2019 Kenworth T680 Battery Size & Group

Quick Answer

• BCI Group Size: Group 31 (typically three or four batteries)
• CCA Rating: 925-1000 CCA per battery (minimum for a single battery; total system CCA will be higher)
• Reserve Capacity: 180-200 minutes per battery
• AGM vs. Flooded: While flooded lead-acid batteries are standard, AGM (Absorbent Glass Mat) batteries are a popular upgrade for their durability and deeper discharge cycles, especially for auxiliary power units (APUs) or extensive electronic loads.
• Terminal Layout: Typically SAE posts with threaded studs for secure connections.
• Physical Dimensions (Group 31): Approximately 13" L x 6.8" W x 9.4" H per battery.
• Dual-Battery Setup: The 2019 Kenworth T680, like most heavy-duty diesel trucks, utilizes a multi-battery setup, commonly three or four Group 31 batteries wired in parallel for a 12V system to deliver the necessary cranking power and reserve capacity.

Replacement Battery Options

Due to the specific needs of a heavy-duty truck like the Kenworth T680, replacing the batteries often involves selecting durable Group 31 options. While specific part numbers can vary by retailer and exact battery variant (e.g., standard, deep cycle, AGM), here are common series from popular brands:

• Interstate: MT31 (Flooded) or AGM-31 (AGM)
• Optima: Optima does not currently offer a direct Group 31 battery, as their focus is on automotive and light truck applications with different form factors.
• DieHard: DieHard Platinum Group 31 (AGM) - generally equivalent to Odyssey Group 31 offerings.
• Odyssey: PC2150 (AGM) or ODX-AGM31M (AGM)
• ACDelco: 31TLPF (Flooded) or 31AGM (AGM)

Important Note on Part Numbers

Battery part numbers are subject to change. Always verify the BCI group size, CCA, and physical dimensions with your supplier and compare against your truck's requirements before purchase. For heavy-duty applications, it's critical to replace all batteries in a multi-battery bank simultaneously to ensure balanced performance and longevity.

AGM vs. Flooded — Which Does This Vehicle Need?

The 2019 Kenworth T680 typically comes from the factory with flooded lead-acid Group 31 batteries. These are a cost-effective and proven solution for the demanding starting requirements of a heavy-duty diesel engine. However, AGM (Absorbent Glass Mat) batteries are an excellent upgrade and are becoming increasingly popular for several reasons:

• Durability: AGMs are more resistant to vibration, which is a significant factor in commercial trucking.
• Maintenance-Free: No need to check electrolyte levels, as they are sealed.
• Deeper Discharge Cycles: Better suited for powering accessories, APUs, and handling repeated deep discharges without significant capacity loss, which is common in trucks that sit idle with electronics running.
• Faster Recharging: AGMs generally accept a charge more efficiently.

If your T680 has an APU, extensive hotel loads, or operates in extreme conditions, upgrading to AGM batteries can provide superior performance and a longer lifespan, justifying the higher initial cost. If your truck is primarily used for driving with minimal accessory draw when parked, flooded batteries remain a viable and economical choice.

Post-Installation Relearn / Reset Procedure

For a 2019 Kenworth T680, replacing the batteries is generally straightforward, but there are a few considerations to ensure all systems function correctly:

1. Safety First: Always disconnect the negative terminals first and reconnect them last to prevent accidental shorts. Wear appropriate safety gear.
2. ECM Memory: While the primary engine control module (ECM) is designed to retain most of its critical data even with a prolonged power disconnect, some minor settings or learned parameters (like idle characteristics) might reset or require a short driving cycle to re-learn. You typically won't need a specialized "relearn" tool for battery replacement alone.
3. Radio/Infotainment: You may lose radio presets, clock settings, and potentially some personalized infotainment settings. These can be reprogrammed manually.
4. Diagnostic Trouble Codes (DTCs): Intermittent or "soft" DTCs related to low voltage might clear themselves after new batteries are installed and the truck is run. Hard codes or persistent issues will remain and require proper diagnosis.
5. Let it Run: After installing new batteries, start the truck and let it idle for 10-15 minutes. This allows the charging system to stabilize and any minor system "re-adjustments" to occur.

Unlike some passenger vehicles with complex battery monitoring systems that require specific registration, the 2019 Kenworth T680 typically does not require a formal "relearn" procedure for the battery itself.

Signs of a Failing Battery

Recognizing the signs of battery failure in your Kenworth T680 can prevent unexpected breakdowns:

• Slow Cranking: The most common sign. The engine turns over sluggishly, especially in cold weather.
• Dim Lights: Headlights or interior lights appear dim when the engine is off or cranking.
• Electrical Issues: Malfunctioning accessories, error messages on the dash, or intermittent power to electronics.
• Frequent Jumps: Needing to jump-start the truck often.
• Corrosion: Excessive corrosion around the battery terminals (though this can also indicate other charging system issues).
• Swollen Battery Case: A clear sign of internal damage, often due to overcharging or extreme heat.
• Battery Age: Heavy-duty truck batteries typically last 3-5 years, depending on usage and maintenance.

Given the multi-battery setup, a failure in one battery can impact the entire bank. It's best to test all batteries if you suspect an issue.

Common Battery Issues for This Generation

For the 2019 Kenworth T680 and similar heavy-duty trucks, certain battery issues are common:

• Vibration Damage: Constant road vibration can shorten the life of flooded batteries significantly. AGM batteries are more resilient.
• Parasitic Draw: Accessories, telematics, or even faulty components can slowly drain batteries when the truck is off, leading to premature failure if not addressed.
• APU/Hotel Load Cycling: Frequent deep discharges from powering APUs and cab amenities put a heavy strain on batteries. Using deep-cycle or AGM batteries helps mitigate this.
• Charging System Failures: A failing alternator or voltage regulator can either undercharge (leading to dead batteries) or overcharge (leading to battery damage, especially in flooded types).
• Corrosion and Poor Connections: Loose or corroded battery cables and terminals increase resistance, hindering proper charging and starting power.
• Uneven Battery Wear in Multi-Bank Systems: If one battery in a multi-battery setup starts to fail, it can drag down the performance and lifespan of the others. This is why replacing all batteries simultaneously is recommended.

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