2025 Jeep Gladiator Battery Size & Replacement Guide

As an ASE-certified master technician, I see a lot of modern Jeeps roll into the bay with electrical gremlins that ultimately trace back to the battery. The 2025 Jeep Gladiator is an incredible midsize truck, but its advanced electronics, infotainment systems, and Engine Stop-Start (ESS) feature place a massive demand on its electrical system. If your Gladiator is struggling to turn over or throwing weird dashboard warnings, it is probably time for a battery replacement.

Here is everything you need to know about the battery specifications, group sizes, and replacement procedures for your 2025 Jeep Gladiator.

Quick answer

• BCI Group Size: Group H6 (48) is standard for most trims. Models equipped with the Max Tow Package, heavy-duty electrical groups, or the EcoDiesel (if applicable to your specific trim) may use the larger Group H7 (94R).
• Cold Cranking Amps (CCA): Minimum 700 CCA for the H6; up to 800+ CCA for the H7.
• Reserve Capacity (RC): Typically 120 to 140 minutes.
• AGM vs. Flooded Requirement: AGM (Absorbent Glass Mat) is strictly required. Standard flooded batteries cannot handle the ESS system or the high electrical loads of this truck.
• Terminal Layout: Standard SAE posts, Right Positive (RHP).
• Physical Dimensions: H6 (10.94" L x 6.93" W x 7.5" H); H7 (12.44" L x 6.93" W x 7.5" H).
• Dual-Battery Setup: Yes. Gladiators equipped with the ESS system feature a dual-battery setup. There is the main primary battery (H6/H7) and a much smaller auxiliary battery (often an AUX14) hidden underneath the main battery box or PDC (Power Distribution Center) that strictly manages the start/stop events.

Replacement battery options

When replacing the main battery in your Gladiator, you want to stick to premium AGM options. Here are some of the most reliable and popular replacement options:

• Interstate Batteries: MTX-48/H6 or MTX-94R/H7 (Premium AGM)
• DieHard: Platinum AGM Battery, Group Size H6 or H7
• Optima Batteries: DH6 YellowTop (Dual-purpose deep cycle and starting AGM)
• Odyssey: ODP-AGM48 H6 L3 or ODP-AGM94R H7 L4 (Extreme series for high-demand winching/off-roading)
• ACDelco: Gold 48AGM or 94RAGM (Professional series)

Tech tip: If your main battery is dead, highly consider replacing the auxiliary battery at the same time. A dead aux battery will quickly drag down and kill a brand new main battery.

AGM vs flooded — which does this vehicle need?

The 2025 Jeep Gladiator absolutely requires an AGM battery. DO NOT install a traditional flooded lead-acid battery. The Gladiator uses an Intelligent Battery Sensor (IBS) and an aggressive charging profile designed specifically for the charge acceptance rate of an AGM battery. Furthermore, standard flooded batteries degrade rapidly under the continuous cycling of the Engine Stop-Start system. Installing a flooded battery will result in a severely shortened lifespan and likely void any electrical warranties.

Post-installation relearn / reset procedure

Unlike some European vehicles that require a scan tool to code a new battery, the Jeep Gladiator is a bit more forgiving, but there is still a procedure to ensure the Intelligent Battery Sensor (IBS) recognizes the new unit:

1. Disconnect the IBS: When swapping the battery, be careful with the small IBS sensor attached to the negative terminal.
2. Install and Connect: Install the new battery, tightening the positive terminal first, followed by the negative terminal with the IBS.
3. The Sleep Cycle: The vehicle's Body Control Module (BCM) needs to learn the new battery's state of charge. To do this, simply lock the truck and let it sit entirely undisturbed (no key fobs nearby, no opening doors) for at least 8 hours (usually overnight).
4. ESS Reset: You may notice the Auto Start-Stop system says "Not Ready" on the dashboard for the first few days of driving. This is completely normal; the system requires a few drive cycles to verify the new battery's stability before re-engaging.

Signs of a failing battery

Modern Jeeps are incredibly sensitive to voltage drops. Keep an eye out for these symptoms:

• Auto Start-Stop (ESS) stops working and displays a "Start/Stop Unavailable" message.
• Slow or hesitant engine cranking, especially on cold mornings.
• Random "Check Engine" lights or traction control warnings upon startup that disappear after driving.
• The infotainment touchscreen rebooting or lagging on startup.

Common battery issues for this generation

The most notorious issue with the JT Gladiator (and its JL Wrangler sibling) is the dual-battery ESS system. The small auxiliary battery is buried under the main battery and fuse box. Because the two batteries are wired in parallel during vehicle operation, if the auxiliary battery shorts out or drops a cell, it will parasitically drain the main H6/H7 battery.

Many owners falsely assume their main battery is defective, replace it, and then find the new battery dead a week later. As a master tech, my advice is simple: test both batteries independently. If one is bad, it is usually best practice to replace both simultaneously to prevent the old one from ruining the new one.

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