What Kind of Battery Does a BMW 328i Need?

A BMW 328i typically requires a 12‑volt AGM (Absorbent Glass Mat) battery with the correct physical size (group type), cold-cranking amps (CCA), and amp‑hour (Ah) rating specified for its model year—and it must be properly coded/registered to the car’s electronics after installation. While older models may use conventional flooded lead‑acid batteries, most modern 328i models (especially from the E90 generation onward) are designed for AGM batteries due to their electrical demands and start‑stop systems.

Why the “Right” Battery Matters in a BMW 328i

The BMW 328i is more sensitive to battery specifications than many non‑luxury cars because its electrical system is tightly integrated with the vehicle’s computer network. The battery type, capacity, and internal resistance are all taken into account by the power management system, which controls charging, start‑stop behavior (where equipped), and protection of electronic components. Using the wrong battery—or failing to code/register a new one—can lead to electrical errors, reduced battery life, and in some cases limp‑mode behavior.

Battery Type by Generation and Model Year

Different generations of the BMW 328i use slightly different battery specifications. Understanding which generation you own is the starting point for choosing the correct battery.

E46 3 Series (Approx. 1999–2006, US: 1999–2005 for 328i/330i)

The E46‑generation 3 Series—older 3ers that still sometimes carry a 328i badge in certain markets—typically came with conventional flooded lead‑acid batteries rather than AGM. They still benefit from quality, but the electrical system is less demanding than newer generations.

Here is an overview of what E46‑era 3 Series typically use in terms of battery specifications (note that exact specs can vary slightly by engine, equipment level, and climate):

• Battery type: Flooded lead‑acid (conventional), though AGM is often an acceptable upgrade.
• Voltage: 12 V.
• Typical size group (North America): Group 94R (also known as H7) or Group 49/H8 for some trims.
• Capacity: Usually in the 70–90 Ah range.
• Cold‑Cranking Amps (CCA): Commonly 700–900 CCA depending on brand and model.

In practice, owners of E46‑era cars can often choose between premium flooded or AGM batteries as long as size and capacity are correct; coding/registration is not as critical as it is on later models, though it is still a good idea on very late E46s with more advanced electronics.

E90/E91/E92/E93 328i (Approximately 2006–2013)

The E90‑generation 328i, especially from around 2007 onward, is where battery choice becomes much more specific. BMW began to use intelligent battery sensors (IBS) and more sophisticated power management, and many cars in this generation are best served by AGM batteries.

Key characteristics of the battery used in an E90‑series 328i include the following items, which illustrate the growing electrical demands of this generation:

• Battery type: AGM is often specified, especially for vehicles with many electrical options or start‑stop (on some markets). Some trims shipped with high‑quality flooded batteries, but AGM is frequently recommended as a replacement.
• Voltage: 12 V.
• Size group (North America): Commonly Group 94R (H7) or Group 49 (H8), depending on equipment.
• Capacity: Typically 70–90 Ah; 80 Ah AGM is a popular spec for many 328i models.
• CCA: Usually 720–900 CCA to ensure reliable cold starting.

For these models, simply matching physical size and CCA is not enough; BMW’s power management requires the battery to be “registered” (and sometimes “coded” for a different type or capacity) so the alternator charges it correctly and the car knows a new battery has been installed.

F30/F31 328i (Approximately 2012–2016)

The F30‑generation 328i, the turbocharged four‑cylinder model most buyers know from the 2010s, is heavily dependent on robust electrical support and almost universally uses AGM batteries. Many F30 328i models also feature auto start‑stop, which dramatically increases cycling demands on the battery.

The F30/F31 328i battery specifications can be summarized as follows, reflecting the typical configuration most owners will encounter:

• Battery type: AGM only in most markets; this is the preferred and often required technology.
• Voltage: 12 V.
• Size group (North America): Typically Group 94R (H7). Some variants can use Group 48 (H6) in specific configurations, but 94R/H7 is most common.
• Capacity: Commonly 80–92 Ah for OEM‑spec AGM units.
• CCA: Roughly 760–900 CCA, depending on brand and exact battery model.

Because the F30 platform integrates features like energy recuperation, intelligent alternator control, and start‑stop, using the correct AGM battery and properly registering/coding it after installation is essential to avoid electrical faults and premature battery wear.

Regional Differences and Petrol vs Diesel Variants

In some markets, BMW sold 3 Series diesels or different trim combinations under similar badge names. These variants can require slightly higher capacity or CCA batteries due to glow plugs and higher compression engines. Badge names can also differ by region, so a “328i” in one market may have a different drivetrain from another.

The following points summarize why you should not rely solely on the “328i” label and should instead check detailed specifications:

• Engine type: Diesel variants often need higher CCA and sometimes larger capacity batteries.
• Climate: Cold regions benefit from higher CCA ratings than warm regions.
• Equipment level: Cars with heated seats, premium audio, and numerous power options draw more current.
• Market differences: OEM battery part numbers and recommended sizes can vary by country.

Because of these factors, checking the exact VIN‑specific data or the battery label currently installed in your car is the most reliable way to confirm the required battery specification.

AGM vs Flooded Lead‑Acid: Why BMW Often Chooses AGM

Many modern BMW 328i models are specified with AGM batteries, which are more advanced than conventional flooded batteries. The choice of AGM is directly related to how sophisticated the electrical system has become and how many charging cycles the battery must endure.

Key Differences Between AGM and Flooded Batteries

The following comparison highlights why AGM is now the default or recommended choice for many 328i models, especially those with start‑stop and high electrical loads.

• Deep‑cycle capability: AGM batteries tolerate frequent charge/discharge cycles better, ideal for start‑stop driving.
• Vibration resistance: AGM construction is more robust, advantageous in performance‑oriented cars.
• Spill‑proof design: Electrolyte is absorbed in glass mats, making AGM safer in trunk‑mounted applications (like the 3 Series).
• Charge acceptance: AGM batteries can accept higher charge currents, which pairs well with intelligent alternator systems.
• Cost: AGM batteries are usually more expensive than equivalent flooded units.

While earlier BMW 328i models can function well with high‑quality flooded batteries, newer generations—especially F30 and any car with start‑stop—are engineered around AGM behavior and should not be downgraded to conventional flooded designs.

Battery Size, Ah Rating, and CCA: What the Numbers Mean

Beyond the basic battery type, three technical metrics are critical: physical group size, amp‑hour (Ah) rating, and cold‑cranking amps (CCA). Matching or closely aligning with BMW’s factory specifications ensures long life and reliable operation.

Physical Group Size (H6, H7, H8, etc.)

In North America, BMW batteries are usually described by BCI group numbers (such as 48/H6, 94R/H7, or 49/H8). In Europe, you may see DIN/EN designations. The physical group defines length, width, height, and terminal positions.

These aspects of group size influence fitment and safety within the battery compartment of a 328i:

• Dimensions: The battery must physically fit the battery tray in the trunk (or under the hood on some older models).
• Terminal layout: “R” in 94R indicates reversed terminals, which must match BMW’s cable layout.
• Hold‑down compatibility: The case must have the correct lip/edge so the factory clamp can secure it.
• Clearance: A battery that’s too tall risks contact with metal components or trim.

Most modern 328i models use Group 94R/H7 in North America, though Group 49/H8 or Group 48/H6 may appear in some trim levels and markets; always compare with the existing battery and the vehicle’s documentation.

Amp‑Hour (Ah) Capacity

The Ah rating describes how much energy the battery can store—important for long parking periods, accessory use, and overall electrical stability. BMW calibrates its charging strategy to a specific Ah capacity.

When selecting the Ah rating for a BMW 328i battery, consider the following guidelines to stay close to OEM design:

• Match OEM when possible: If the original battery is 80 Ah AGM, replacing with 80 Ah AGM is ideal.
• Do not undersize: Dropping significantly below the OEM Ah rating risks weak starting and short battery life.
• Modest oversizing can be acceptable: Slightly higher Ah (e.g., 90 Ah instead of 80 Ah) is usually fine if properly coded.
• Registration/coding required: The car’s charging algorithm must know the new capacity to avoid under‑ or over‑charging.

Because the BMW 328i relies on sophisticated power management, the Ah rating is not just a comfort feature; it’s a core part of how the alternator and IBS sensor manage charging behavior.

Cold‑Cranking Amps (CCA)

CCA defines the battery’s ability to provide starting current in cold conditions. It matters most in cold climates and for higher‑compression engines such as diesels, but it is still a key spec for any 328i.

When checking the CCA rating for a replacement battery, these points help ensure the car starts reliably in all temperatures:

• Equal or higher CCA than OEM: Avoid choosing a battery with lower CCA than the original equipment.
• Climate‑specific choices: In very cold regions, selecting a battery at the upper end of CCA ranges is beneficial.
• Brand variations: Different manufacturers list slightly different CCA for similar batteries; focus on meeting or exceeding BMW’s baseline.
• Balance with Ah: Extremely high CCA with a low Ah rating is not ideal; both metrics should be in a sensible range.

For most gasoline 328i models, a CCA range of roughly 720–900 is typical for OEM‑grade batteries, with higher values offering more margin in harsh winter conditions.

Battery Registration and Coding: Critical for Modern 328i Models

On E90 and especially F30‑generation BMW 328i models, simply swapping a battery without telling the car can cause significant issues. BMW uses an Intelligent Battery Sensor (IBS) and a digital power management system that tracks battery age, charge cycles, and condition.

What Is Battery Registration?

Battery registration informs the vehicle’s control module that a new battery has been installed. This resets internal aging parameters and ensures the charging algorithm is appropriate for a fresh battery.

Key aspects of battery registration for a BMW 328i include the following operational and practical considerations:

• Resetting adaptation values: The car stops treating the battery as “old” and adjusts charging behavior.
• Preventing overcharging: Without registration, the alternator might continue to charge aggressively, shortening the new battery’s life.
• Preventing undercharging: If the system misjudges the battery state, it might under‑charge it, leading to repeated low‑voltage events.
• Error reduction: Registered batteries are less likely to trigger low‑voltage codes and intermittent electronic faults.

Registration is done via specialized tools (BMW ISTA, ISTA‑P, or high‑quality aftermarket scan tools and apps) and typically takes only a few minutes once the right equipment is connected.

What Is Battery Coding and When Is It Needed?

Battery coding is distinct from registration: it is required when you change the battery type (e.g., flooded to AGM) or significantly change Ah capacity. In such cases, the control unit must be told about the new battery characteristics.

These are the key scenarios that usually require coding, rather than simple registration, in a BMW 328i:

• Type change: Switching from conventional flooded to AGM or vice versa.
• Capacity change: Moving from, for example, 70 Ah to 90 Ah or similar significant jumps.
• OEM to non‑OEM changes: Some aftermarket sizes that differ from BMW’s stored profiles may necessitate coding.
• Retrofits or upgrades: Installing a battery from a different group size or with markedly different specs.

Failing to code when required can result in chronic over‑ or under‑charging and may shorten the life of a new battery, especially AGM units that are more sensitive to incorrect charge profiles.

How to Confirm the Correct Battery for Your Specific BMW 328i

Because there are year‑to‑year, market, and equipment differences, the best way to know exactly what battery your 328i needs is to check both physical and digital references tied to your particular vehicle.

Check the Existing Battery and Owner Information

Start by examining what is already installed. The factory or previous‑owner battery often provides a close reference to what you should buy, though confirm it is correct and not an old mis‑match.

When you inspect your existing battery and documentation, look for the following pieces of information to guide a replacement choice:

• Label details: Type (AGM or flooded), Ah rating, CCA, and brand printed on the battery label.
• Case size: Compare the shape and dimensions to standard groups like H6/H7/H8.
• Owner’s manual: Many manuals list recommended battery capacity and sometimes type.
• Trunk or under‑hood stickers: Some cars have a label showing original battery specs or part numbers.

If the currently installed battery’s specifications differ from what the manual or trunk label indicates, assume the official documentation is the authoritative source and confirm with a parts catalog or dealer.

Use VIN‑Based Parts Catalogs or a BMW Dealer

Your BMW’s Vehicle Identification Number (VIN) is the most precise way to determine original battery specifications. Official BMW systems and reputable online catalogs can decode the VIN and list factory‑specified parts.

Using VIN‑based resources gives you the following advantages over guesswork or generic fitment charts:

• Exact OEM part number: Identifies the original battery, including type and capacity.
• Regional accuracy: Accounts for market‑specific differences in electrical options.
• Option‑based fitment: Adjusts for high‑equipment models versus base trims.
• Start‑stop compatibility: Confirms whether the car was built with systems that mandate AGM batteries.

If there is any doubt—especially in vehicles that have been modified or imported—VIN‑based information from a BMW dealer or a trusted online OEM parts source is the safest reference for battery choice.

Brand Choices and Aftermarket Options

Once you know the type, size, and capacity your 328i requires, you will find many aftermarket and OEM‑equivalent brands available. Quality and specification match should take precedence over brand loyalty alone.

What to Look for in a Replacement Battery Brand

Modern BMWs are demanding on batteries, so choosing a reputable manufacturer and a product line that meets or exceeds OEM specifications is important for reliability.

When comparing potential battery brands and models for your BMW 328i, keep these selection criteria in mind to ensure performance and longevity:

• OEM or OEM‑equivalent: Brands that supply batteries to BMW or other German manufacturers are often a safer bet.
• AGM quality: If AGM is required, ensure the brand’s AGM line has a record of reliability, not just the cheapest option.
• Correct labeling: Confirm Ah rating and CCA are clearly stated and match BMW’s requirements.
• Warranty: Look for a solid warranty term that reflects confidence in the product, especially for AGM units.

Well‑regarded brands in many markets include Exide, Varta, Bosch, East Penn/Deka (often sold as OEM or private labels), and high‑tier lines from major retailers, provided the specs and form factor are correct for your 328i.

Practical Installation Considerations

Replacing the battery in a BMW 328i involves more than lifting out the old one and dropping in a new one, particularly for trunk‑mounted batteries and those integrated with IBS sensors. Careful handling protects both the car and the new battery.

Key Steps and Precautions

While specific procedures vary slightly by generation, several general safety and procedural points apply to most 328i models and help avoid accidental damage.

• Power down: Turn off all electronics, remove the key/fob, and wait a few minutes before disconnecting.
• Disconnect negative first: Always remove the negative terminal before the positive to reduce short‑circuit risk.
• Protect IBS: If your car has an Intelligent Battery Sensor on the negative cable, handle it carefully and do not bypass it.
• Secure the new battery: Use the correct hold‑down brackets to prevent movement during driving.
• Register/code afterward: Use a capable diagnostic tool or have a shop register (and if needed, code) the new battery.

Owners comfortable with DIY work can physically swap the battery themselves and then either use a compatible OBD tool or visit a shop solely for registration/coding; this often reduces overall replacement cost while maintaining correct system configuration.

Summary: The Right Battery for a BMW 328i

A BMW 328i needs a correctly sized 12‑volt battery—typically an AGM unit for E90 and especially F30 generations—with the proper group size (commonly 94R/H7), amp‑hour capacity (often 70–92 Ah), and adequate CCA (roughly 720–900). Older 3 Series models can use quality flooded lead‑acid batteries, but many later 328i cars are engineered around AGM technology, particularly those with auto start‑stop and advanced power management.

The most reliable way to select the correct battery is to check your specific model year and market via the VIN, confirm the original specs, and then choose a reputable brand that matches type, size, Ah, and CCA. For E90 and F30 generations, it is crucial to register—and, if changing type or capacity, code—the new battery so the car’s charging system works as designed. With the right battery correctly installed and configured, a BMW 328i will start reliably, protect its electronics, and maximize the service life of the new battery.

How much is a battery for a BMW 328i?

between $383 and $434
The average cost for a BMW 328i Battery Replacement is between $383 and $434. Labor costs are estimated between $109 and $160 while parts are typically priced around $274.

Which battery is used in the BMW 3 series?

Suitable batteries for BMW 3 Series (Diesel) Passengers Vehicles

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

Do BMWs require special batteries?

Depending on vehicle specifications, a battery from a specific tier may be required. Please see your authorized BMW Center for details. All work is carried out by BMW Trained Technicians using Original BMW Parts, which come with a two-year unlimited mileage limited warranty.

What type of battery does a BMW 328i use?

DieHard Platinum AGM – Battery: H6 Group Size, 4 Year Warranty, 760 CCA, 950 CA, 120 Minute Reserve Capacity (Part No. H6-AGM)