Tool/software:
Hi,
I'm in the process of configuring the AFE to enable PRECHARGE mode, and for some reason, it is not working as expected. Please see the followings:
Configuration:
- Settings:FET:Precharge Start Voltage = 1mV
- Settings:FET:Precharge Stop Voltage = 3000mV
- Settings:Manufacturing:Mfg Status Init[FET_EN] = 1
- All other registers related to the CHG FET control that could affect the functionality of the PCHG FET are properly configured.
Precondition:
- The BMS is placed between a 15s battery pack and a power supply, which is ready to start charging the battery at 5A as soon as the CHG FET turns on.
- The CHG FET is intentionally kept off by triggering OTC and OTD through a thermistor.
- The minimum cell voltage is measuring 2550mV, which is lower than the Settings:FET:Precharge Stop Voltage.
Procedure:
- Let the AFE recover from OTC and OTD protection by cooling the thermistor, then monitor both the "FET Status() - 0x7F" and the "Battery Status() - 0x12".
Result:
- When the AFE recovers from OTC and OTD, initiating battery charging while the minimum cell voltage is still much lower than the Settings:FET:Precharge Stop Voltage, the AFE directly turns on the CHG FET instead of the PCHG FET. Additionally, the Battery Status()[PCHG_MODE] bit remains clear.
Is there anything that I'm missing in the process of enabling the PRECHARGE mode?
Best regards,
Kyungjae Lee
