Good morning all,

 

I am new to this forum so please be patient with me. I have purchased an S3 as a project car I have put most things right so far. One question I am trying to get to the bottom of is do I need to have the new battery I have installed coded??

The car has a parasitic draw which has been majorly reduced by the removal of the aftermarket stereo. However the battery (new, just purchased, is still going flat within a week. Alternator good and tested. Problem with alarm horn (which is probably another drain as this seems to be a common problem) but the fact that I installed the battery myself without coding, could this be contributing to the draw?? 🤔

Any advice or information will be very appreciated. 

My A3 2007 needed coding so I assume yours does as well. However I would expect a lack of coding to over charge the new battery not under charge it, so it's likely you still have a drain.

Hi, thanks for your response it is much appreciated. I definitely still have a drain 😂 amongst other things.  However I did wonder if the lack of coding was adding to the issue as the battery that came in the car when I bought it was way too underpowered. 

2 minutes ago, Drucifer said:

 However I did wonder if the lack of coding was adding to the issue as the battery that came in the car when I bought it was way too underpowered. 

Quite possibly. If the car had adjusted itself to charge a low capacity battery then it seems to me that it will not charge a high capacity battery adequately. That's a bit speculative so I suggest you get some certainty at a dealer (Audi or independant) that can advise and code.

Hi Cliff, much appreciated and thanks for the advice. 👍

Please let us know the outcome.

My battery has now been coded to the car. Reading the voltage, it’s definitely charging at higher rate on the battery. I will test over the next week and update. 

That's good to read Andrew. Please spread the word about the need for coding. Good luck in finding the power drain.

Many thanks @cliffcoggin. Will do. 👍

Hi @cliffcoggin. Hope you are well, I thought you maybe interested to hear that I finally found my power drain. It turns out it was the voice control module under my driver seat that was causing the draw. Despite disconnecting the stereo and isolating the amplifier. The draw was still active and causing enough drain to send the battery flat within two days. After finding a good auto electrician this has now been isolated and the cars battery is holding a full charge. The auto electrician sorted this in a few hours and £70.00 well spent. 😁I will be looking at getting this repaired once I install a new stereo as getting to the wiring involves taking the carpets up.

Thanks for letting us know.