Bq40370 〈HIGH-QUALITY ✪〉

High-side N-FET drive (eliminates the need for low-side, improving performance). LED Support

: Unlike standard "IT" (Impedance Track) gauges, the bq40370 uses ACEDV , a hybrid method that provides high accuracy without requiring long "relaxation periods" (idle time) between cycles. bq40370

| Command (hex) | Name | Description | |---------------|---------------|---------------------------------| | 0x02 | Temperature | Pack temperature (0.1°K) | | 0x04 | Voltage | Pack voltage (mV) | | 0x06 | Current | Pack current (mA) | | 0x08 | RemainingCapacity | mAh | | 0x0C | RelativeStateOfCharge | 0–100% | | 0x10 | CycleCount | Number of discharge cycles | | 0x16 | CellVoltage1–4 | Per-cell voltages (mV) | | 0x44 | ManufacturerAccess | Access to data flash, control functions | High-side N-FET drive (eliminates the need for low-side,

+---------------------------------------------+ | BQ40370 | | (32-Pin VQFN Power Management Controller) | +--------------------+------------------------+ | +------------------+------------------+ | | v v +------------------+ +------------------+ | Safety & Protections | Gas Gauging Engine| | - Overvoltage (OVP) | - Impedance Track| | - Undervoltage (UVP) | - Cycle Counting | | - Overcurrent (OCD/OCC) | - FCC Calibration| | - Thermal Cutoff | - Cell Balancing | +------------------+ +------------------+ | | +------------------+------------------+ | v +-------------------------------+ | System Communication SMBus | | (Host Laptop & Firmware) | +-------------------------------+ Key Technical Functions BQ40370 FW V3.14 not calibrate correctly Uses the standard SMBus protocol for talking to

FETs are N-channel MOSFETs, driven with ~10V gate drive (from internal charge pump).

Uses the standard SMBus protocol for talking to the laptop and diagnostic tools.

If one cell group drops significantly lower than the others.