so all of a sudden my car died one morning and i had to jump start it. It worked all day...stayed in garage for 7 hrs and started again but after i left it overnight, it stopped working again in the morning. So jump started again....i am getting battery check done but do you guys think it's an alternator or I just need a new battery. Can it be something else?

Also, should i get after market battery for my 06 A6?

Thanks

 

power probe is a great tool for u to check electrical much safer on cars with electronics like audis as u dont need to worry about blowing circuts . maybe something is pulling power as well. check battery first then alt.

 

go to autozone or someone for a battery that can do a simple load test, that will check battery condition as well as alternator output.

 

when my alternator started to go, it was intermittent. most of the time it would be fine but slowly, over time it would get real "flaky" with voltage output. as stated above, most autoparts stores can load test the battery and check your charging system. the problem is if your alternator is going "slowly" as mine did, their test may not catch the problem.

based on your description of what is going on with your car, my initial thought is a battery issue. an easy (but not foolproof) way to monitor what is going on with your electrical system is to keep an eye on your voltmeter. When you turn on your ignition it should go to just above 12 V. Don't start the car right away, keep an eye on the volts. it should pretty much hold right where it is. If it starts to drop off right away, or drops rapidly, it's probably the battery. when you turn the car over it should drop to about 10. when the car is running is should go up to between 14 and 15 and stay there. if it fluctuates while your car is running it is probably your alternator.

good luck

 

I am taking it to NTB...hopefully they can diagnoze but can't find anyone to jump start...I need one of those battery jumpstarters.

Thanks for the reply

 

So NTB says everything is ok but for some reason i have water seeping into my trunk, where the tire and battery is and because of that it's causing battery to drain or something. Does that make sense? I called Audi and they said that since its been 4 yrs. i should replace the battery. So on one hand NTB is saying battery, alternator and start test came out clean and everything is ok. On the other hand, it does make sense that I should replace the battery since its been 4 yrs. IDEAS??

 

I would say its the battery, mine died last month. Took it to autozone and they confirmed that in fact it was dead (not just drained from power). Today I did my timing belt job and decided to take my alternator out while I was in there and check the brushes. They were very low so I replaced the alternator too How many miles are on your car? An alternator should last you 100k+ easy, but there have been cases of them failing at 60k too. If your volt meter is at around 14-15V then you should be fine. BTW, my battery died and it was only 3 years old.

 

I have 71k miles on my car and whatever test NTB did, they found no issue with battery or alternator. They even gave me test results that says everything is ok and blamed it on some water thats next to batt.

I really hope its just the batt and nothing else. I think this is the original battery...i never replaced it in last 4 yrs (since i bought this pre owned car)

 

If Battery AND Alternator checked out, the it sounds like something is draining the Battery after you shut the car off.

I would say leave the battery unplugged overnight and see what happens the next morning, but I don't know how that affects the C6 A6 (radio, windows, ecu, immobilizer, throttle adaptation etc).

 

Well after I dried up the water next to the battery yesterday, it turned on this morning without having to jump start. I am not sure if this was a fluke or if water has anything to do with the battery but i didnt have to jump start. Call it coincidence but not sure why it started up. Only thing that changed since yesterday was that i dried up all the water inside next to the battery. Can this be it? I am confused for sure.