SLUUD50 October 2024 BQ27Z758
This command enables/disables control of the CHG and DSG FETs by the firmware. The initial setting is loaded from Mfg Status Init[FET_EN]. If the ManufacturingStatus()[FET_EN] = 0, sending this command allows the FW to control the CHG and DSG FETs and the ManufacturingStatus()[FET_EN] = 1 and vice versa.
In UNSEALED mode, the ManufacturingStatus()[FET_EN] status is copied to Mfg Status Init[FET_EN] when the command is received by the gauge. The device remains on its FET control state through resets.
The firmware FET control state can only be changed while the gauge is in the UNSEALED mode. FETs are closed only if there are no safety violations. When ManufacturingStatus()[FET_EN] = 0, the FETs are open and no current flows in or out of the cell.