(April 22, 2015 at 10:01 pm)AFTT47 Wrote: SteelCurtain, I have a background in electronics. I can tell you that car batteries are specifically designed to produce a large amount of amperage at once for starting but they will be damaged if they are too deeply discharged too many times. It wouldn't take much to damage it (especially in a hot climate). Modern cars have so many systems, it might be difficult to detect where the draw is coming from. You would have to use an ammeter to measure the draw on the battery when the car is sitting while disconnecting various systems and see when the drain goes away. The simplest way to do that would be to sequentially remove fuses and observe the change in current draw. It could also be a case of inadequate charge from the alternator. A faulty charging system could cause that or it could be something as simple as a slipping belt.
I'm not familiar with Audi but I can vouch for Subaru. They have a unique design ethic. Good, reliable cars. If you want something sexy, get a Tesla.
The first thing that entered my mind when reading the description was the alternator/charging system, too. Your idea of making sure the belts are not slipping, as well as your other advice about checking what is drawing power from the battery when it is sitting (if there is too much being drawn while sitting), are good suggestions.
"A wise man ... proportions his belief to the evidence."
— David Hume, An Enquiry Concerning Human Understanding, Section X, Part I.
