Which Battery Does the Audi A4 Use?

The Audi A4 typically uses a 12‑volt AGM (Absorbent Glass Mat) starter battery with specifications around 70–80 Ah and 680–800 A cold cranking amps, but the exact battery type, size, and technology vary by model year, engine, and equipment. To choose or replace a battery correctly, owners should match the original spec from the vehicle’s manual, the battery label, or a trusted parts catalog by VIN.

Understanding the Audi A4’s Battery System

The question of “which battery” the Audi A4 uses is more complex than naming a single model, because Audi has changed battery technologies, capacities and even physical sizes over the car’s generations. Modern A4s also integrate the battery into an energy-management system, sometimes with mild-hybrid technology, which makes correct type and proper coding important.

Battery Types Used in the Audi A4

Over the years, Audi has moved from conventional flooded lead‑acid batteries to enhanced types such as EFB and AGM, especially as start‑stop systems and energy management became standard. The following list outlines the main technologies you’ll find in recent A4 models.

• Conventional Flooded Lead‑Acid Battery: Found in older A4 models (primarily pre‑start‑stop). Less expensive but not ideal for frequent deep cycling.
• EFB (Enhanced Flooded Battery): Used in some models with basic start‑stop systems. More robust than standard lead‑acid, but generally a step below AGM for durability.
• AGM (Absorbent Glass Mat) Battery: Common on B8, B9 and current-generation A4s, especially those with start‑stop, higher electrical loads, or mild‑hybrid systems. Provides better deep‑cycle performance and vibration resistance.
• 12 V Lithium‑Ion Auxiliary Units (Selective): In some mild‑hybrid or performance variants, there may be additional lithium‑ion modules supporting the electrical system, though the primary starter battery is still a 12 V AGM in most cases.

In practice, most recent Audi A4s on the road today will require an AGM battery when replaced, and fitting a lower‑spec technology (like standard flooded) in a vehicle designed for AGM can shorten battery life and affect start‑stop performance.

How Battery Specification Varies by A4 Generation

Battery size and specification for the Audi A4 depend heavily on the platform generation (B6, B7, B8, B9, etc.), the engine (diesel vs petrol, four‑cylinder vs V6), climate package and optional equipment such as high‑power audio, adaptive suspension or auxiliary heaters.

B6 and B7 Audi A4 (Approx. 2001–2008)

The B6 and B7 generations typically use conventional flooded 12‑volt batteries with moderate capacities, as these cars were built before start‑stop became mainstream.

• Typical technology: Standard flooded lead‑acid battery.
• Common capacity range: Roughly 70–80 Ah, depending on engine and equipment.
• Cold cranking amps (CCA): Commonly in the 600–720 A range.
• Physical form factor: Often referred to in aftermarket catalogs as H6/L3 or H7/L4 (exact size varies by configuration and market).
• Location: Usually in the engine compartment for many markets, though some variants and regions may differ.

Owners of these earlier generations generally have more flexibility in choosing a replacement battery, but matching capacity and physical size remains essential.

B8 Audi A4 (Approx. 2008–2015)

With the B8 generation, Audi introduced more sophisticated energy management and, in many markets and trims, automatic start‑stop systems, which brought AGM batteries into mainstream use.

• Typical technology: AGM on most models with start‑stop; some lower‑spec or early B8 cars without start‑stop may use EFB or high‑spec flooded batteries.
• Common capacity range: Around 70–80 Ah (e.g., 70 Ah AGM; some high‑spec diesels or S4 models may use higher capacities, such as 80+ Ah).
• CCA range: Frequently around 680–800 A (EN), depending on the exact spec.
• Common aftermarket size codes:
  

  • Group H6 / L3 (around 278–280 mm length)
  • Group H7 / L4 (around 315 mm length) for higher‑capacity fitments

• Battery management: Equipped with an intelligent battery sensor on the negative terminal and central control unit that monitors state of charge and health.

On B8 models, sticking with AGM if the car was originally fitted with AGM is important for longevity and reliable operation of the start‑stop system.

B9 Audi A4 (Approx. 2016–Present)

The B9 platform and its facelifted versions have even more demanding electrical systems, and in many markets include 12‑volt mild‑hybrid technology on newer engines, further tightening battery requirements.

• Typical technology: AGM as standard on most B9 A4s, especially with start‑stop and/or mild‑hybrid system (MHEV). Some entry‑level non‑MHEV markets may use high‑spec EFB, but AGM is widely recommended.
• Common capacity range: Generally 70–80+ Ah for four‑cylinder models; higher‑output or diesel versions may use up to around 95 Ah depending on region and options.
• CCA range: Often in the 720–800+ A (EN) band.
• Form factor: Usually H6/L3 or H7/L4 AGM, but exact dimension must match the battery tray and clamp design.
• Mild‑hybrid variants: In addition to the conventional 12 V AGM starter battery, some models incorporate a separate 48 V battery for the belt‑starter generator system. This 48 V unit is different and not interchangeable with the 12 V starter battery.

For B9 A4s, correct specification and proper coding after replacement are essential, as the vehicle’s control modules closely track battery characteristics and charging strategy.

How to Identify the Correct Battery for Your Audi A4

Because Audi A4 specifications differ by year, engine, market, and equipment, the most reliable method is to check the actual car rather than relying only on model‑year tables. The following points explain how owners and technicians can pinpoint the right replacement.

• Check the existing battery label: The current battery usually lists capacity (Ah), CCA (EN), voltage (12 V), and technology (AGM, EFB, etc.), along with brand and part number.
• Consult the owner’s manual: Audi manuals typically specify the required capacity range, technology, and sometimes a VW/Audi part number for replacement.
• Use the VIN in a parts catalog: Online OEM parts sites or dealership systems can decode the car’s VIN to show the exact factory‑fitted battery spec and any superseded part numbers.
• Look at the battery tray and hold‑down: The physical mounting system and tray size constrain which battery lengths (H5/H6/H7, etc.) will fit safely and correctly.
• Check for start‑stop or mild‑hybrid features: If the car has automatic engine stop at traffic lights, or is labeled as “MHEV” / “mild‑hybrid,” an AGM (and possibly an additional 48 V battery) will almost certainly be required.

By verifying the original configuration with these steps, owners can avoid under‑specifying the battery, which could cause premature failure or system faults, and ensure that any replacement works seamlessly with the A4’s electronics.

Do Audi A4 Batteries Need Coding?

Modern Audi A4 models, especially from the B8 generation onward, often require battery coding or adaptation after replacement. This process tells the car’s energy management system that a new battery—with specific capacity and type—has been installed.

• Why coding is needed: The control unit tracks charging cycles, internal resistance, and state of health. Without resetting and informing it of the new battery type and capacity, the system may over‑ or under‑charge the new unit.
• Which models need it: Most A4s with a battery monitoring sensor and start‑stop, particularly B8 and B9, benefit from or require coding.
• How coding is done: Using a diagnostic tool (such as VCDS, ODIS, or other compatible scanners), technicians enter data like battery manufacturer code, serial number, and Ah rating, or select the correct replacement code.
• Consequences of skipping coding: Reduced battery life, irregular start‑stop behavior, warning messages, or inaccurate state‑of‑charge readings are possible if coding is omitted.

While very early A4s can accept a new battery without electronic adaptation, owners of newer models should plan for coding as part of a proper battery replacement procedure.

Key Specifications to Match When Choosing a Replacement

When selecting a new battery for any Audi A4, matching key specifications ensures compatibility and longevity. These criteria cover both electrical and physical requirements.

• Voltage: 12 V for the main starter battery on all Audi A4 models (separate 48 V battery only on certain mild‑hybrid systems).
• Capacity (Ah): Match or slightly exceed the original specification; typical ranges are around 70–80 Ah for many A4s, higher on some diesel or heavily optioned variants.
• Cold cranking amps (CCA): Equal to or greater than the original; higher CCA can improve cold‑start performance, especially in cold climates.
• Battery technology: Use AGM if the car was originally equipped with AGM, especially for start‑stop or mild‑hybrid systems; do not downgrade to standard flooded from AGM.
• Physical size and terminal layout: Ensure the battery fits the tray (e.g., H6/L3 or H7/L4) and has the correct terminal positions (usually European layout with positive on the right when facing the front of the battery).
• Brand and quality: Reputable manufacturers (such as Varta, Bosch, Exide, and OEM‑branded units) generally provide better performance and reliability.

By aligning a replacement battery with these parameters, Audi A4 owners can maintain the car’s designed performance and avoid electrical or fitment issues.

Summary

The Audi A4 uses a 12‑volt lead‑acid starter battery whose exact type and size depend on generation, engine, and equipment. Older A4s (B6/B7) generally employ conventional flooded batteries in the 70–80 Ah range, while most B8 and B9 models rely on AGM batteries of similar or slightly higher capacity to support start‑stop systems and advanced energy management. Many newer A4s also require electronic coding after battery replacement so that the vehicle recognizes the new unit and manages charging correctly. The most reliable way to identify the right battery is to check the existing battery label, consult the owner’s manual, or use the vehicle’s VIN in an OEM or reputable aftermarket catalog, then match voltage, capacity, CCA, technology, size, and terminal layout accordingly.

What kind of battery is in the 2014 Audi A4?

Duralast Gold Group Size 94R H7 Battery H7-DLG.

What type of battery does Audi use?

12V lead-acid battery
A 12V lead-acid battery is the most common type used in Audi A4 vehicles to start the engine and power electrical systems.

What kind of battery is in the Audi A4 2015?

Duralast Group Size 94R H7 Battery H7-DL.

What battery does the Audi A4 use?

Value Battery – Battery: H6 Group Size, 615 CCA, 765 CA, 95 Minute Reserve Capacity (Part No. 48H6-V)