DarinS4Turbo

Just a story on replacing my battery with an aftermarket in case it helps someone later -

I was pretty sure the battery in my 06 was heading for the grave. It cranked slow and the voltage was low (11.9 volts) with engine off even after charging it - and it wouldn't hold a charge for very long according to charger amp reading. I finally had to jump it on a couple occasions. I did peel off the factory battery sticker and check the fluid level in the 6 cells as recommended by an archived post but they were fine.

Since I've heard the dealer charges big $$$ to put in a new one (and this one only lasted 3 yrs anyway) I looked at aftermarket replacements which appear to be the 49 series - e.g. Duralast 49-DL (Autozone) and Everstart MAXX-49 (Walmart). I went with the MAXX-49N for $75.

To preserve power to the car electronics and avoid resets, I just ran jumper cables from my other parked car's battery to the posts under the hood before I started (and was careful to make sure the positive cable in the trunk didn't touch anything metal)

Everything went smoothly - the new battery was the correct length to fit in the factory holder and clamp down (which required a 13mm socket). The factory vent tube plugged right in the battery hole.

After a couple days of driving that definitely solved the problem.

Medic1

Excellent write-up, thanks for the info.

The G Man

I did not know that the battery has a vent tube.

DarinS4Turbo

Yes - at least on mine - battery had a vent hole on each side. 1 hole is plugged, and the other accepts a factory plastic tube which runs out through a hole in the trunk well to keep the acid vapors out of the trunk area I think.

The G Man

So the Everstart MAXX-49 from Walmart has a vent hole already? Was the other car started when you jump the battery for back up power?

DarinS4Turbo

Yes, it has the same type of vent hole as the stock battery. I did not have the other car started (only needed minimal power to keep the electronics/memory alive).

The G Man

Thanks for the tip DarinS4Turbo.

caf

Yeah, thanks for posting your experience. There are many of us whose batteries are 4-5 years old and will probably need replacement soon.

Since my car had been cranking slowly, I did a full charge on my battery charger recently, and it seems better but I'm sure I'll still need a new battery soon.

I scoped out the size 49 battery at Walmart last week and at $75 it's good to know it worked well for you. Much better than the dealer.

chuckee98

For what it's worth, the Bentley manual states that the battery should be replaced with a "cycle-proof" / "leak-proof" or AGM battery - which is good advice. I have had a couple of batteries leak in other cars, resulting in corroded battery trays. If that happens in our Audis, you have a corroded trunk, which is ultimately worse. All my cars, except for the Audi, have Optima batteries in them, which are AGM batteries. Also, the Bentley manual indicates that the Energy Management Control Module must be recoded when the battery is replaced (which is what the dealer is essentially saying, and charging an arm and leg to do). This should be do-able with a Vagcom. Does it make a difference? Don't know. But the Energy Management system is responsible for shutting down non-essential electrical components sequentially when the battery starts draining.

Take it for what it's worth.

The G Man

By connecting another in parallel before replacing the old one, does the Energy Management system still need to be re-program?