Where is the Audi A4 Battery?

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Trey is an automotive enthusiast and has a huge passion for Volkswagen and Audi vehicles of all kinds. His enthusiasm started with the MK5 GTI, and he has massively expanded his knowledge over the years. When Trey is not delivering high-quality and in-depth content, we can usually find him working in his garage on his modified Genesis coupe. Trey created VW Tuning several years ago, and he is the primary visionary behind the content.
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This is a common question because on many German cars, batteries are not necessarily under the hood. So, have you ever looked and wondered “Where is the Audi A4 Battery Location?” Now, there are 5 different Audi generations, so we will be focusing specifically on the B8 A4 for this post. However, if you happen to have any other A4’s, B5 A4, B6 A4, B7 A4, or B9 A4, we will list where the batteries are found near the bottom of this post. So again, we will be going over where the Audi A4 B8 battery is located, how to remove it, and how to install and recode it.
Where is the Audi A4 Battery Located?

Before jumping into the removal of the battery, we highly suggest putting on a pair of gloves for this DIY.
First thing, look in your car manual to identify where the car battery is located. Oddly enough, the battery on most A4 B8’s are located under the spare tire compartment, pictured above. “How do I get to that though?” Well, if you open the trunk, pull the floor panel, twist on the wingnut that is securing the spare tire, and pull out the spare tire. Once the spare tire is removed, there should be a tool tray underneath, remove that. Now you should see what’s pictured above. As you can see, there are brackets holding the battery in place. There are 4 13mm bolts securing the brackets, once these are removed the battery should be freed.

Once the battery has been removed, your trunk should look like the above picture. Now it is time to install and code the new battery. Here is a battery that we recommend using, but feel free to get whatever battery you would like, as long as it fits the Audi A4 B8. Plop the new battery into the same position as the old one and make sure the terminals are free of corrosion. Once corrosion-free, plug the vacuum hose, or vent tube, reconnect the positive cable, and lastly connect the negative cable. Replace the tool tray and spare tire. You will be able to turn on your vehicle, however, it will be running in low power mode because it won’t be coded for the new battery.
How to Code an Audi A4 Battery
In order to recode your new Audi A4 battery, you will need access to VCDS software. First, if you have no idea what I’m talking about, it may be best to take the vehicle to a dealership for them to code it so nothing goes wrong. You will need a scan tool to be able to recode the battery. Here is a video that will better explain how to replace and recode the Audi A4 battery.
Common Audi A4 Battery Locations
In this section, we will list the battery locations we’ve seen for all of the A4’s. Unfortunately, not all A4 batteries will be in the same place, so hopefully, this assists you in finding it. We want to say it one more time, make sure to check your vehicle’s manual as it will tell you where the location is. However, we know sometimes that the manual is not accessible or didn’t come with the used A4 you bought.
Audi B5 A4 Battery Locations
- Engine bay firewall
Audi B6 A4 Battery Locations
- Engine bay firewall
Audi B7 A4 Battery Locations
- Engine bay firewall
Audi B8 A4 Battery Locations
- Under the spare tire in the trunk
- Engine bay firewall
Audi B9 A4 Battery Locations
- Under the spare tire in the trunk
Now you may be asking, what does the “Engine bay firewall” even mean. See the pictures below to understand what we are referencing. Most batteries in the engine bay should be covered, but we have seen some that aren’t.
Audi A4 B7 TDI Battery Location

Audi A4 Battery – Firewall

Audi A4 Battery Conclusion
To conclude this post, we want to reiterate one more time, your manual should tell you the location of your A4’s battery. Most A4’s, B5 – B7 will be found under the engine bay, while most B8 – B9 A4’s will be found in the trunk or boot of the vehicle. A mechanic or local dealership will likely charge around $600 to replace and recode the battery for your A4. We hope this quick guide helps you locate and replace your A4 battery. Let us know your experience in the comments.
Also, if you would like to read more Audi content, here is our write-up on “Audi quattro®: What Does it Mean?”