2024 Peterbilt 389 Battery Size & Group

Quick Answer

• BCI Group Size: Group 31 (typically three to four batteries)
• CCA Rating: 925-1150 CCA per battery (minimum, consult owner's manual for exact requirements)
• Reserve Capacity (RC): 180-220 minutes per battery
• AGM vs. Flooded: Flooded lead-acid is standard, but AGM is an upgrade option for improved lifespan and vibration resistance.
• Terminal Layout: Typically SAE (post) terminals, top-post design.
• Physical Dimensions (Group 31): Approximately 13" L x 6.8" W x 9.4" H
• Dual-Battery Setup: The Peterbilt 389, like most heavy-duty trucks, uses a multi-battery setup (usually 3-4 Group 31 batteries) wired in parallel to achieve the necessary cranking power for its large diesel engine and accessories.

Replacement Battery Options

Given the heavy-duty nature and significant power requirements of a 2024 Peterbilt 389, Group 31 batteries are the standard. Here are some popular options:

• Interstate: 31-MHD (Flooded), 31-AGM7 (AGM)
• Odyssey: 31-PC2150S (AGM)
• ACDelco: 31P-950 (Flooded), 31AGM (AGM)

AGM vs Flooded — Which Does This Vehicle Need?

The 2024 Peterbilt 389 typically comes equipped with flooded lead-acid batteries from the factory, and these will meet the vehicle's needs under normal operating conditions. Flooded batteries are a cost-effective and reliable choice for most applications.

However, Absorbed Glass Mat (AGM) batteries offer several advantages that might make them a worthwhile upgrade for a heavy-duty truck like the 389:

• Improved Vibration Resistance: Trucking inherently involves a lot of vibration, and AGM batteries are better designed to withstand this, potentially leading to a longer lifespan.
• Enhanced Deep Cycling Capabilities: If your truck spends extended periods idling, running auxiliary power units (APUs), or powering various electronic accessories, an AGM battery can handle deeper discharges and recharge cycles more effectively.
• Leak-Proof and Maintenance-Free: AGM batteries are sealed, eliminating the need for periodic water checks and reducing the risk of acid leaks, which is beneficial in a commercial vehicle application.
• Higher Cranking Power: While flooded batteries provide sufficient power, AGMs often deliver superior cold cranking amps and maintain voltage better in cold weather.

Ultimately, while flooded batteries are perfectly acceptable, an AGM upgrade can offer greater durability, reliability, and performance, especially for trucks operating in demanding conditions or with significant auxiliary power demands.

Post-Installation Relearn / Reset Procedure

For a heavy-duty truck like the 2024 Peterbilt 389, the post-battery installation relearn or reset procedure is generally less complex than on modern passenger vehicles, which often have intricate electrical systems sensitive to power interruptions. However, a few considerations are important:

1. Engine ECU and Other Modules: Most modern truck ECUs (Engine Control Units) and other control modules are designed to retain their learned parameters through power interruptions. You typically won't need a specific