2015 Ram ProMaster Battery Size, CCA & Group Specifications

As an ASE-certified master technician, I’ve worked on countless commercial vans. The 2015 Ram ProMaster is a heavy-duty workhorse, and because of its extensive electrical demands—from cargo lighting to power inverters—it requires a robust battery system to keep your business on the road. Interestingly, the battery in the ProMaster isn't under the hood; it’s located under the driver’s side floorboard.

If you are dealing with a dead battery on your 3.6L Pentastar V6 or 3.0L EcoDiesel, here is everything you need to know about your 2015 Ram ProMaster’s battery specifications.

Quick answer: 2015 Ram ProMaster Battery Specs

• BCI Group Size: Group H7 (also known as 94R). Some 3.0L EcoDiesel models with high electrical outputs may utilize a larger Group H8 (49) or a dual-battery setup depending on the upfitter package.
• Cold Cranking Amps (CCA): 730 to 800 CCA is standard. Diesels should aim for 800+ CCA.
• Reserve Capacity (RC): 130 to 140 minutes minimum.
• AGM vs Flooded: The vehicle originally came with a high-quality flooded battery, but upgrading to an Absorbent Glass Mat (AGM) is highly recommended for commercial use.
• Terminal Layout: Standard Top Post (Positive on the Right).
• Physical Dimensions (H7/94R): Approximately 12.4 inches long, 6.9 inches wide, and 7.5 inches high.
• Dual-Battery Setup: Not standard on base models, but common on cutaway or chassis cab models modified for RVs or ambulances. These typically run two batteries in parallel under the floor or in an auxiliary battery box.

Replacement battery options

If you are replacing the battery in your 2015 ProMaster, it pays to invest in a premium unit. Because of the location under the floor, changing it is a bit of a chore, so you want a battery that will last. Here are some of the most reliable options on the market:

• Interstate Batteries MTX-94R/H7: A premium AGM battery offering 800 CCA and excellent deep-cycle capabilities, perfect for delivery drivers with frequent engine starts.
• DieHard Platinum AGM Battery, Group Size H7: (Part No. H7-AGM) Provides 850 CCA and a 140-minute reserve capacity. Highly vibration-resistant.
• Optima Batteries YellowTop DH7: A true dual-purpose deep-cycle and starting AGM battery. Exceptional for vans with aftermarket power inverters or cargo lifts.
• ACDelco Gold 94RAGM: A reliable OEM-style AGM replacement that offers 850 CCA and great longevity.

AGM vs flooded — which does this vehicle need?

From the factory, many standard 2015 ProMasters rolled off the line with standard flooded lead-acid batteries. However, as an ASE technician, I strongly advise upgrading to an AGM (Absorbent Glass Mat) battery.

Commercial vans undergo brutal drive cycles. Frequent stopping and starting, heavy vibration from carrying loads over rough roads, and high electrical draws from auxiliary equipment all take a toll. AGM batteries handle deep discharges better, recharge faster, and are vastly more vibration-resistant than flooded batteries. Furthermore, since the battery is mounted inside the cabin (under the floor), an AGM battery offers peace of mind because it is completely sealed and spill-proof.

Post-installation relearn / reset procedure

Unlike some complex European vehicles of this era, the 2015 Ram ProMaster does not have an overly complicated Battery Management System (BMS) that requires a scan tool for a battery registration. However, after disconnecting the battery, you will need to perform a few simple resets:

1. Clock and Radio Presets: You will need to reset your clock and potentially your Uconnect radio presets.
2. Steering Angle Sensor Relearn: Start the engine, turn the steering wheel all the way to the left lock, then all the way to the right lock, and back to center. This clears the ESP/Traction Control warning lights that trigger after a power loss.
3. Power Windows: If your one-touch auto-up window feature stops working, roll the window all the way down and hold the switch for 2 seconds. Then, roll it all the way up and hold the switch for 2 seconds.

Signs of a failing battery

Don't wait until you're stranded at a job site. Watch for these warning signs:

• Slow Engine Crank: The 3.6L V6 and the 3.0L diesel require substantial cranking amps. If it sounds sluggish, the battery is dying.
• Dimming Lights at Idle: Headlights or interior cargo lights dimming when the van is idling indicates a weak battery or failing alternator.
• Electronic Gremlins: The ProMaster's CAN-bus system is very sensitive to voltage drops. A dying battery will often trigger random warning lights (ABS, Airbag, Check Engine) that disappear once the van is running.
• Need for Jump Starts: If you have to jump-start the van after leaving a cargo light on for just a few minutes, the battery’s reserve capacity is depleted.

Common battery issues for this generation

The biggest issue for the 2015 Ram ProMaster isn't the battery itself, but its location. Being bolted beneath the driver’s side floorboard means it is completely out of sight. Fleet drivers rarely inspect the battery terminals for corrosion because doing so requires removing a floor panel. I frequently see ProMasters towed into the shop for "no start" conditions, only to find that the battery is perfectly fine, but the terminals are completely covered in white, fuzzy corrosion. Make it a habit to pull that floor panel every 15,000 miles to clean and tighten your battery connections.

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