2018 Peterbilt 579 Battery Size & Group

Quick answer

• BCI Group Size: Group 31
• Cold Cranking Amps (CCA): 950-1000 CCA per battery
• Reserve Capacity: 190-200 minutes per battery
• AGM vs. Flooded: Both AGM and flooded deep-cycle batteries are used, but AGM is recommended for its vibration resistance and maintenance-free design.
• Terminal Layout: Top post (SAE)
• Physical Dimensions: Approximately 13" x 6.8" x 9.5" (L x W x H)
• Dual-battery setup: Yes, typically a four-battery setup (two pairs of dual batteries) is used to provide the necessary power for this heavy-duty truck.

Replacement battery options

• Interstate: 31-AGM (AGM), 31-HD (Flooded)
• Odyssey: 31-PC2150S (AGM)
• ACDelco: 31-AGM (AGM)
• DieHard: 31-AGM (AGM)

AGM vs flooded — which does this vehicle need?

The 2018 Peterbilt 579 can use either AGM (Absorbent Glass Mat) or traditional flooded lead-acid batteries. However, given the high-vibration environment of a heavy-duty truck and the increasing electrical demands of modern vehicles, AGM batteries are the superior choice. They are sealed, spill-proof, and offer better vibration resistance, which translates to a longer service life in this application. While flooded batteries are less expensive upfront, they require regular maintenance (checking and topping off electrolyte levels) and are more susceptible to damage from vibration.

Post-installation relearn / reset procedure

There is no specific relearn or reset procedure required after a battery replacement on a 2018 Peterbilt 579. However, it's always a good practice to check that all electrical components are functioning correctly after the new batteries have been installed. This includes the radio, lights, and any other accessories.

Signs of a failing battery

• Slow engine crank: The engine turns over more slowly than usual when you try to start it.
• Dim lights and electrical issues: Headlights, interior lights, or other electrical components may be dim or flicker.
• Warning lights: The battery or check engine light may illuminate on the dashboard.
• Corrosion on terminals: A white, powdery substance around the battery terminals is a sign of corrosion, which can interfere with the electrical connection.
• Swollen or leaking battery case: If the battery case is swollen, cracked, or leaking, it needs to be replaced immediately.

Common battery issues for this generation

The most common battery issue for this generation of Peterbilt 579 is premature battery failure due to the high-vibration environment. This is why using high-quality, vibration-resistant AGM batteries is so important. Another common issue is parasitic draw, where an electrical component continues to draw power from the battery even when the truck is turned off. This can be caused by a faulty module, a short circuit, or an aftermarket accessory that has been improperly installed.

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