Hello, Cedric
Unplug detection feature is not available for FM6300. An useful way to know when device is disconnected from main power source and is using battery would be to set External Voltage event in I/O setting when it is very low compared to normal voltage from cars battery for example limit of 9V (By using on exit operand Low/High Values 9000/30000), also you could set up your device to send an SMS after event is generated.
I hope it helps, you are welcome to ask any further questions regarding this situation.
Best regards.
