SLUUD50 October 2024 BQ27Z758
The device provides overtemperature and undertemperature protections based on cell temperature measurement. The cell temperature-based protections are further divided into CHARGE and DISCHARGE conditions. This section describes in detail each of the protection functions.
The device supports up to two external thermistors and one internal temperature sensor for measuring temperature. Unused temperature sensors must be disabled by clearing the corresponding flag in Settings:Temperature Enable[TS2][TS1][TSInt].
The Temperature() command returns the cell temperature measurement, which is the maximum of the enabled temperature sensors.
AltManufacturerBlockAccess() command DAStatus2() returns all the temperature measurements.
The cell-based overtemperature and undertemperature safety provide protections in CHARGE and DISCHARGE conditions. The battery pack is in CHARGE mode when BatteryStatus()[DSG] = 0, where Current() > Chg Current Threshold. The overtemperature and undertemperature in charging protections are active in this mode. The BatteryStatus()[DSG] is set to 1 in a NON-CHARGE mode condition, which includes RELAX and DISCHARGE modes. The overtemperature and undertemperature in discharge protections are active in these two modes. See Section 8.6 for detailed descriptions of the gas gauge modes.