The 2018 Mercedes C300 uses a 12-volt AGM (absorbed glass mat) battery designed to power the starter and the car’s start-stop system.
The exact specifications can vary by market and option level, but this model relies on a dedicated 12V lead-acid battery (AGM) rather than a standard flooded unit. Replacement should use an AGM battery with the correct group size and MB-approved specifications for your VIN, as the location and exact capacity can differ by configuration.
Battery type and specs
Here are the key characteristics typically associated with the 12V AGM battery in the 2018 C300. Note that exact numbers can vary by market and equipment.
- Battery type: 12-volt lead-acid, AGM (not a standard flooded battery)
- Technology: Absorbent Glass Mat (AGM) to support start-stop and high electrical demand
- Typical capacity: approximately 60–80 Ah (varies by configuration)
- Cold-cranking amps (CCA): commonly in the ~680–760 A range
- Replacement note: use an MB-approved AGM battery with the correct group size for your VIN
In practice, always verify the exact group size, CCA, and capacity on the battery label or via a VIN-based parts lookup before purchasing a replacement.
How to identify the correct battery for your car
To ensure you buy the right battery for your 2018 C300, follow these steps. They help confirm the exact MB specification for your vehicle.
- Check the battery label in your car for group size (e.g., 48/49), CCA, and AGM designation
- Use the vehicle identification number (VIN) to look up the exact MB battery part number from official MB parts resources
- Prefer an OEM MB AGM battery or an approved aftermarket AGM that meets MB specifications for stop-start systems
- Confirm the battery location and mounting requirements if you are purchasing a replacement kit or relocating the battery
Verifying the exact spec ensures compatibility with the car’s electrical system and avoids issues with the start-stop and memory functions.
Maintenance and replacement tips
Proper care helps maximize life and performance for the 12V AGM battery in a 2018 C300.
- Inspect terminals for corrosion and ensure clamps are tight; clean with a non-acidic cleaner if needed
- Use a battery maintainer or trickle charger if the car will be idle for extended periods
- Avoid deep discharges; if resting voltage falls consistently below ~12.4 V, consider testing or replacement
- When replacing, choose an AGM battery with MB approval and confirm it matches the model’s group size and CCA
Following these tips helps maintain electrical reliability, particularly with the high demand from the C-Class’ electronics and start-stop feature.
Summary
In short, a 2018 Mercedes C300 uses a 12-volt AGM battery designed for start-stop systems. Exact group size, capacity, and CCA vary by market and equipment, so always verify specs on the battery label or via VIN-based part lookup and opt for an MB-approved AGM replacement. Regular maintenance and proper replacement ensure reliable starting power and electronic performance.