The SA380TX-L does not have internal battery backup. Removing power will cause the logger to shut down.
To safely power down the logger, the following procedures should take place:
Mains:
Turn the plug off by the switch and remove the plug from the socket.
Press the clip on the logger power connector and pull the connector out of the logger.
Busbar:
Disconnect the fuse that connects the logger to the busbar.
Press the clip on the logger power connector and pull the connector out of the logger.