After seven years it is time for a new battery (2011 A4). Before I disconnect it, do I have to apply external power to keep alive the settings?? I used to have to do this in my 2003 A6 (primarily to avoid locking out the radio).

 

Update: I had my indie guy replace the battery and he told me all they had to to after replacing the battery was to "clear the codes". Apparently removal of the battery sets off a number of codes but clearing them with an OBDII reader works.