Single-cell Li-Ion fuel gauge with Impedance Track
The Texas Instruments BQ27501DRZT is a battery monitor IC from the Impedance Track series, designed for single-cell Lithium Ion packs. It uses TI's proprietary Impedance Track algorithm to report state-of-charge with better accuracy than simple voltage-based gauges, compensating for cell aging, temperature, and discharge rate. Communication with a host microcontroller is over an I²C interface.
Industrial temperature range and package
It comes in a 12-VFDFN Exposed Pad package (12-SON 2.5x4 mm), surface-mount only.
Active lifecycle — no last-time-buy pressure
The base product number is BQ27501.
Fault protection and chemistry support
Built-in over-temperature fault protection monitors the battery pack. The gauge is optimized for Lithium Ion chemistry only — it does not support LiFePO4 or other chemistries out of the box, so a chemistry-specific gauge or a reconfiguration via the Impedance Track profile would be needed for non-Li-Ion cells.