Measurements
  • I2C™ Host Communication, Providing Battery Parameter and Status Access
  • Configurable Host Interrupt
  • Battery Information Data Logging Options
  • SHA-1 Authentication

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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