How many years did you get out of the original battery??
 

How many years did you get out of your original batteries?? I got 9.5 yrs out of mine. I knew something wasn't right when it was cranking a little slower than normal. So my Dad had a brand new battery laying around that he gave to me and it is a exact replacement. I installed it in there and it cranks a lot faster and my lights are brighter. Plus when i'm in the car playing with my VAGCOM the "Energy Management" message pops up on the screen. The crazy part was, I took a 815 mile road trip down south almost 2 months ago and i'm very fortunate that it didn't fail when I was there. Plus I had a hard time getting the hold down bolt out but I got it out. I would've fought with it somewhere else if it failed.

Here is the pic of the battery and you can tell by the thick dust that it's been in there for a while.

Mine lasted 6 1/2 years; are you sure...
 

Mine lasted 6 1/2 years, from the known history back to when the car was new from paperwork I got.

Thus my question back. Mine was actually changed in the first year. I know from the service history I got from the selling dealer when I bought it CPO, and it was always serviced by that same dealer. Most A8's are now on second or third + owners; I think I remember one on here owned since new (Miter Bally's?). Hence, do you know on yours the battery is actually original? If you look long enough at the case of the old one, you should find the manufacturing date (stamped/burned into the plastic case IIRC on some older Audi OE batteries; the parts counter scratch off month-year type labels are more likely an American style). In turn if original, that batter manufacturing date should be slightly older than the car build date. Car build date (month and calendar year) are shown on a silver sticker on the forward part of the driver's door jamb near the hinges, at least on mine.

if you made it 9 years, that's very good of course.

So yours has been replaced when it was a CPO. I was talking about when it was installed from the factory. Not counting CPO dealer replaced. You did well on yours. What brand battery did you get as a replacement??

If you look at my picture, look at the serial numbers on the battery and by the thick dust on it totally gave it away that I was on the original. Next year at this time when I least expected, it would have for sure failed. So it's a good thing I've changed it.

Mine was first replaced under 4/50 new car warranty
 

Mine was changed in the very first year of its life for some reason. I know from the repair history as I mentioned. The build date on the battery I mentioned in the prior post was later than the car build date; which I saw later when I had the battery out to do trailer hitch/lighting wiring. Thus that first replacement fell under the 4/50 warranty. CPO kicked in for the two years following 4/50. My recent replacement was a month or two ago, and 1 1/2+ years after CPO expired. My A8 is now about 8 years on the road--as a 2006 it was actually built (per the sticker) in the very early part of the model year run in Spring 2005.

The battery in my car from when I bought it CPO was a Varta; common for new car batteries in Audi's too...all the way back to my 73 Audi 100LS with the battery under the back seat. But, the replacement I bought a few months ago when I changed it (in the dealer's parking lot...) also still turned out to be a Varta. It got to where it had to go onto a charger every few days, so I charged it up and just drove there with my 10 and 13 mm sockets and 10mm box end for that little wire that ties to the power mngt. system. I bought the replacement via a dealer parts counter--not much different in net price (dealer parts coupons, etc.) from the local Indy place that has the other battery brands I trust. Doing it there I skipped the install fee and the core deposit step; brought my old VAG COM laptop and put in new (legit) battery #.

Turned out when I did that VAG COM programming, I noticed the prior battery i.d. number didn't even tie to what was in the car, so the dealer must have skipped that step when they did the one year old replacement. BTW, that's another clue of whether a battery is original or not. Not foolproof, but if the i.d./serial number on the battery doesn't tie to the one stored in the power management module, it's a giveaway of a prior battery change.

I have 9 years and it is still going strong (so far).

My 05's original battery lasted for about 5-6 years. My 07 W12 had a replaced battery in it when I bought it last year with 50k miles. That means the original battery in the W12 lasted well under 6 years, to the point in a 6 year period the battery was replaced twice.

My 05 was replaced with a interstate battery, and the W12 I replaced with a battery I got from advance auto parts, turned out to be an OEM battery too.

Wow that's pretty good. You're on the verge of beating me. Does yours look the same as mine??

Wow yours lasted the average life. You would think it would last almost twice the life because of its location and not being around a lot of engine and ambient heat.

The Battery in my W12 lasted 7 years.

Just swapped out the original battery last week. 2004 A8 built in December 2003 so 9 years and 10 months on the original battery. It wasn't dead but it was on it's way out.