The secondary safety features of the BQ40Z80 can be used to indicate more serious faults via the FUSE pin. This pin can be used to blow an in-line fuse to permanently disable the battery pack from charging or discharging. See the BQ40Z80 Technical Reference Manual (SLUUBT5) for detailed descriptions of each protection function.
The secondary safety features provide protection
against:
- Safety overvoltage permanent
failure
- Safety undervoltage permanent
failure
- Safety overtemperature permanent
failure
- Safety FET overtemperature
permanent failure
- Qmax imbalance permanent
failure
- Impedance imbalance permanent
failure
- Capacity degradation permanent
failure
- Cell balancing permanent
failure
- Fuse failure permanent
failure
- Voltage imbalance at rest
permanent failure
- Voltage imbalance active
permanent failure
- Charge FET permanent failure
- Discharge FET permanent
failure
- AFE register permanent
failure
- AFE communication permanent
failure
- Second level protector permanent
failure
- Instruction flash checksum
permanent failure
- Open cell connection permanent
failure
- Data flash permanent failure
- Open thermistor permanent
failure