I have a 2005 A6 and just had the 5 year old battery replaced by the dealer. I checked the charging system at 13.74 volts so it is working. Problem is that the battery barely gets to 12.2 volts. I suspect dark current or something remaining on as a constant drain. I want to check but if i disconnect the battery the way i need to, will I lose settings that I'll need to take it back to the dealer for reset? if so, is there a way around it?