The 2009 Audi A4 uses a 12-volt automotive battery. Most non‑start‑stop A4s from that year rely on a standard maintenance‑free lead‑acid battery in the H6/Group 48 size. If your car is equipped with Audi’s Start‑Stop system or other energy‑recovery features, it may require an AGM (absorbent glass mat) 12‑volt battery with higher capacity. Always verify the exact specification from the owner’s manual or the battery label when replacing.
Battery types and options
Understanding the two main categories helps explain what you’ll need for a 2009 A4. The exact choice depends on engine, trim, and market. In general, non‑Start‑Stop models use a standard lead‑acid battery, while Start‑Stop equipped models demand an AGM battery to cope with frequent deep cycles and high electrical demand.
How to determine the exact battery in your car
Use the following steps to identify the exact battery specification for your car. The steps help you pick the correct size, type, and capacity for a replacement.
- Check the owner's manual for the exact group size, type, and specifications (12V, AGM if applicable).
- Inspect the battery label on the battery itself for the group size (such as H6/48), the CCA rating, and whether it indicates AGM.
- Look for Start‑Stop indicators or associated badges in the instrument cluster; Start‑Stop systems usually require an AGM battery.
- If in doubt, provide your VIN or engine code to a reputable parts retailer to confirm the correct replacement battery.
Following these steps will ensure you identify the correct battery specification for your 2009 Audi A4.
Typical configurations for the 2009 Audi A4
There are two main configurations based on whether the car has Start‑Stop. The following outlines the most common possibilities you may encounter in the 2009 A4 line.
Non-start-stop models (typical 2009 A4 without Start/Stop)
In this category, you’re likely dealing with a standard 12‑volt, maintenance‑free lead‑acid battery in a Group size commonly labeled H6 or 48. Key specs typically include:
- Group size: H6/48 (also labeled 48 in some markets)
- Battery type: maintenance‑free lead‑acid
- Voltage: 12V
- Capacity: roughly 60–70 Ah
- Cold‑cranking amps (CCA): roughly 600–750 A
- Orientation and venting consistent with standard automotive batteries
These cars generally accept OEM or reputable aftermarket replacements in the H6/48 size with similar CCA and capacity.
Start-stop capable models (with AGM)
For cars with Start‑Stop, or higher electrical load, the battery is typically AGM to handle frequent deep cycles and high current draws. Common attributes include:
- Battery type: AGM 12V
- Group size: often still H6/48, but some replacements use AGM versions designed for Start‑Stop
- Voltage: 12V
- Capacity: about 70–80 Ah
- CCA: commonly 760–800 A or higher depending on the exact battery
- Benefits: improved deep‑cycle endurance and reliability under stop‑start duty
Note: AGM batteries require compatible charging and electronics compatibility. Always verify the OEM specification for your exact model and market.
Summary
The 2009 Audi A4 typically uses a 12V battery. Non‑Start‑Stop versions usually take a Group 48/H6 maintenance‑free lead‑acid battery, while Start‑Stop equipped models require an AGM 12V battery with higher capacity. Always confirm the exact spec from your owner’s manual or battery label and choose a replacement from a reputable brand that matches the group size and AGM requirements if needed.