Fuel gauge for a single Li-ion cell
It reports state-of-charge, voltage, and current for one series cell — typical in handheld medical devices, power tools, and portable instruments where the pack is a single Li-ion or Li-Polymer cell.
The BQ27426YZFR ships in a 9-ball DSBGA wafer-level package. That footprint requires a controlled solder-paste stencil and X-ray inspection after reflow — not a hand-solderable part. No through-hole alternative exists in this series.
TI lists the BQ27426YZFR as Active on its product lifecycle status. No last-time-buy or end-of-life notice has been issued. ROHS3 compliant. For new designs, this part is a current, supported choice — no forced redesign horizon.
Peer comparison — cell count and temperature grade
The BQ79612PAPRQ1 is an automotive-grade (AEC-Q100) monitor with SPI/UART interface, but it also handles a single cell and adds fault protection. Its temperature range extends to 125°C — suitable for underhood environments, while the BQ27426 stays at 85°C. The BQ2084DBT-V143 supports 2 to 4 cells via SMBus and is limited to -20°C to 85°C, so it fits multi-cell packs but not extended cold. Neither is a drop-in replacement — the interface, package, and cell count differ.