This it the second time for the same problem.

Situation:

The first time I had left the radar detector on and a few days later the battery was dead. I jump started the car with my home charger and left for a 200 mile trip. It just so happened that I was having the second service done at the dealer that day. I mentioned the problem and the fact that the battery meter still showed only 10% charge even after a trip of two hours on the highway. They did a quick scan and checked the battery but found nothing wrong.

The second time it happened, today, I was recharging my phone battery and listening to some music on my car-iPod. The charger only took 30 minutes but I decided to look at the battery meter and it showed 60%. I was surprised as I did not think the power draw would be that high. I drove the car to another location and parked it. Just for fun I checked the battery meter and it showed now 20%. This with having done nothing but drive the car. It was only about 1/2 hour later. I then tried to start the car but it just clicked and would not turn over. Called Roadside Assistance and they jumped the car's battery. It started immediately. From then on I left the car running until I came home, some 6 hours later and of which 2 hours was highway driving. Checked the battery meter and it still showed 10%. I tried to start the car I it started without any problems.

I am charging the battery now with my battery charger. It is now, after about 3 hours, at 60%.

Here is a print our of my Vag-Com test.

Any suggestions as to the problem?

<img src="http://pictureposter.audiworld.com/10170/file_1.jpg">
<img src="http://pictureposter.audiworld.com/10170/file_2.jpg">
<img src="http://pictureposter.audiworld.com/10170/file_3.jpg">
<img src="http://pictureposter.audiworld.com/10170/file_4.jpg">
<img src="http://pictureposter.audiworld.com/10170/file_5.jpg">
<img src="http://pictureposter.audiworld.com/10170/file_6.jpg">
<img src="http://pictureposter.audiworld.com/10170/file_7.jpg">
<img src="http://pictureposter.audiworld.com/10170/file_8.jpg">
<img src="http://pictureposter.audiworld.com/10170/file_9.jpg">

Thanks for any suggestions.

 

Connect positive then negative and remove negative then positive?

 

But your question does not address why it happened in the first place.

Recharging the battery by myself actually corrected the problem.

 

An internal short will cause exactly what you describe, slow to charge, won't hold charge. Happened to my wife's A6.

 

but you have to change it once it's dead.

I normally have them charge it every service.

 

battery went to 30% and gave me a warning to turn on the car or system will shut off. Turned on the car for 30 mins and battery was back to 100%...

i think you should have the alternator checked out as it should put out somewhere past 14V to charge the system -- it may be putting less than 12V which causes the system to drain the battery...

 

A deep cycled automotive lead acid battery usually needs to be replaced as it will no longer hold a charge efficiently.

Sounds as if its time to replace the battery.<ul><li><a href="http://www.howstuffworks.com/question219.htm">Deep cycle battery...</a></li></ul>

 

His feeling is that it is not the battery because it hold a charge once recharged by an external source. He feels it may be the alternator which is not supplying enough current to meet the needs of the car and also recharge the battery when an unusual load it place on it.

In my case just sitting and listening to music may have been the 'straw that broke the camel's back' causing a low current in the battery which was not recharged by the alternator.

I have an appointment on Sept. 18 and will see if they are able to fix it then. They will probably replace the alternator and check the battery.

 

Batteries are still lead acid, if one cell is dry it's a dead giveaway that the battery has had it

 

You can't open them either to top up the fluid.

Quite a rip-off. I kept conventional lead acid type alive for 4-5 years by maintaining it properly.