2017 Freightliner M2 106 Battery Size & Group

Quick answer

• BCI Group Size: Group 31 (typically three or four batteries)
• CCA Rating: 925-1150 CCA per battery (for optimal starting in all conditions)
• Reserve Capacity: 180-200 minutes per battery
• AGM vs. Flooded: Flooded lead-acid is standard, but AGM is an excellent upgrade for increased durability and longer life.
• Terminal Layout: Typically SAE posts with threaded terminals for heavy-duty connections.
• Physical Dimensions (Group 31): Approximately 13" L x 6.8" W x 9.4" H
• Dual-Battery Setup: The 2017 Freightliner M2 106, particularly with diesel engines, uses a multi-battery setup, commonly three or four Group 31 batteries wired in parallel for 12V operation and increased cranking power.

Replacement battery options

When it's time to replace the batteries in your 2017 Freightliner M2 106, quality and reliability are key. Here are some popular options:

• Interstate:
  • 31-MHD (Flooded Heavy Duty)
  • 31-AGM7 (AGM Heavy Duty)
• Optima:
  • (Optima does not typically make a Group 31 battery suitable for this application. Consider other brands for Group 31.)
• DieHard:
  • 31-PLT (Platinum AGM - if available in Group 31)
  • 31-M (Commercial Flooded - if available in Group 31)
• Odyssey:
  • 31-PC2150 (AGM - specifically designed for heavy-duty commercial applications)
• ACDelco:
  • 31-700 (Professional Flooded)
  • 31-AGM (Professional AGM)

AGM vs. flooded — which does this vehicle need?

The 2017 Freightliner M2 106 typically comes equipped with flooded lead-acid batteries from the factory. These are a cost-effective and reliable choice, proven to perform well in most operating conditions. However, upgrading to AGM (Absorbent Glass Mat) batteries offers several advantages:

• Durability: AGM batteries are more resistant to vibration, which is a significant factor in commercial truck applications. They also handle deep discharges better.
• Maintenance-Free: Unlike flooded batteries, AGMs are sealed and do not require watering, making them truly maintenance-free.
• Performance: AGMs often offer higher cold cranking amps and a lower self-discharge rate, meaning they hold a charge longer when the truck is not in use.
• Safety: They are spill-proof, which is a benefit in case of an accident or tip-over.

While AGM batteries have a higher upfront cost, their extended lifespan and enhanced performance can make them a worthwhile investment for the demanding life of a Freightliner M2 106.

Post-installation relearn / reset procedure

After replacing the batteries in your 2017 Freightliner M2 106, a few steps are important to ensure all systems reset correctly:

1. Verify Connections: Double-check all battery terminals to ensure they are clean, tight, and correctly oriented. Loose connections can cause intermittent electrical issues.
2. Initial Start-up: Start the engine and let it idle for 5-10 minutes. This allows the engine control unit (ECU) and other modules to re-initialize and perform basic system checks.
3. Check for Warning Lights: Observe the dashboard for any persistent warning lights (e.g., Check Engine, ABS, etc.). Most temporary lights related to power loss should extinguish after a short drive cycle.
4. Window Resets (if applicable): Some Freightliner models may require a window reset. To do this, lower each power window completely, then raise it completely and hold the button for an additional 2-3 seconds at the top. Repeat for all power windows.
5. Radio/Infotainment System: You may need to re-enter radio presets or navigation settings. If equipped, the infotainment system might require a full power cycle or a factory reset if it malfunctions.
6. Drive Cycle: A short drive cycle (15-30 minutes) under various conditions (city, highway) can help the vehicle's computer system recalibrate and confirm all emissions and transmission parameters.

For any persistent issues or specific module resets, consulting the vehicle's owner's manual or a Freightliner service manual is recommended.

Signs of a failing battery

Given that the M2 106 uses multiple batteries, signs of failure might not be as immediate as in a single-battery vehicle. However, common indicators include:

• Slow Cranking: The engine turns over sluggishly, especially in cold weather.
• Dim Lights: Headlights or interior lights appear dim when the engine is off.
• Electrical Gremlins: Intermittent issues with accessories like the radio, windows, or dashboard lights.
• Corrosion: Excessive corrosion around the battery terminals (though this can also indicate loose connections).
• Swollen Battery Case: Bulging or cracking of the battery case, often a sign of overcharging or internal damage.
• Frequent Jump Starts: Needing to jump-start the truck often.
• "Check Battery" Light: Or similar warning on the dashboard.

Common battery issues for this generation

The 2017 Freightliner M2 106, like many heavy-duty trucks, can experience particular battery-related challenges:

• Vibration Damage: Constant vibration from road conditions and engine operation can damage internal battery plates and connections. This is where AGM batteries offer a significant advantage.
• Parasitic Draw: Aftermarket accessories or electrical issues can lead to a parasitic draw, slowly draining batteries even when the truck is off. Identifying and resolving these draws is crucial for battery longevity.
• Alternator/Charging System Issues: A faulty alternator or voltage regulator can either undercharge (leading to weak batteries) or overcharge (leading to premature battery failure and swelling) the battery bank.
• Improper Maintenance: For flooded batteries, neglecting to check and top off electrolyte levels can lead to premature failure. Keeping terminals clean and tight is vital for all battery types.
• Cold Weather Performance: Diesel engines require significant cranking power, making battery health critical in cold climates. Older or weaker batteries will struggle to start the truck in low temperatures.

Find a trusted shop on Repairius.