SLUUCA6 October 2021 BQ27Z746
Resistance updates take place only in DISCHARGE mode, while OCV and QMax updates only take place in RELAX mode. Fast QMax will update at the end of discharge (see Section 8.7.2 for details). Entry and exit of each mode is controlled by data flash parameters in the subclass Gas Gauging: Current Thresholds section. When the device is determined to be in RELAX mode and OCV is taken, the GaugingStatus()[REST] flag is set. In RELAX mode or DISCHARGE mode, BatteryStatus()[DSG] is set. Figure 8-1 shows the flow.
CHARGE mode is exited and RELAX mode is entered when Current goes below Quit Current for a period of Chg Relax Time. DISCHARGE mode is entered when Current goes below (–)Dsg Current Threshold. DISCHARGE mode is exited and RELAX mode is entered when Current goes above (–)Quit Current threshold for a period of Dsg Relax Time. CHARGE mode is entered when Current goes above Chg Current Threshold. Figure 8-2 shows an example of the operating modes.
The configuration options for the gas gauge modes are in the following data flash.
Class | Subclass | Name | Type | Min | Max | Default | Unit | Description |
---|---|---|---|---|---|---|---|---|
Gas Gauging | Current Thresholds | Dsg Current Threshold | I2 | –32768 | 32767 | 60 | mA | DISCHARGE mode Current() threshold |
Gas Gauging | Current Thresholds | Chg Current Threshold | I2 | –32768 | 32767 | 75 | mA | CHARGE mode Current() threshold |
Gas Gauging | Current Thresholds | Quit Current | I2 | 0 | 32767 | 40 | mA | |Current()| threshold to enter RELAX mode |
Gas Gauging | Current Thresholds | Dsg Relax Time | U1 | 0 | 255 | 60 | s | DISCHARGE to RELAX timeout |
Gas Gauging | Current Thresholds | Chg Relax Time | U1 | 0 | 255 | 60 | s | CHARGE to RELAX timeout |