Columbus unit code

[notflyingscot]

Just took delivery of 2012 Superb Elegance fitted with this media / sat nav unit. Not clear from manuals if code needed to be input if battery goes flat or is disconnected.
We are often away from home for several months and used to coming home to flat car batteries. Do I need to enter a code and if so where do I find it? If I do get a code from wherever, is that code valid for all time on the particular unit?

[greg32]

You may have a card in your manual with the number. I have found that even after removing the radio and reinstalling it, that the code isn't asked for as it knows the car is still the same