VERIFIED SOLUTION i

Designer - How to perform a Repository Backups from command line

Product Feature: Backup
The following can be used for a trusted Connection (the green value is the server name, the blue value is Designer Repository Name):
sqlcmd -E -S localhost -d Doc1_Repository -Q "Exec dbo.spBR_FullBackup"

or for a SQL authentication use (the red value is SQL username, the orange value is SQL password,the green value is the server name, the blue value is Designer Repository Name):

sqlcmd -U sa -P sa -S localhost -d Doc1_Repository -Q "Exec dbo.spBR_FullBackup"

This will create the backups in the Location set in the repository.
The repository backup location can be found by looking in the dbo.Global table for the repository that is being backed up. If necessary the BackupRoot and ZipRoot can be changed to a more suitable location.
UPDATED:  April 3, 2017