Q: My iPad won't backup to iCloud when plugged in

Hello, Bigbucks2780. 

Thank you for using Apple Support Communities.

I would need a little more information regarding any error messages received or behavior to better assist you.  However, I would take a look at these articles as they provide some helpful troubleshooting steps for the iCloud backup issue you are experiencing.

iCloud: Troubleshooting creating an iCloud backup

http://support.apple.com/kb/TS3992

iCloud: Understanding Backup alert messages

http://support.apple.com/kb/TS4576

Cheers,

Jason H.