2018 Ford F-350 Super Duty Battery Size & Group

Quick answer

• BCI Group Size: Group 65 (Gasoline), Group 31 (Diesel, dual-battery setup)
• CCA Rating: 850+ CCA for gasoline, 750+ CCA per battery for diesel
• Reserve Capacity: 150+ minutes for gasoline, 160+ minutes per battery for diesel
• AGM vs. Flooded: Both gasoline and diesel models can use either flooded lead-acid or AGM batteries. AGM is recommended for enhanced durability and longer life, especially with modern vehicle electronics.
• Terminal Layout: Top post (SAE terminals)
• Physical Dimensions: (Group 65) Varies slightly by manufacturer, but typically around 12" L x 7.5" W x 7.5" H. (Group 31) Typically around 13" L x 6.8" W x 9.4" H.
• Dual-Battery Setup: Diesel models come standard with a dual-battery setup for increased starting power and accessory support.

Replacement battery options

• Interstate:
  • Gasoline (Group 65): MTP-65 (Flooded), MTZ-65 (AGM)
  • Diesel (Group 31): 31-MHD (Flooded), 31-AGM (AGM)
• Optima:
  • Gasoline (Group 65 equivalent): YellowTop DH6 (AGM) - Note: Optima may list by direct fit or BCI equivalent, always confirm compatibility.
  • Diesel (Group 31 equivalent): YellowTop DH7 (AGM) - Note: Confirm fitment as Optima doesn't have a direct Group 31 often.
• DieHard:
  • Gasoline (Group 65): DieHard Platinum AGM Group 65, DieHard Gold Group 65 (Flooded)
  • Diesel (Group 31): DieHard Platinum AGM Group 31
• Odyssey:
  • Gasoline (Group 65): Odyssey Extreme Series ODX-AGM65 (AGM)
  • Diesel (Group 31): Odyssey Extreme Series ODX-AGM31 (AGM)
• ACDelco:
  • Gasoline (Group 65): ACDelco Professional AGM Group 65, ACDelco Professional Conventional Group 65
  • Diesel (Group 31): ACDelco Professional AGM Group 31, ACDelco Professional Conventional Group 31

Always verify part numbers and specifications with your retailer before purchase, as these can change.

AGM vs. flooded — which does this vehicle need?

The 2018 Ford F-350 Super Duty, whether equipped with the gasoline or diesel engine, can utilize either a traditional flooded lead-acid battery or an Absorbed Glass Mat (AGM) battery. However, for a heavy-duty truck like the F-350, an AGM battery often presents several advantages.

AGM batteries are designed to be more resistant to vibration, which is a significant factor in trucks that experience rough terrain or heavy hauling. They also offer a slower self-discharge rate and are less prone to sulfation, leading to a longer service life compared to flooded batteries. Furthermore, modern trucks are equipped with an increasing number of electronic accessories and computer modules that demand a consistent and robust power supply – an area where AGM batteries typically excel due to their higher sustained voltage.

While flooded batteries are generally more affordable upfront, the long-term benefits of an AGM battery in a 2018 F-350 often outweigh the initial cost difference, especially considering the critical role the battery plays in these hardworking vehicles.

Post-installation relearn / reset procedure

After disconnecting and replacing the battery in your 2018 Ford F-350 Super Duty, it's important to be aware of potential issues and a simple reset procedure. Modern vehicles rely on their powertrain control module (PCM) and other modules learning your driving habits. A battery disconnect can sometimes clear some of these learned parameters, leading to temporary odd behavior.

Here's a general procedure:

1. After Installation: Ensure all battery terminals are clean and securely tightened.
2. Initial Start: Start the engine and let it idle for 5-10 minutes without touching the accelerator. This allows the idle air control (IAC) valve and other sensors to re-learn their parameters.
3. Drive Cycle: Drive the vehicle normally for a few days, including a mix of city and highway driving. During this time, the vehicle's various modules will recalibrate. You might notice slightly different shift points, idle quality, or fuel economy initially, but this should resolve itself.
4. Window One-Touch Reset (If applicable): If your power windows lose their one-touch up/down feature, you may need to reset them. Roll the window all the way down, then hold the switch up until the window is fully closed and continue to hold for an additional 2-3 seconds. Repeat for all affected windows.
5. Radio Presets: You will need to reprogram your radio stations.

If you experience any persistent warning lights or significant operational issues after a few drive cycles, it may be necessary to have a professional shop diagnose the issue.

Signs of a failing battery

Recognizing the signs of a failing battery early can save you from being stranded. For your 2018 Ford F-350, keep an eye out for these indicators:

• Slow Cranking: The engine turns over sluggishly when you try to start it. This is often the most common and earliest sign.
• Dim Headlights/Interior Lights: When starting the truck, if your lights dim considerably, it indicates the battery is struggling to supply adequate power.
• Warning Lights: A "Check Engine" light or specific battery/charging system warning light on your dashboard could signal a problem.
• Corrosion: Excessive corrosion around the battery terminals can impede current flow and is often a sign of a leaking or overcharging battery.
• Swelling Battery Case: If the battery case appears swollen or bulging, especially on the sides, it's a sign of internal damage and requires immediate replacement.
• Electronic Glitches: Erratic behavior from electronics, such as the radio, navigation, or power windows, can sometimes point to an unstable power supply from a weak battery.
• Repeated Jumps: If your F-350 frequently needs a jump start, the battery is likely at the end of its life.

Common battery issues for this generation

The 2018 Ford F-350 Super Duty, like many modern heavy-duty trucks, places significant demands on its electrical system. Common battery issues for this generation often relate to these factors:

• Parasitic Draws: Modern trucks have numerous electronic modules that can draw small amounts of power even when the vehicle is off. If one of these modules malfunctions, it can create an excessive "parasitic draw" that drains the battery over time, especially during periods of inactivity.
• Accessory Use: With features like power running boards, numerous charging ports, advanced infotainment, and upfitter switches, extensive use of accessories while the engine is off can quickly deplete the battery.
• Harsh Environments: The F-350 is built to work, and operating in extreme hot or cold temperatures can significantly shorten battery life. Heat accelerates internal chemical reactions, while cold reduces a battery's available power.
• Charging System Issues: While not a battery fault itself, problems with the alternator or voltage regulator can lead to undercharging or overcharging, both of which will damage a battery prematurely.
• Diesel Starting Demands: Diesel engines require a much larger surge of power to crank over, especially in cold weather. This high demand means the dual batteries are worked harder, and any weakness in one battery can quickly affect the other.

Regular battery testing and maintenance, especially for diesel models, are crucial to extend battery life and ensure reliable starting.

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