I can understand the inconvenience and expense being annoying, but are they necessary?
I'm probably talking out of my backside, so call me appropriate names, but isn't it possible to use cables and crocodile clips to connect each terminals of both batteries and the appropriate cables to maintain constant connection of both batteries to the car's electronics whilst the cables are transferred from the old battery to the new one?
The car will remain blissfully unaware of you changing the battery and so won't demand 're-coding' or whatever it's called!
OK, rather more messing about, but saves an expensive visit to the main dealer.
How I wish I could confirm this either way, but sadly I can't....all I can do is theorise!
Anyway - the story.....
Audi Q7 - a huge vehicle which I think was a V6. The problem was it would only just crank over quick enough to start, - never failed but never inspired confidence. It had been in to a bodyshop for a replacement door and had been repeatedly started with a start/charge pack over that time. Rightly or wrongly I suggested that the battery would have had enough - the car was 7 years old with a low mileage. (60k).
So - along came a spankers Yuasa battery, at great expense and in it went. Before doing anything I connected my Draper memory saver pack into a 12v socket to retain things like the infotainment codes, central locking and so on.
Again, the cranking was slow
so on went my smart charger and 4 hours later it informed me that the battery was fully charged.
The car cranked over just fine - quite a difference
However, after 4 days we were back to the usual slow crank
.
On the battery was marked 'necessary to code' so into Newcastle Audi it went. After that, the car has performed just fine so the only conclusion I can come to was the alternator was 'instructed' by the ECU to charge at a higher voltage than usual
and therefore keeping everything happy!
Who knows....I can't find anyone to talk to who really knows what its all about.
John