Battery Replacement

[Walker Shippy]

I went to Auto Zone to get my battery tested as my 2012 B8 S4 was being a little sluggish to start up. The guy told me that my battery was fine but I knew better and figured that I had a few weeks before my battery went out. As I predicted, my battery went out completely today and I wasn’t able to start my car. I am looking to replace the battery myself as I hate having other people work in my car but I have a few questions before I can do it. Here are the questions:

I have heard a few things about the ECU needing to be reset after a battery change or else the car won’t start. Is this true?

What battery or type of battery would I need to buy as a replacement if I were to do this myself?

Are there any other things I need to worry about or can I simply replace the battery with relatively no worries?

Thanks a lot guys. :)

[Robdukes]

You dont have to reset the ECU.
As long as your car didnt go into power saving mode..you dont have to do anything.
If it did go into power saving mode, you can put the code from the top of the battery in via coding. Otherwise just change the battery as you would any car.

Sent from my SM-N960U using Tapatalk

[Atrevido]

Recoding the battery is not necessary, but recommended. After replacing my battery I was asked the same question; initially I did not recode
and had no issues at all. Another member informed me recoding helps with battery life, so I did. Took all of 5 minutes.

Others have recommended the Advance Auto Parts "AutoCraft Gold Battery, Group Size H9, 950 CCA". You can use an H8 as well.
I purchased mine online for $123 plus tax for my 2013 S4. Search for an online discount code.

Connect a battery tender to the positive and negative leads to keeps the juices flowing so you don't have to reset radio stations, etc.

[gth141a]

Recoding the battery is not necessary, but recommended. After replacing my battery I was asked the same question; initially I did not recode
and had no issues at all. Another member informed me recoding helps with battery life, so I did. Took all of 5 minutes.

Others have recommended the Advance Auto Parts "AutoCraft Gold Battery, Group Size H9, 950 CCA". You can use an H8 as well.
I purchased mine online for $123 plus tax for my 2013 S4. Search for an online discount code.

Connect a battery tender to the positive and negative leads to keeps the juices flowing so you don't have to reset radio stations, etc.

Do you connect the battery tender to the terminals under the hood or the battery wires in the trunk? Does it matter either way?

[Atrevido]

I connected the tender to the battery cables in the trunk, although it shouldn't make any difference which route you choose.
Just remember to connect the tender before disconnecting the cables from the battery itself.

[RecklessactN]

Recoding the battery is not necessary, but recommended. After replacing my battery I was asked the same question; initially I did not recode
and had no issues at all. Another member informed me recoding helps with battery life, so I did. Took all of 5 minutes.

Others have recommended the Advance Auto Parts "AutoCraft Gold Battery, Group Size H9, 950 CCA". You can use an H8 as well.
I purchased mine online for $123 plus tax for my 2013 S4. Search for an online discount code.

Connect a battery tender to the positive and negative leads to keeps the juices flowing so you don't have to reset radio stations, etc.

My oem battery lasted 10 years! Maybe its a fluke but if you want to do it yourself, replace it with a quality battery and then have an independent shop or dealer do the reset.