Where to Find the Battery in a 2013 Audi A4

In a 2013 Audi A4, the main 12‑volt battery is located in the trunk, on the right-hand (passenger) side, beneath a removable trim panel. This design keeps the battery out of the engine bay, improves weight distribution, and can surprise owners who expect to find it under the hood.

Understanding the Battery Location in the 2013 Audi A4

The 2013 Audi A4, including most B8 and B8.5 generation models (both sedan and Avant), uses a trunk-mounted 12‑volt battery. Instead of sitting near the engine, the battery is placed in the rear cargo area under the side trim. Knowing this location is important for maintenance, jump‑starting, or replacement, and it also explains why you’ll find dedicated jump-start terminals under the hood rather than the physical battery itself.

Exact Battery Position in the Trunk

The battery in a 2013 Audi A4 is mounted in a recessed compartment in the trunk, on the right-hand side. Access requires lifting or removing a section of the trunk floor and then opening or removing the side trim panel that covers the battery bay. This layout is common across many Audi models of that era.

Step-by-Step: How to Access the Battery in the Trunk

The following steps explain how to physically reach the battery in your 2013 Audi A4 without damaging interior trim or wiring.

1. Open the trunk: Unlock the vehicle and raise the trunk lid fully.
2. Clear the cargo area: Remove any luggage, floor mats, or cargo liners that may obstruct access to the floor panel.
3. Lift the trunk floor panel: Grasp the handle or pull tab on the main trunk floor panel and lift it up. In some trims, it may hinge upward; in others, it may lift out completely.
4. Locate the right-side trim panel: Look to the passenger-side wall of the trunk (right side when facing the rear of the car). You’ll see a molded side panel or cover over a recessed area.
5. Remove or open the side cover: Depending on trim, this may be a removable cover, a panel with clips, or a hinged door. Gently pull it away from the body; if clips are present, a careful, even pull will release them.
6. Identify the battery: Inside this compartment, you’ll see the 12‑volt battery, usually secured with a metal or plastic hold-down bracket and connected via positive (red) and negative (black or brown) cables.
7. Check the mounting and cables: Verify that the battery is firmly clamped and that cables are not loose or corroded before doing any work.

By following these steps, you can reliably access the battery compartment without guessing or prying at random trim pieces, minimizing the risk of breaking clips or damaging the vehicle’s interior.

Why the Battery Is Not Under the Hood

Many drivers expect the battery to be in the engine bay, but Audi’s decision to place the battery in the trunk is driven by engineering and packaging considerations. This is standard on most 2013 A4s and is not a sign of a previous repair or modification.

Key Reasons for a Trunk-Mounted Battery

The reasons behind this layout help explain both performance and maintenance characteristics of the 2013 A4.

• Better weight distribution: Moving a heavy component like the battery to the rear helps balance front-heavy, engine-forward designs, improving handling and stability.
• Engine bay packaging: The A4’s engine compartment is crowded with the engine, turbo plumbing, cooling system, and electronics. Relocating the battery frees space for these components.
• Thermal protection: The trunk is cooler than the engine bay, protecting the battery from prolonged high temperatures that can shorten its life.
• Crash safety and design: A rear compartment battery can be packaged more securely in some crash scenarios and simplifies some aspects of front-end design.
• Access to jump terminals: Because the battery is in the trunk, Audi provides designated jump-start points under the hood to keep emergency access simple.

Taken together, these factors show that the trunk-mounted battery is a deliberate engineering choice aimed at performance, durability, and packaging efficiency rather than an unusual or model-specific quirk.

Jump-Starting a 2013 Audi A4: Under-Hood Terminals

Even though the battery is in the trunk, you do not need to expose it just to jump-start the car. Audi provides dedicated jump-start posts in the engine bay, which are the recommended connection points.

Where to Find the Jump-Start Points

The jump-start terminals are placed for quick and safe access under the hood, allowing you or a roadside service to connect booster cables without touching the trunk battery directly.

1. Open the hood: Pull the interior hood-release lever, then release the external latch and raise the hood fully. Secure it with the hood strut if present.
2. Locate the positive terminal: Look near the right side (passenger side) of the engine bay, typically near the firewall or close to the fuse/relay area. You’ll find a covered metal post or a positive terminal clearly marked with a “+” symbol and often protected by a red plastic cap.
3. Locate a solid ground point: Instead of attaching to the battery’s negative post in the trunk, Audi expects you to use a designated ground lug or a robust, unpainted metal part of the engine or body, marked or designed as a ground point.
4. Connect jumper leads in correct order: Attach positive cable to the positive jump terminal on the A4, then to the donor battery’s positive; attach the negative cable to the donor’s negative terminal, then to the A4’s designated ground point.
5. Start the vehicles: Follow the owner’s manual procedure—usually, start the donor car, let it run briefly, then attempt to start the Audi.

Using these under‑hood points avoids the need to remove trunk trim in a roadside situation and reduces the chance of accidental short circuits near the enclosed battery compartment.

Battery Replacement and Coding Considerations

Replacing the battery in a 2013 Audi A4 is not simply a matter of swapping units; modern Audis monitor and manage battery charging through the vehicle’s control modules. Incorrect replacement can lead to charging irregularities or warning messages.

Basic Replacement Steps (Physical Swap)

The following steps describe the mechanical side of battery replacement in the trunk; electronic coding is a separate, important step.

1. Switch off ignition and remove key: Ensure the vehicle is fully off and all accessories are disabled, including interior lights where possible.
2. Access the battery compartment: Use the same procedure described earlier: open the trunk, lift the floor panel, and remove the right-side trim cover.
3. Note specifications and labels: Before disconnecting anything, read and photograph the battery labels (Ah rating, CCA, part number) and any coding stickers; these are often needed for selecting a correct replacement and for coding.
4. Disconnect negative terminal first: Loosen the clamp on the negative (usually brown or black) cable and remove it from the terminal, keeping it away from metal parts.
5. Disconnect positive terminal: Loosen the clamp on the positive (red) terminal and carefully remove it.
6. Remove the hold-down bracket: Undo the bolt(s) or clamp securing the base of the battery, then remove the bracket.
7. Lift out the battery: Carefully remove the battery—note that it is heavy. Use both hands and avoid tilting it excessively.
8. Install the new battery: Place the new battery in the same orientation, reattach and tighten the hold-down bracket, then connect the positive terminal followed by the negative.

Once the physical installation is complete, the new unit will be in place, but without proper coding, the vehicle’s charging system may treat it as the old battery, which can shorten the new battery’s lifespan.

The Importance of Battery Coding on Audi Models

The 2013 Audi A4 typically uses a battery management system that tracks battery condition and adjusts charging behavior. When you install a new battery, the system should be told that a new unit is present—especially if the capacity or type (for example, AGM vs. flooded lead-acid) has changed.

The following points explain why coding matters and how it’s usually done.

• Charging optimization: The car’s control module alters charging profiles based on the battery’s age and health. Without reset/coding, it may undercharge or overcharge the new battery.
• Error prevention: Incorrect or missing coding can lead to electrical system warnings, start‑stop system malfunctions (if equipped), or unpredictable behavior of comfort electronics.
• Diagnostic accuracy: Coding ensures that on-board diagnostics correctly interpret battery voltage, current, and health data for future servicing.
• Use of proper tools: Coding is usually performed with specialized diagnostic equipment such as VCDS (VAG‑COM), ODIS, or compatible aftermarket scan tools capable of accessing the battery management module.
• Professional vs DIY: While skilled owners with the right tools can code the battery themselves, many drivers will prefer a workshop or dealership to handle both replacement and coding.

By combining correct physical installation with proper coding, you ensure that the new battery functions as intended and that Audi’s electrical and charging systems remain reliable over the long term.

Model Variants and Possible Exceptions

For mainstream 2013 Audi A4 sedans and Avants sold in Europe and North America, the 12‑volt battery location in the right-rear trunk compartment is consistent. However, options such as start‑stop systems or different audio packages can slightly alter the surrounding layout—though not the core location.

What Owners Should Double-Check

Because regional equipment and prior repairs can introduce minor differences, it is worth confirming a few details on your specific car.

• Consult the owner’s manual: The manual for your exact VIN and market will confirm the trunk location and show the access panel layout.
• Look for secondary batteries: Some Audi models with advanced start‑stop or high-end audio systems in other ranges can feature auxiliary batteries; if present, they are typically still in the same general rear area.
• Inspect under the hood: If you see only jump terminals and no conventional battery tray, that supports the fact that your main battery is in the trunk.
• Check for non-factory modifications: Previous owners or shops should not normally relocate the battery; if the layout looks improvised, have a technician inspect it.

Verifying these points gives confidence that you’re working with the factory configuration and helps avoid confusion if your car has unusual aftermarket changes.

Summary

On a 2013 Audi A4, the primary 12‑volt battery is located in the trunk on the right-hand side, behind a removable side trim panel beneath the trunk floor. While this may differ from older cars with under‑hood batteries, Audi’s trunk-mounted design improves packaging and weight distribution. For jump-starting, you use dedicated under‑hood terminals, not the trunk battery itself. When replacing the battery, it is essential to follow careful mechanical steps and, ideally, code the new battery into the car’s management system using appropriate diagnostic tools. Together, these practices ensure reliable starting, stable electronics, and long battery life in the 2013 A4.

What size battery is in the 2013 Audi A4?

The 2013 Audi A4 battery size is typically a Group 94R (H7) or Group 49 (H8), but the exact size can vary by trim and original equipment options. It’s recommended to verify the correct size for your specific vehicle using a fitment tool or by checking the existing battery, and it should meet or exceed the original cold cranking amp (CCA) requirements, with AGM (Absorbed Glass Mat) being a common and high-performance option. 
Common battery sizes

• Group 94R (H7): This is a very common size for this model year. 
• Group 49 (H8): Another size that fits, particularly for certain configurations or trims. 

Important considerations

• Verify fitment: The most accurate way to ensure the correct battery is to use an online fitment tool from a parts retailer or check the size on your current battery before purchasing. 
• AGM battery: Many modern Audi models use an AGM battery, which is a high-performance option for a vehicle with many electronic accessories. 
• Cold Cranking Amps (CCA): Ensure the new battery meets or exceeds the original CCA requirements for your vehicle to guarantee reliable starting power. 
• Vehicle reset: After replacing the battery, the vehicle’s computer system may need to be reset. It is best to contact a service specialist for this procedure. 

Is the Audi A4 battery in the trunk?

It. It’s in the back in the trunk just like that. So now you.

How to open a 2013 Audi A4 trunk with a dead battery?

Use your key to unlock the door grab this right here pull these seats. Forward crawl to the back grab this latch here and just push it straight down. You’re good to go.

Where is the battery located on an Audi A4?

The Audi A4 battery is typically located in the trunk, under the spare wheel, in modern models (2009 and newer). Older models may have the battery in the engine bay. For a dead battery, you can jump-start the car using the jump points in the engine bay rather than trying to access the trunk battery. 
Audi A4 (2009 and newer)

• Location: Trunk, underneath the spare wheel. 
• Access: Lift the floor mat, remove the spare wheel, and a plastic cover. The battery is then accessible. 
• Jump-starting: Use the under-hood jump points to avoid needing access to the trunk, especially if the battery is too flat to open the trunk. 
  • Positive (+) terminal: Under a red cover with a “+” symbol in the engine bay, usually near the cowl. 
  • Negative (-) terminal: Connect to an unpainted metal surface on the bodywork in the engine bay. 

This video shows the location of the battery in the trunk and how to access it: 58sTotal TechnikYouTube · Jun 19, 2021
Older models (e.g., 2004-2009)

• Location: Engine bay, under the hood. 

This video shows how to replace the battery which is located in the engine bay: 55sTRQYouTube · Dec 31, 2024