What Size Battery Is in the 2008 Audi A6?

The 2008 Audi A6 typically uses a Group 49 (H8) or Group 94R (H7) 12‑volt AGM or lead-acid battery, with a capacity around 80–95 Ah and a cold-cranking amps (CCA) rating generally in the 720–850 CCA range, depending on engine and market. This article explains how those sizes vary by configuration and what you should look for when replacing the battery.

Understanding the 2008 Audi A6 Battery Specification

Audi configured the 2008 A6 with different engines and equipment packages, which slightly change the recommended battery capacity and sometimes the exact size code. However, most North American and European models fall into the H7 (94R) or H8 (49) group, both of which are large European-style batteries designed for higher electrical loads and cold-weather starting.

Common Battery Group Sizes for the 2008 Audi A6

The 2008 A6 uses European “DIN/EN” style batteries that in North America are usually cross-referenced to BCI (Battery Council International) group sizes. The following list outlines the most commonly specified groups and what they mean for owners.

• BCI Group 94R (H7): Common on many 2008 A6 3.2 and some 2.0 TFSI models; length ~12.4 in (315 mm), width ~6.9 in (175 mm), height ~7.5 in (190 mm); reversed terminals (“R”).
• BCI Group 49 (H8): Often used on higher-load configurations, some 3.2 and 4.2 V8 models; length ~13.9 in (354 mm), width ~6.9 in (175 mm), height ~7.5 in (190 mm).
• DIN/EN equivalents: Typically labeled around 80–95 Ah on the OEM battery, with CCA ratings in the 720–850 CCA range depending on brand and exact spec.
• AGM vs. flooded lead-acid: Many replacement guides now recommend AGM (Absorbent Glass Mat) batteries for better durability and support of higher electrical loads, even where the original may have been conventional flooded lead-acid.

These group sizes are physically compatible with the A6’s battery tray and hold-down system and provide the necessary electrical capacity and cranking power for the car’s V6 and V8 engines and relatively complex electronics.

Engine and Trim Variations

The precise recommended battery spec can vary by powertrain, equipment level, and region, but the main differences are usually capacity (Ah) rather than physical size. The next list breaks down the typical configurations seen in the 2008 Audi A6 range.

• 2.0 TFSI (where offered in 2008): Often fitted with a Group 94R (H7) battery, ~80 Ah, ~720–800 CCA.
• 3.2 FSI V6: Commonly specified with Group 94R (H7) or Group 49 (H8), usually in the 80–95 Ah range; many catalogs in North America list H7 as the default replacement.
• 4.2 V8 (S-line, higher-spec models): Frequently listed with Group 49 (H8), often toward the higher end of the capacity range (90–95 Ah, 800–850 CCA) to handle greater starting load and more electrical equipment.
• Quattro vs. front-wheel drive: Drivetrain type itself does not usually change the physical battery group, but high-option quattro models often ship with higher-capacity batteries within the same group size.

While engine and trim differences may adjust the capacity and CCA recommendations, the physical dimensions remain within the H7/H8 family, so replacements usually fall safely into one of these two BCI group categories.

Key Battery Ratings for the 2008 Audi A6

Beyond physical size, several technical ratings determine whether a battery is truly suitable for a 2008 A6. These numbers matter for reliable cold starts, stable electrical behavior, and compatibility with the charging system.

Voltage, Capacity, and CCA

The following points outline what to look for in a replacement battery to match the original Audi specification as closely as possible.

• Voltage: 12 V nominal (standard for passenger vehicles).
• Capacity (Ah): Typically 80–95 Ah is recommended; going slightly higher in Ah within the same size is generally acceptable and can be beneficial for short-trip or high-accessory use.
• Cold-Cranking Amps (CCA): Usually in the 720–850 CCA range; match or exceed the original spec, especially in cold climates.
• Reserve Capacity (RC): Higher RC is beneficial for an A6 due to its extensive electrical equipment (lighting, climate control, infotainment); many H7/H8 batteries will offer robust RC suitable for this platform.
• Terminal layout: The “R” in 94R indicates reversed terminals; ensure the positive and negative posts match the original orientation to avoid cable reach or polarity issues.

Matching these technical ratings ensures the A6’s engine management, comfort systems, and safety electronics operate reliably and reduces the risk of hard starting or repeated battery failures.

AGM vs. Conventional Lead-Acid in the A6

While not every 2008 A6 left the factory with an AGM battery, many modern parts catalogs recommend AGM replacements due to the model’s electrical demands. The list below highlights the trade-offs.

• AGM (Absorbent Glass Mat): Better vibration resistance, lower self-discharge, improved performance in cold weather, and more tolerant of frequent short trips and high accessory load.
• Conventional flooded lead-acid: Usually cheaper; still acceptable if it meets size, CCA, and Ah requirements, but may have shorter lifespan in heavy-use or high-load conditions.
• Charging system compatibility: The A6’s alternator and voltage regulation are generally compatible with AGM; no hardware changes are normally required.
• Longevity: AGM batteries typically offer a longer service life under the kind of usage patterns common to luxury sedans (urban driving, lots of accessories).

Choosing an AGM battery that matches the original capacity and size is often the best long-term solution for owners who intend to keep the car for several years.

Location, Replacement, and Coding Considerations

Battery size is only part of the story: access, mounting, and the car’s electronics also influence how a battery change should be handled on a 2008 Audi A6.

Battery Location and Fitment

The A6 (C6 generation, including 2008) typically houses its main battery in the trunk, under the floor panel on the right-hand side in most markets. The list below explains why this matters when selecting the size.

• Trunk-mounted design: Allows for a physically larger battery (H7/H8) and better weight distribution.
• Battery tray size: Designed to accept H7 and H8 types; check that the replacement battery’s length and width sit correctly in the tray.
• Hold-down points: Ensure the battery has compatible flanges or lips at the base so the factory clamp can secure it properly.
• Cable reach: Using the correct group size avoids strain on cables and ensures proper terminal coverage and insulation.

Confirming that the new battery matches the original physical form factor prevents fitting issues and helps maintain safety in the event of an impact.

Electronics and Battery Coding

Many modern German vehicles adjust their charging behavior based on stored battery data, and the 2008 Audi A6 is no exception. The points below summarize what owners should consider beyond just the physical replacement.

• Battery Energy Management (BEM): The A6 uses energy management software that can benefit from knowing the correct battery type and capacity.
• Coding or adaptation: On some models, when changing battery type (e.g., from flooded to AGM) or significantly altering capacity, it is recommended to update battery information in the control module via diagnostic tools (such as VCDS or similar).
• Matching specs: If you install a battery close to the original spec (same Ah, same technology type), the car will usually operate correctly even without coding, though best practice is to follow Audi’s procedures.
• Warning signs of mismatch: Repeated low-voltage warnings, unusual electrical behavior, or premature battery failure can indicate the need to verify coding or battery suitability.

While many owners replace batteries without coding and experience no immediate problems, aligning the stored battery data with the installed battery can optimize charging and battery lifespan.

How to Confirm the Correct Battery for Your Specific 2008 A6

Given minor differences between regions, trims, and service histories, the safest option is always to verify your car’s current requirement directly rather than relying solely on general model information.

Verification Steps for Owners

To make sure you obtain the correct size and spec, a few straightforward checks can help confirm fitment and compatibility.

• Check the existing battery label: Look for group designation (e.g., 94R, H7, 49, H8), Ah rating, and CCA figures printed on the top or side.
• Consult the owner’s manual: Audi’s manual for your exact trim often lists recommended capacity and sometimes battery type.
• Use reputable parts catalogs: Online catalogs from major brands (Bosch, Varta, Exide, Interstate, etc.) let you search by year, make, and model and typically list H7/H8 recommendations.
• Ask a dealer or Audi specialist: Providing your VIN allows them to look up the original factory specification for your car.
• Inspect physical dimensions: Measure length, width, and height if the existing battery may have been incorrectly fitted in the past.

Combining these checks ensures you not only match the intended size but also select a battery with appropriate performance characteristics for your specific A6 configuration.

Summary

The 2008 Audi A6 typically uses a large European-style battery in either BCI Group 94R (H7) or Group 49 (H8), with a capacity around 80–95 Ah and a CCA rating in the 720–850 range. Most owners will be well served by an H7 or H8 12‑volt battery—preferably AGM—that matches or slightly exceeds the original Ah and CCA specifications, fits securely in the trunk-mounted tray, and aligns with the vehicle’s energy-management system. Verifying the exact spec via the existing battery label, the owner’s manual, or a VIN-based parts lookup is the most reliable way to confirm the correct size for a given 2008 A6.

Which battery is used in the Audi A6?

Suitable batteries for AUDI A6 (Diesel) Passengers Vehicles

	AMARON PRO Automotive Battery – 600109087 (AAM-PR-600109087)
Item Code	AAM-PR-600109087
Model	600109087
Product Dimensions (LxBxH) (mm)	353x175x190
Voltage (V)	12

What battery does a 2008 Audi A4 take?

Duralast Group Size 94R H7 Battery H7-DL.

Is battery size 48 the same as H6?

For example there are the typical BCI Group Sizes used in the USA, but often the exact same Battery used in a European Car has a DIFFERENT name. For example the “Group48” size as it is called in the USA, is also called the “H6” Size by the European Manufacturers.

What size battery is in the 2007 Audi A6?

Duralast Group Size 49 H8 Battery H8-DL.