I got my 2007 A3 2.0 TDI on August 2012. Due to several reasons, it has spent most time since them unused. Well, that lead to a couple battery discharges which I thought were due to not using the car... Then, when I have tried to use the car, I have found that perhaps the problem was not just the car sitting for too much time but that there is an excessive battery drain when car is parked.
Thinking that the old battery was bad, I got a new one this week. I measured 12.60V on it as it came from the store, so I put it on my battery charger overnight. It is a good one, a CTEK MXS 5.0. Next day, battery was charged and I put it on the A3. Battery voltage, once connected, was about 12.8V. So far, so good.
But then, next day, I found that battery voltage was down to 12.63V. Yes, still seemed like it hold a decent charge, but I wondered if the car was draining too much when parked. Of course, all interior lights were off and there were no accessories connected. So I put the Fluke 77 III meter in DCA mode and measured the drain. It started after the battery connection at about 1.5A. Then it fastly dropped to 1.0A and then to 0.5A or so. And, finally, in a minute or so, it went to 0.17A (170mA). And it sits there, at least for 15 minutes or so (I have left the meter measuring and will check later, just in case it goes to some kind of sleep mode)
But, supossing it keeps draining 170mA, I think it is by far too much, as that would mean a 4.08A/h discharge in a day and 28.56A/h in a week. As battery is a 70A/h unit, that would mean a dead battery in about 2 weeks!
So, please, does someone know which should be the current drain on a car like mine?. If mine is too high, which would be the primary suspects?. Would you use the trick of removing fuses to find it?
Thanks for your help and best regards,