A6AvantOwner

Thanks for all the comments so far. Much appreciated. Just to summarise: New battery replaced recently. It's a Varta Dynamic SLI 85Ah (F19). No mention of recoding in the workshop manual, other than keys or radio, but I've never even had to recode any of these and had the car 23 years. Recently replaced alternator with refurbished one. With engine running the multimeter reads about 14 volts, so I guess it's charging OK. Replaced rear cigarette lighter unit as that was draining the battery very quickly, but that seemed to fix the problem. Took daily readings and battery was losing voltage but only a little and after sitting for about 12 days it was over 12v and started. Charged up the battery yesterday and will have a look at it tomorrow (it's raining here). The battery is disconnected so will take a reading tomorrow. I also need to change the drivers window regulator (and check motor) as it stuck halfway up and took a while to get back to closed position. That will have caused a significant drain but not sure if that's the root cause. Will get back to you with my findings in a few days. Thanks for all the comments and advice. Regards ...

Hi Gareth Thanks for the reply. I fully charged the battery and then plugged a multimeter between the car's negative cable and the battery's negative post. The draw was 40 milliamps. I believe that over 50 milliamps may be a problem. I recently went on holiday and the car started ok after nearly two weeks so I thought all was ok. However I went to start the car today and the battery was flat even though I drove it five days ago. It's on a charger now and I'll have to investigate once it's fully charged. Regards Hector

Hi - I have recently replaced my car battery and want to know if I need to code it. It's a 2002 A6 so I don't know if coding is for newer cars/batteries. The battery is also discharging so I think there may be a parasitic draw although multimeter readings were within tolerance. Any help much appreciated. Thanks