dark current on A6 [Archive] - Audi Forums

: dark current on A6


scrapman
01-13-2010, 07:14 AM
I have a 2005 A6 and just had the 5 year old battery replaced by the dealer. I checked the charging system at 13.74 volts so it is working. Problem is that the battery barely gets to 12.2 volts. I suspect dark current or something remaining on as a constant drain. I want to check but if i disconnect the battery the way i need to, will I lose settings that I'll need to take it back to the dealer for reset? if so, is there a way around it?

dadwalker
01-13-2010, 07:04 PM
Dark Current??

Thats heavy physics stuff. Something to do with gaseous-discharge devices and photoelectric cells or tubes or something?(googled it, lol)

I had a new battery a few weeks ago. if the car stands for 4-5 days it gets real low still. But remember if you take a V reading while connected it won't be acurate due to the car(basic systems etc) pulling it down.

To take the battery off I used a lead acid 12Ah to keep the settings. Off and on was fine but I understand you can connect to the connections under the bonnet, drivers side. However, I used VCDS to perform basic settings once the new battery was fitted.

And good luck with that dark matter!

singhl
01-17-2010, 09:38 AM
If you have MMI and sat nave then see http://www.fileden.com/files/2007/3/13/883667/audi.tb.91-07-13.pdf

There is a problem with early MMI not turining radio off (even though screen is off), the radio stays on a drains battery.

You will have to update the MMI software to latest version to stop this.

There is no problem with the battery, the car is draining it whilst parked.

a8 tech
01-17-2010, 10:13 AM
If you have a 5f use the battery manager information and carry out a drain test only after shutting all the networks down.

All vehicles
ignition off all doors locked but open for access, bonnet open with the lock engaged
Leave the battery connected for a drain test and connect a ammeter to the negative lead and take a reading after 2 hours, this should be 0.050 amps or lower

To highlight any drain for 5f vehicles firstly run a diagnostic and highlight any possible issues then read off the battery manager history for time date and consumer which stayed on then use a cfd to disconnect the consumer circuit until the drain source is established