What the BQ27530YZFT-G1 does in the pack
The BQ27530YZFT-G1 is a single-cell Li-Ion battery fuel gauge from TI's Impedance Track™ series, reporting remaining capacity and state-of-charge over an I²C bus. The algorithm compensates for discharge rate, temperature, and cell aging — a step up from coulomb-counters that drift without periodic full-learning cycles. The 15-DSBGA package (0.5 mm pitch, wafer-level chip-scale) keeps the footprint under 3 mm², but the exposed bumps demand a clean solder-paste stencil and a controlled reflow profile — no hand-soldering.
Single-cell limit and chemistry match
This gauge is designed for one Li-Ion series cell only — the BQ27530YZFT-G1 cannot monitor a 2-series stack or LiFePO4 chemistry without external level shifting and a different algorithm profile. For multi-cell packs, the BQ2084DBT-V143 handles 2 to 4 series cells via SMBus, though its temperature range tops out at 85°C and it comes in a larger TSSOP package. The Impedance Track™ engine learns the cell's internal resistance over time, so swapping to a different Li-Ion cell vendor requires a fresh learning cycle or a pre-loaded golden image.