Does 2011 A3 need battery coding?

[31satara]

Hopefully a short one. A freind has a 2011 2l petrol A3. In Febuary his battery (original) was completely flat and he bought a new Bosch S4 (74Ah) which I fitted for him. Yesterday it wouldn't start or turn over. When I went to look today the battery was completly flat, 4V off-load. Being retired he doesn't use the car much - maybe once a week a few miles to the shops and back. Normally I would suspect that he's just not using it enough, but it seemed odd that the battery was so flat (unless he has left things on, but he says not). He then said he had been looking on the internet and some cars need new batteries coding - can anyone tell me if this model does need replacement battery coding? Thanks.

[31satara]

I don't think it is the 2l, rather the 1.8tfsi

[philipharmes]

It's usually only cars fitted with stop/start systems ( and therefore AGM or EFB batteries ) that need coding.

[Fexo]

Yes, I fitted an S4 to my wife's old A4 Avant and no coding was needed. When the battery on my A3 with stop/start had to be replaced, that did need coding.

Hold on: my car is a late 2011 A3 2 litre TDI and has stop/start. Are you sure about the battery? The garage was going to fit a standard S4 on mine until they realised it had stop/start which requires a much more powerful (and expensive) one.

[31satara]

Thanks for the info. It doesn't have stop/start nor the multi-media display which seem to be pointers towards coding required. However, the owners manual that came with it states coding is needed when replacing the battery. I connected it to VCDS and was able to go through the coding proceedure without issue. Hopefully that will improve it a bit, but I'm still not convinced it will make much difference - I think he just needs to use it more (it's only got 35k on the clock). There must be loads of similar cars that have had replacement batteries fitted without being recoded.

[Texmilb]

I have a 2011 2.0 TDI with stop/start and when my battery died 4 years ago I just fitted a replacement from Halfords and has been no problem ever since.