Single cell Li-ion battery fuel gauge for battery pack Integration; FW upgrade to BQ27541



Product details


Cell chemistry Li-Ion/Li-Polymer Number of series cells Single Cell Communication interface HDQ, I2C Battery capacity (Min) (mAh) 300 Battery capacity (Max) (mAh) 8000 Implementation Pack External capacity indication None Features Impedance Track™ algorithm, SHA-1 Authentication Operating temperature range (C) -40 to 85 Cell balancing open-in-new Find other Battery fuel gauges

Package | Pins | Size

VSON (DRZ) 12 10 mm² 4 x 2.5 open-in-new Find other Battery fuel gauges


  • Battery Fuel Gauge for 1-Series
    Li-Ion Applications
  • Microcontroller Peripheral Provides:
    • Accurate Battery Fuel Gauging
    • Internal Temperature Sensor for
      System Temperature Reporting
    • SHA-1/HMAC Authentication
    • Lifetime Data Logging
    • 96 Bytes of Non-Volatile Scratch
      Pad FLASH
  • Battery Fuel Gauging Based on Patented
    Impedance Track Technology
    • Models Battery Discharge Curve for
      Accurate Time-To-Empty Predictions
    • Automatically Adjusts for Battery Aging,
      Battery Self-Discharge, and Temperature/
      Rate Inefficiencies
    • Low-Value Sense Resistor (5mΩ to 20mΩ)
  • HDQ and I2C Interface Formats
    for Communication With Host System
  • Small 12-pin 2.5 mm × 4 mm SON Package
    • Smartphones
    • PDAs
    • Digital Still and Video Cameras
    • Handheld Terminals
    • MP3 or Multimedia Players

open-in-new Find other Battery fuel gauges


The Texas Instruments bq27541 Li-Ion battery fuel gauge is a microcontroller peripheral that provides fuel gauging for single-cell Li-Ion battery packs. The device requires little system microcontroller firmware development for accurate battery fuel gauging. The bq27541 resides within the battery pack or on the system’s main-board with an embedded battery (nonremovable).

The bq27541 uses the patented Impedance Track™ algorithm for fuel gauging, and provides information such as remaining battery capacity (mAh), state-of-charge (%), run-time to empty (min.), battery voltage (mV), and temperature (°C).

The bq27541 also features integrated support for secure battery pack authentication, using the SHA-1/HMAC authentication algorithm.

open-in-new Find other Battery fuel gauges

Technical documentation

star = Top documentation for this product selected by TI
No results found. Please clear your search and try again.
View all 23
Type Title Date
* Data sheet Single Cell Li-Ion Battery Fuel Gauge for Battery-Pack Integration datasheet (Rev. B) Sep. 19, 2013
Application note Achieving The Successful Learning Cycle Jun. 19, 2018
Application note Using I2C Communication With the bq275xx Series of Fuel Gauges (Rev. B) May 15, 2014
Application note bq27541-v200 to bq27541-G1 Change List (Rev. A) Oct. 21, 2012
Application note Thermistor Selection Guide for Texas Instruments Advanced Fuel Gauges Sep. 28, 2011
Application note WinCE/Linux Drivers for bq275xx Fuel Gauge Mar. 17, 2011
Application note Fine tuning TI's Impedance Track™ battery fuel gauge with LiFePO4 cells Mar. 14, 2011
Application note Going to Production With the bq2754x (Rev. A) Mar. 11, 2011
Application note Configuring the bq27541-V200 Data Flash (Rev. B) Mar. 09, 2011
Application note Updating bq275xx Firmware at Production (Rev. A) Feb. 21, 2011
Application note bq27541 to bq27541-v200 Change List Feb. 17, 2010
Application note How to Generate Golden Image for Single-Cell Impedance Track(TM) Devices Jan. 07, 2010
Application note Configuring the bq2754x Data Flash May 27, 2009
Application note Improving Battery Safety, Charging, and Fuel Gauging in Portable Media Apps Mar. 11, 2009
Application note Single Cell Gas Gauge Application Book Jul. 28, 2008
Application note Updating Firmware with the bq2750x and EVM. (Rev. A) Jul. 22, 2008
Application note Impedance Track Fuel Gauge Accuracy Test for GSM Phone Applications Mar. 21, 2008
Application note ESD and RF Mitigation in Handheld Battery Pack Electronics Mar. 06, 2008
Application note Single Cell Gas Gauge Circuit Design Feb. 22, 2008
Application note Single Cell Impedance Track Printed-Circuit Board Layout Feb. 22, 2008
Application note Theory and Implementation of Impedance Track Battery Fuel-Gauging Algorithm Jan. 31, 2008
Application note Host-Side Gas-Gauge-System Design Considerations for Single-Cell Handheld Apps Oct. 12, 2007
White paper Impedance Track Based Fuel Gauging Sep. 27, 2007

Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Hardware development

document-generic User guide

This evaluation module (EVM) is a complete evaluation system for the bq27541. The EVM includes one bq27541 circuit module, a current sense resistor, one thermistor, an EV2300 personal computer (PC) interface board for gas gauge interface, a PC USB cable, and Windows™-based PC software. The (...)

  • Complete evaluation system for the bq27541 gas gauge with Impedance Track™ Technology
  • Populated circuit module for quick setup
  • PC software and interface board for easy evaluation
  • Software that allows data logging for system analysis

Software development

SLUC174.ZIP (46 KB)
SLUC261HY.ZIP (496964 KB)
SLUC367C.ZIP (63861 KB)
SLUC368A.ZIP (47 KB)

Design tools & simulation

SLUC138DJ.ZIP (6840 KB)

Reference designs

Energy Harvesting Reference Design Solution for Ultra Low Power Boost Converter IC
TIDA-00041 This reference design is an ultra low power boost converter for energy harvesting Applications. This solution is programmed from the factory for settings compatible with most MCU’s and 3V coin cell batteries. The design is programmed to deliver a 3.1VDC maximum voltage (OV) for charging the (...)
document-generic Schematic document-generic User guide

CAD/CAE symbols

Package Pins Download
SON (DRZ) 12 View options

Ordering & quality

Information included:
  • RoHS
  • Device marking
  • Lead finish/Ball material
  • MSL rating/Peak reflow
  • MTBF/FIT estimates
  • Material content
  • Qualification summary
  • Ongoing reliability monitoring

Recommended products may have parameters, evaluation modules or reference designs related to this TI product.

Support & training

TI E2E™ forums with technical support from TI engineers

Content is provided "as is" by TI and community contributors and does not constitute TI specifications. See terms of use.

If you have questions about quality, packaging or ordering TI products, see TI support. ​​​​​​​​​​​​​​