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