CarOwner2020

Hi All,

Audi A8 D3 2005, the battery goes flat after opening any doors and closing a few times which results in having to charge it. I have VCDS and tried to plug in but battery level instantly drops to barely anything resulting in the vehicle having to be started, I have OBDEleven which doesn't make the vehicle go flat but kinda odd when everything is powered off and the vehicle goes to sleep, as soon as you wake it up i.e. open the door, it drains.

Just curious if anyone has any suggestions regarding this?

fjord

I would get your battery tested first. Autozone/Advance Auto will come out to your car, hook up a battery tester and print a report for you.

CarOwner2020

Lets presume the battery was good, is there any other suggestions as to what could possibly be the issue to this?

fjord

You can start your car and then use VCDS to do a complete scan. From what you are describing I am lead to believe you have a large parasitic draw on one of the components that wake up when the car is opened. What I would do next is pull the fuses one by one and see if any of them prevent this large current draw.

MP4.2+6.0

When battery is going bad, other electronics flare up at times and erratically and then it all sort of crashes down. Thus on mine w/ low battery, it would start turning on inside LED lighting and not want to give up/let it turn off. Last battery crash on mine was quick--witthin a month it went from one flat situation after some days sitting, to where you could have it on a charger for a day, start and drive to the corner store, and then it was dead again by very next start in 30 minutes.

As stated, get it started and then run VCDS that way if necessary.

On a 2005, you should be on about the third battery by now, so that remains the low hanging fruit. If not known to be replaced in last 4 years or so, much more likely.

awdinut

And spend the extra $ it takes to upgrade to an AGM battery.