Bq40370 ((link)) Review

The bq40370 is a specific battery fuel gauge chip, primarily found in Dell laptop batteries (such as the WDX0R and PW23Y models). Because it is a "custom" Texas Instruments chip, there is no public official datasheet, which has led to a community-driven body of "articles" and forum guides focused on unlocking and repairing it. Key Community Articles and Resources

The bq40370 is a specialized battery fuel gauge chip developed by Texas Instruments (TI), commonly found in laptop battery packs such as those for Dell (e.g., model WDX0R). Unlike standard retail chips, the bq40370 is often a "custom" product, meaning TI typically does not provide a public datasheet or technical reference manual. Core Functionality bq40370

2. Key Features

• High-side FET control for charging and discharging paths
• Integrated dual N-channel MOSFET gate drivers
• Overcurrent (OC) and short-circuit (SC) detection with adjustable thresholds
• Overvoltage (OV) and undervoltage (UV) detection with hysteresis and programmable delays
• Pack thermistor (NTC) inputs for temperature-based charge/discharge inhibit
• Status outputs (FLAGS / FAULT) for system MCU monitoring
• Automatic retry and latching fault modes
• Low quiescent current for low-power / standby operation
• Wide supply range compatible with single-cell Li-ion chemistry
• Built-in charge/discharge FETs or gate drive for external FETs (depending on variant)
• Safety certification support and recommended tests for IEC standards

Analysis Software: Professional tools like Battery EEPROM Works and NLBA1 (Laptop Battery Analyzer) are used to clear flags, reset cycle counts, and update Full Charge Capacity (FCC). The bq40370 is a specific battery fuel gauge

Host Devices: It is commonly found in Dell battery models such as the GJKNX and NYFGH. High-side FET control for charging and discharging paths

. It serves as a "gas gauge," monitoring battery health, cell balancing, and protection. NLBA1 Laptop Battery Analyzer and Repair Tool 🔋 Key Functions & Features Fuel Gauging:

Common Applications: Where to Find the BQ40370

If you are troubleshooting a device, finding a bq40370 suggests you are working on high-quality hardware. Common locations include:

• Overvoltage (OV)
• Undervoltage (UV)
• Overcurrent in charge (OCC) / discharge (OCD)
• Short circuit (SCD)
• Overtemperature (OT)