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Bq40370 Site

is a specialized, proprietary battery fuel gauge and protection integrated circuit (IC) developed by Texas Instruments

This is the most active community for this specific chip. You can find threads on unsealing Dell WDX0R batteries and troubleshooting RSOC (Relative State of Charge) "jumps" Texas Instruments Support: bq40370

4. Recommendations

To resolve the identity of bq40370, consider the following actions: is a specialized, proprietary battery fuel gauge and

  1. Medical Ventilators & Infusion Pumps: The impedance tracking ensures that "30% battery" does not become "0% abruptly" during a critical procedure.
  2. Cordless Power Tools (High End): DeWalt and Milwaukee have used variants of this chip (or its firmware-locked OEM versions) in 18V/20V Max packs. It allows the tool to "throttle down" before shutting off completely.
  3. Robotic Vacuums: High-end Roomba models (similar to iRobot’s BMS designs) leverage the bq40370 for multi-cell Li-ion packs.
  4. E-bike Batteries: Smaller form-factor e-bike batteries (36V, 10s packs require multiple chips, but 4s packs use single bq40370).

Introduction