2025 Jeep Wrangler Battery Size & Replacement Guide

As an ASE-certified master technician, I’ve seen my fair share of late-model Jeeps in the bay, and the JL-generation Wrangler has one of the most talked-about battery systems on the market today. If you're looking to replace the battery in your 2025 Jeep Wrangler, you need to know exactly what you’re dealing with—especially since most non-hybrid models utilize a dual-battery system to support the Engine Stop/Start (ESS) feature.

Here is your comprehensive guide to the battery requirements for the 2025 Jeep Wrangler.

Quick answer: 2025 Jeep Wrangler Battery Specs

• BCI Group Size: Group H6 (48) is standard for most 2.0L and 3.6L models. Some heavily optioned trims or the Rubicon 392 (6.4L) may step up to a Group H7 (94R). Auxiliary Battery (ESS models): Group 400 (AUX14). (Note: The 4xe plug-in hybrid has a completely different high-voltage architecture and a standard 12V AGM).
• Cold Cranking Amps (CCA): 650 to 800 CCA for the main battery, depending on engine and factory options. 200 CCA for the ESS auxiliary battery.
• Reserve Capacity (RC): 120–140 minutes for the main H6 battery.
• AGM vs. Flooded: Absorbent Glass Mat (AGM) is strictly required due to the ESS system and heavy electrical loads.
• Terminal Layout: Standard SAE top posts, Right Positive (Standard layout).
• Physical Dimensions (H6/48): Approx. 11.0" L x 6.9" W x 7.5" H.
• Dual-Battery Setup: Yes. Non-4xe models with ESS use a smaller auxiliary battery tucked beneath the main battery or main fuse box to keep accessories running while the engine shuts off at stoplights.

Replacement battery options

When replacing a Wrangler battery, quality matters. Because the Jeep is subjected to off-road vibrations and high electrical demands (winches, lights, ESS), I always recommend premium AGM replacements. Here are top choices for the Group H6 main battery:

1. Odyssey Performance Series AGM (Part # ODP-AGM48 H6 L3): Exceptional vibration resistance and deep-cycling capabilities. Perfect for off-roading.
2. DieHard Platinum AGM (Group Size H6): A highly reliable, readily available option that meets or exceeds OEM specifications.
3. Optima YellowTop (Part # DH6): A premium dual-purpose battery that offers excellent deep-cycling for aftermarket accessories.
4. Interstate MTZ AGM (Part # MTZ-48/H6): Known for longevity and strong warranty support across the country.
5. ACDelco Gold AGM (Part # 48AGM): An excellent OEM-style replacement.

For the ESS Auxiliary Battery, the ACDelco AUX14 or equivalent Group 400 AGM is the standard replacement.

AGM vs flooded — which does this vehicle need?

Your 2025 Jeep Wrangler requires an AGM (Absorbent Glass Mat) battery. Do not downgrade to a traditional flooded lead-acid battery. The Wrangler's Intelligent Battery Sensor (IBS) and charging system are calibrated specifically for AGM charge acceptance rates. Furthermore, the constant cycling of the Engine Stop/Start (ESS) system will destroy a standard flooded battery in a matter of months. AGM batteries also offer spill-proof designs and superior vibration resistance, which is critical for off-road driving.

Post-installation relearn / reset procedure

When you disconnect the battery on a JL-generation Wrangler, several modules lose their memory. Follow these steps after installing the new battery:

1. IBS Relearn: The Intelligent Battery Sensor needs to learn the new battery's state of charge. This generally happens automatically after the vehicle sits undisturbed (doors locked, key fob far away) for about 4 to 8 hours.
2. Steering Angle Sensor Calibration: 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 the center. This clears traction control and ESC warning lights.
3. Window Indexing: Roll the front windows all the way down and hold the switch for 2 seconds. Roll them all the way up and hold for 2 seconds. This resets the auto-up/down feature.

Signs of a failing battery

• ESS System Unavailable: This is usually the very first sign. You will get a message on your dash saying "Stop/Start Unavailable - Battery Charging" or "Service ESS."
• Slow Engine Crank: The engine turns over sluggishly, especially on cold mornings.
• Random Electrical Gremlins: The Uconnect infotainment screen rebooting randomly, flickering dash lights, or weird transmission shifting behavior.
• Warning Lights: The red battery icon or check engine light may illuminate.

Common battery issues for this generation

The dual-battery ESS system is notorious among JL Wrangler owners. The biggest issue is that the small auxiliary battery and the main battery are linked in parallel. When the smaller auxiliary battery begins to fail (which usually happens around the 3-year mark), it acts as a parasitic draw on the main battery. It will literally drain the life out of your brand-new main battery if not caught in time.

As a master tech, my advice is simple: When one battery fails, replace both of them. Replacing just the main battery while leaving a degraded auxiliary battery in the circuit guarantees you'll be buying another main battery very soon.

Need help wrestling with the dual-battery setup or clearing codes? Find a trusted shop on Repairius.