What Size Battery Is in the 2017 Audi A4?

The 2017 Audi A4 typically uses a 12‑volt AGM (Absorbent Glass Mat) battery in Group Size H6 (also known as Group 48), with a capacity of around 70–80 Ah and a cold cranking amps (CCA) rating in the 680–800 CCA range, depending on trim and market. This article explains the standard battery specifications, variations by engine and equipment, and what you should know when replacing the battery.

Understanding the 2017 Audi A4 Battery Specification

The 2017 Audi A4 (B9 generation) was designed with a modern electrical system that supports features such as start‑stop, advanced infotainment, and driver‑assistance electronics. As a result, Audi equips most A4 models with an AGM battery, which is more robust and better suited to frequent cycling than a traditional flooded lead‑acid battery.

Typical Factory Battery Type and Size

While exact factory fitment can vary slightly by region, engine, and equipment level, the mainstream configuration for the 2017 Audi A4 sedan and Avant is broadly consistent. The critical details are the physical size (group), technology type, and electrical capacity, which ensure compatibility with the vehicle’s energy management system.

The main characteristics of the factory‑style battery installed in a 2017 Audi A4 are generally as follows:

• Battery technology: AGM (Absorbent Glass Mat)
• Nominal voltage: 12 V
• BCI / DIN group size: H6 / 48 (commonly labeled as Group 48 or L3 in some catalogs)
• Capacity: Approximately 70–80 Ah (ampere‑hours), with many OEM units around 72–75 Ah
• Cold Cranking Amps (CCA): Typically about 680–800 CCA, depending on market and supplier
• Polarity / terminal layout: Standard European layout, top posts, with positive terminal usually on the right when facing the front of the car
• Location: In the engine bay, usually on the passenger side (left/right depends on LHD vs RHD markets)

Taken together, these specifications ensure the battery can deliver reliable cold starts, power the car’s electronics, and integrate correctly with Audi’s battery monitoring and energy management systems.

Why Group Size H6 (48) Is the Common Fit

Battery “group size” refers to the physical dimensions and terminal configuration of the battery. The 2017 Audi A4’s battery tray and hold‑down system are designed around the H6/Group 48 footprint, which provides a balance of capacity and compactness suitable for its engine range.

Physical Dimensions and Fitment

The H6/Group 48 battery size is widely used in modern European sedans and crossovers. For the 2017 Audi A4, this size aligns with the available space in the engine bay and the cable routing to the positive and negative terminals.

Typical dimensions for a Group H6 (48) battery are:

• Length: About 278–283 mm (10.9–11.1 inches)
• Width: About 174–175 mm (6.9 inches)
• Height: About 188–190 mm (7.4–7.5 inches)

These dimensions give owners and technicians a clear benchmark when sourcing an aftermarket replacement, ensuring the new unit fits safely under the factory hold‑down and allows the hood to close without interference.

Electrical Capacity: Ah and CCA Ratings

The 2017 Audi A4’s electrical demands are higher than those of older cars, making ampere‑hour capacity (Ah) and cold cranking amps (CCA) important considerations when choosing a battery.

Ampere‑Hour (Ah) Capacity

The Ah rating indicates how much energy a battery can store and deliver over time. For this generation of A4, Audi’s typical specification is in the low‑ to mid‑70 Ah range.

For most 2017 A4 models, owners can expect these approximate capacity specifications:

• Standard petrol (gasoline) engines: Around 70–75 Ah
• Diesel variants (TDI), where applicable: Often toward the higher end, 75–80 Ah, especially in colder‑climate markets
• Heavily optioned vehicles (advanced driver assists, upgraded audio): Usually still in the 70–80 Ah band, but dealers may favor higher‑capacity units

Staying within this Ah range helps ensure the vehicle’s start‑stop, comfort, and safety systems operate reliably, especially when the engine is off but electrical loads remain active.

Cold Cranking Amps (CCA)

CCA measures a battery’s ability to start an engine in cold conditions. For the 2017 Audi A4, the OEM and high‑quality aftermarket AGM batteries generally fall between about 680 and 800 CCA.

Typical CCA ranges for 2017 A4 configurations include:

• Base petrol engines (e.g., 2.0 TFSI in many markets): Around 680–730 CCA
• Higher‑output or diesel engines: Frequently 730–800 CCA, depending on region and supplier
• Cold‑climate packages: Often specified at the upper end of the CCA range for improved winter starting

Choosing a replacement battery with equal or slightly higher CCA than the original is generally recommended, especially if you live in a region with harsh winters.

AGM vs. Conventional Lead‑Acid Batteries

A key distinction for the 2017 Audi A4 is the use of AGM technology, which differs significantly from older flooded batteries. The vehicle’s charging and energy management systems are calibrated for AGM behavior.

Why Audi Uses AGM in the 2017 A4

AGM batteries are designed to withstand frequent charge‑discharge cycles and higher auxiliary loads, both of which are common in modern vehicles with start‑stop and heavy electronics use.

Some of the main advantages of AGM batteries in the 2017 A4 context are:

• Better cycle life: AGM can handle more deep discharge cycles, ideal for start‑stop operation.
• Improved vibration resistance: Beneficial for long‑term durability in everyday driving.
• Lower self‑discharge: Holds charge better during periods of infrequent use.
• Spill‑proof design: Electrolyte is absorbed in fiberglass mats, reducing leakage risk.
• Faster recharge efficiency: Works well with smart alternators and energy management systems.

Because the Audi A4’s system is tuned for AGM, switching to a conventional flooded battery can lead to shorter battery life and potential issues with start‑stop or battery monitoring accuracy.

Variations by Market, Engine, and Trim

While H6/Group 48 AGM is the prevailing fitment, there are minor variations depending on the exact 2017 A4 you own and where it was sold. Factors like engine type, equipment level, and climate package can influence the precise OEM part number and capacity.

Influence of Engine and Equipment

Different engines and equipment packages may feature slightly different factory battery specifications, though they usually remain within the same physical group size.

Typical patterns across 2017 Audi A4 variants include:

• 2.0 TFSI petrol (quattro and FWD): Almost always Group H6/48 AGM with 70–75 Ah capacity.
• 2.0 TDI diesel models (where offered in 2017): Often similar size but sometimes spec’d at the higher Ah/CCA end for cold starts.
• S line / high‑equipment trims: Same group size; some markets may specify slightly higher‑capacity batteries to support more onboard electronics.
• Allroad / Avant variants: Usually share the same battery group and technology, though check the exact part number for diesel vs. petrol.

In practice, these variations rarely change the group size; they mostly affect the precise Ah and CCA ratings and the OEM label on the battery.

Checking Your Specific Vehicle’s Battery

Because regional specifications can differ and prior owners may have replaced the original battery, confirming what is in your individual car is important before ordering a new one.

How to Verify the Battery Size and Rating

Looking at your current battery and checking official documentation are the most reliable ways to confirm the exact specification Audi intended for your A4.

Practical steps to identify the correct battery for a 2017 Audi A4 include:

• Check the existing battery label: Look under the hood for markings like “AGM,” “H6,” “48,” capacity (e.g., 72 Ah), and CCA (e.g., 730 A EN).
• Consult the owner’s manual: The battery section usually lists the required specification and technology type.
• Use the VIN at a dealer or parts site: Audi dealers and reputable online catalogs can decode your VIN to show the original battery spec.
• Inspect the battery tray and hold‑down: Ensures an H6/48 footprint is indeed what the car was designed for, confirming fitment.

By cross‑checking these sources, you minimize the risk of buying a battery that doesn’t fit physically or fails to meet the electrical demands of your specific configuration.

Key Considerations When Replacing the Battery

Modern Audis, including the 2017 A4, incorporate battery monitoring systems that track state of charge and age. When the battery is replaced, proper installation and, ideally, electronic adaptation are important to maintain system accuracy and performance.

Installation, Coding, and Choices

A do‑it‑yourself owner can often physically replace the battery, but the car’s software may still need to be informed that a new battery has been installed. This is especially relevant on vehicles with start‑stop and advanced energy management.

When replacing a 2017 Audi A4 battery, keep these points in mind:

• Match AGM technology: Always use an AGM battery to align with the factory design and control system.
• Stay with H6/Group 48 size: This ensures correct fit in the tray and proper use of the hold‑down clamp.
• Meet or exceed OEM Ah and CCA: Choose a quality unit with at least the same ratings as the original to avoid performance issues.
• Consider battery registration/coding: Many workshops use diagnostic tools (e.g., VCDS, ODIS) to register the new battery so the energy management system can recalibrate.
• Preserve settings if possible: Using a memory saver during replacement can help retain radio presets, clock, and some module settings.

Following these steps reduces the risk of electrical warnings, premature wear on the new battery, and glitches in features like start‑stop or comfort electronics.

Summary

The 2017 Audi A4 is typically equipped with a 12‑volt AGM battery in Group Size H6 (Group 48), with a capacity of about 70–80 Ah and a CCA rating around 680–800 A, depending on engine and market. This configuration balances physical fitment in the engine bay with the electrical demands of a modern, feature‑rich sedan. While minor differences in capacity and CCA exist across regions and trims, sticking to an AGM H6/48 battery that meets or exceeds the original specifications—and, where possible, having it properly registered in the vehicle’s system—will ensure reliable starts and stable operation of the A4’s electronics.