If it was me and I wanted to have a backup copy of all my Profiles and Favorites Lists, here is what I would do.
Start Sentinel. Go to Tools>Options and make a note of the location of the Sentinel Folder. Then I'd close Sentinel and get into Windows Explorer, navigating to that Sentinel Folder location. I'd copy all of the contents to a thumbdrive.
I prefer this option because duplicating the programming to a second SD card only gets the active Profile and those Favorites Lists downloaded to the scanner. Any other Profiles or Favorites Lists that you have created, but are not "active" won't be written.
That was before I got real paranoid about losing files. Now I'm doing external drive backups on a scheduled basis as well as Carbonite.