TFT

After sitting in the garage for the past 18 days the battery in my 2008 S8 was almost completely dead. It made a weak attempt at cranking and that was it. i have all the invoices from the original owner and the battery had been replaced on 5/25/2010 by Audi so I guess maybe its ready to be replaced. Audi charged him $231 for the battery and $150 for the install. That's an expensive install.
I have searched through a number of threads regarding battery replacement and there is discussion on resetting battery codes. I don't have a VCDS cable ( I have ordered one) so can this be done without the VCDS?
Battery Plus has the battery. Can they install it without screwing things up?

Right now the battery is on a charger.

MP4.2+6.0

You need VCDS to code car for the battery change. Can't be done otherwise.

Do you need to code it in reality? Again, answered many times, at least by me but also some others IIRC. Unknown, but since the system learns the current state of the battery as it deteriorates then unless it only learns in one direction (deteriorating) logically it will learn if things "get better" too. Not documented AFAIK, but that's the logic.

Folks have noted at times performance of the power management system improves (and the battery display) following a recode. Whether it improves longer term anyway hasn't really been nailed down beyond my supposition above.

Mister Bally

Batteries Plus can install the battery "without screwing it up". Some locations have a "difficult vehicle installation specialist". My son happens to be one of those such employees. He floats between two Michigan stores while being a full-time student.

That said, the stores do not code vehicle systems per company policy. The store should advse you up front to make an appointment at a dealer to have coding done. Especially true with BMW's. Then Audi's.

Once you get your genuine VCDS cable from Ross-Tech, you will be able to easily do this. If you ordered a fake from fleabay or Amazon; beware, it won't work.

TFT

I ordered it from Ross tech, should be here Wednesday.
The car will sit for 17 days at a time due to the fact that I go back and forth between Arizona and Alaska. should I put a battery tender on it when its just sitting?

dvs_dave

You can just change the battery without coding it to get you back on the road. It will sort it out by itself, but you may have a few random systems not working fully whilst it figures things out. The recoding of the battery basically resets the power management system which as the battery fails shuts down various non critical systems to save power for cranking.

zedbyers

is the car in alaska or arizona? I too work a rotational schedule (14/14) and do not leave my S8 on a charger while i am away. I do not arm the alarm, and the car sits in a relatively warm garage in florida.

If i am gone more than a month, i do put them on the smart charger.

1Wasserwerks

Oh boo on the dead battery.
You can swap it yourself without coding it right away. It shouldn't be too much of an issue. Since you have VCDS arriving shortly, just pop the battery in so it is mobile.

TFT

The car is in Arizona. I don't arm the alarm either, I have a security system on the house.

SaltyIrishman

Doesn't the car go into "sleep" mode if it is locked and sitting for a certain amount of time? Might be better for the battery to lock the doors when not using the car.

trustzzz

I replace my battery without VCDS, here is how I did it:

1. Jump start the car, replace the battery when car is running.
2. Need to be very careful for the Positive and Negative cable.
3. Don't try is at home unless you know what you are doing.
4. No need the VCDS, even I do have one now.

I did all my car with this way so I don't lose the previous setting.

Again you take you own risk !!