CMD: (bitsadmin is depricated)
bitsadmin /transfer <DownloadJobName> /download /priority normal http://example.com/example.txt C:\example.txt
BITSAdmin tool does not provide an option to ignore certificate errors
PS:
Invoke-WebRequest -Uri http://example.com/example.txt -OutFile C:\example.txt
Start-BitsTransfer -Source http://example.com/example.txt -Destination C:\example.txt
Invoke-WebRequest -Uri https://example.com/example.txt -OutFile C:\example.txt -SkipCertificateCheck
(to skip certificate errors)