DSGW-040 LTE Gateway with Battery, How To Detect if Power is removed

I’m using a variation of DSGW-040 4G LTE IoT Router Gateway and I would like to know how to detect when it is unplugged from power and it is operating using internal battery.

I do capture the SysLogs, but I couldn’t find any information from the logs when the power is cut and the gateway is operating using its internal batteries.

Does anyone know if there is a way to write a script or configure the gateway to send the information to a server or remote logs related to input power or internal battery status.

Thank you