Your RAID configuration is distributed on each of the drives from the array hence the name Redundant Array of Inexpensive Disks. The drives are redundant because the information in its entirety is on each disk.
This allows for either a disk to fail (as long as you have a hot spare and a redundant array) OR the controller to fail.
You would simply change the controller for one of the same model, moving the battery backed cache over too (dont disconnect the battery from the cache module!), and your RAID config would be read off the disks, and the server would boot up fine.
There really is no way nor need to back up the array configuration.