SLUUD63A December 2024 – October 2026 BQ41Z90
STORAGE mode is activated with command 0x000A. When the STORAGE mode command is received, bit 10 (the [STORAGEM] bit) in Operation Status B is set. After Storage Delay time, the CHG and DSG FETs are turned off. However, if after Storage Ignore SMB Delay time the gauge is still not in SLEEP mode, the STORAGEM bit is cleared and the CHG and DSG FETs are turned back on.
The device will exit STORAGE mode when SMBus high is detected.
The gauge needs to be in SLEEP to stay in STORAGE mode, so the Storage Delay time and Storage Ignore SMB Delay time, though not limited, should practically be set higher than the Chg Relax Time and Dsg Relax Time thresholds.
Storage Ignore SMB Delay time can be set smaller than Storage Delay time in test setup with communication disconnected after sending the command, but in practical setup, Storage Ignore SMB Delay time might need to be larger to let the disable FETs turn off communication, so that there can not be any SMBus high to cause the exit from STORAGE mode.