2017 Peterbilt 579 Battery Specs & Replacement

Quick answer

• BCI Group Size: Group 31
• Cold Cranking Amps (CCA): 950 CCA is standard, but higher is acceptable.
• Battery Type: AGM (Absorbed Glass Mat) is highly recommended over standard flooded batteries.
• System: 12-volt system, typically utilizing four batteries wired in parallel for a total of 3800 CCA.
• Terminal Layout: SAE Post (standard "top post")
• Dimensions (approximate): Length: 13", Width: 6.8", Height: 9.5"

Replacement battery options

• Interstate: 31-AGM7 (925 CCA)
• Odyssey: 31-925S (925 CCA, 205 RC)
• ACDelco: 31-900AGM (900 CCA)
• DieHard: Platinum AGM Group 31 (1000 CCA)

AGM vs flooded — which does this vehicle need?

AGM (Absorbed Glass Mat) batteries are the strong recommendation for a 2017 Peterbilt 579. While you can technically use older-style flooded lead-acid batteries, it's not advisable for a modern heavy-duty truck. The 579 has numerous electronic modules, an infotainment system, and often an inverter for hotel loads, all of which place significant demands on the electrical system even when the engine is off. AGM batteries are better suited to handle these deep-cycle demands and are more resistant to vibration, a constant in the life of a commercial truck.

Post-installation relearn / reset procedure

A major benefit of the Peterbilt 579 is its robust electrical system that does not require a specific reset or relearn procedure after a battery replacement. The truck's Engine Control Module (ECM) and other computers will recognize the new power source without special tools. However, you may lose trip data, fuel economy averages, and radio presets. It is always a good practice to ensure all accessories are turned off before disconnecting the batteries to prevent any potential electrical arcs or damage to sensitive electronics.

Signs of a failing battery

• Slow Engine Crank: If the starter motor turns over more slowly than usual, it's a primary symptom of weak batteries.
• "Low Voltage" warnings: The driver information center may display a "Low Voltage" alert if the system detects a drop in power.
• Dimming Lights: Headlights or interior lights that dim significantly during engine cranking point to a lack of battery power.
• Corrosion on Terminals: White or blueish powder around the battery posts is a sign of leaking acid and a failing seal, which can inhibit electrical flow.
• Swollen Battery Case: If the sides of the battery are bulging, it's a sign of internal damage and the battery should be replaced immediately.

Common battery issues for this generation

The 2017 Peterbilt 579 is known for having a significant parasitic draw on its batteries, especially on trucks equipped with APUs (Auxiliary Power Units) and extensive "hotel" features like inverters, refrigerators, and microwaves. If one battery in the four-pack fails, it will quickly drain the others. It is critical to replace all four batteries at the same time to ensure the pack is balanced and to prevent premature failure of the new batteries. Using a battery isolator and ensuring all connections are clean and tight can help mitigate some of these common issues.

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