2020 Jeep Gladiator: Finding The Auxiliary Battery

Oct 23, 2025 by Jhon Lennon 51 views

Hey there, Gladiator fans! If you're scratching your head trying to locate the auxiliary battery in your 2020 Jeep Gladiator, you're definitely not alone. It can be a bit tricky, but don't worry, we've got you covered. This guide will walk you through everything you need to know about finding and understanding your Gladiator's auxiliary battery.

Why Does Your Gladiator Need an Auxiliary Battery?

First off, let's talk about why your Gladiator might even have an auxiliary battery in the first place. Modern vehicles, especially those designed for off-roading and overlanding like the Gladiator, often come equipped with dual battery systems to handle the increased electrical demands. This is especially true for Gladiators equipped with the cold weather package. Think about it: you've got your standard vehicle functions, plus all the extra accessories like winches, aftermarket lights, refrigerators, and other power-hungry gadgets.

An auxiliary battery provides a separate power source to run these accessories without draining your main starting battery. This ensures that you won't be stranded with a dead battery when you're miles away from civilization. Having that extra power source gives you peace of mind and allows you to enjoy your adventures to the fullest.

The auxiliary battery system is designed to:

Power additional accessories: Run lights, winches, fridges, and other aftermarket equipment.
Protect the main battery: Prevent draining the main battery, ensuring you can always start your vehicle.
Provide backup power: Offer a reserve power source in case the main battery fails.
Enhance overall system performance: Distribute the electrical load for optimal system efficiency.

Without an auxiliary battery, running a bunch of accessories could quickly deplete your main battery, leaving you in a lurch. Trust me, you don't want to find yourself in that situation when you're out on the trail. So, understanding the auxiliary battery system and knowing where it is located is super important for any Gladiator owner.

Locating the Auxiliary Battery: Where to Look

Alright, let's get down to the nitty-gritty. Where is this elusive auxiliary battery hiding in your 2020 Jeep Gladiator? In most Gladiators, especially those with the optional cold weather package, the auxiliary battery is typically located under the rear seat on the driver's side.

Here’s a step-by-step guide to finding it:

Prepare your Gladiator: Park your Gladiator on a level surface and turn off the engine. Make sure the parking brake is engaged for safety.
Access the rear seat: Open the rear driver's side door to access the rear seat area. You might want to clear out any items that are on the floor or seat to give yourself more room to work.
Lift the rear seat: The rear seat cushion usually flips up to reveal the storage area underneath. Locate the release mechanism, which is often a strap or lever located near the front edge of the seat. Pull the strap or lever to release the seat cushion and lift it up. In some models, you might need to push the seat backward slightly while lifting to disengage it from the retaining clips.
Locate the battery: Once the seat is flipped up, you should see a covered compartment. This compartment houses the auxiliary battery. It's usually a black plastic box with a cover secured by screws or clips.
Inspect the battery: Carefully inspect the battery. Note the condition of the terminals and connections. Look for any signs of corrosion, damage, or loose wires. If you notice any issues, address them promptly to ensure the battery functions correctly.

Important Considerations:

Not all Gladiators have an auxiliary battery. It's usually an optional feature or included in specific packages like the cold weather package. If you don't see a battery under the rear seat, your Gladiator might not be equipped with one.
Check your owner's manual. Your owner's manual will have specific information about your Gladiator's battery system, including the location of the auxiliary battery (if equipped) and maintenance procedures.
Safety first! When working with any electrical components, always disconnect the negative terminal first to prevent short circuits. If you're not comfortable working with electrical systems, it's best to have a qualified mechanic handle the job.

Understanding the Auxiliary Battery System

Now that you've located the auxiliary battery, let's dive a little deeper into how the system works. The auxiliary battery is typically connected to the main battery through an isolator or battery management system. This system ensures that the auxiliary battery is charged by the alternator when the engine is running but prevents it from draining the main battery when the engine is off.

Here’s a breakdown of the key components:

Auxiliary Battery: Provides a secondary power source for accessories.
Main Battery: Powers the vehicle's essential functions like starting the engine.
Battery Isolator/Management System: Regulates the charging and discharging of both batteries.
Wiring and Connections: Connects the batteries, isolator, and accessories.

How the System Works:

Charging: When the engine is running, the alternator charges both the main and auxiliary batteries. The battery isolator ensures that the auxiliary battery receives a charge without drawing power from the main battery.
Discharging: When the engine is off, accessories are powered by the auxiliary battery, preventing the main battery from being drained. The battery isolator prevents the auxiliary battery from powering the vehicle's essential functions.
Isolation: The battery isolator ensures that the two batteries are isolated from each other when the engine is off. This prevents a dead main battery if you accidentally leave accessories running for an extended period.

Understanding how these components work together can help you troubleshoot any issues you might encounter with your Gladiator's electrical system. For example, if your accessories are not working, the issue could be a blown fuse, a faulty connection, or a problem with the auxiliary battery itself. Checking these components can help you identify and resolve the problem.

Maintaining Your Auxiliary Battery

To keep your auxiliary battery in tip-top shape, it's important to perform regular maintenance. A little bit of preventative care can go a long way in extending the life of your battery and ensuring reliable performance.

Here are some essential maintenance tips:

Check the Terminals: Inspect the battery terminals for corrosion. Clean them with a wire brush and baking soda solution if necessary. Apply a thin coat of dielectric grease to prevent future corrosion.
Test the Battery Voltage: Use a multimeter to check the battery voltage. A fully charged auxiliary battery should read around 12.6 volts. If the voltage is significantly lower, the battery might need to be charged or replaced.
Ensure Proper Connections: Check all wiring connections to ensure they are secure and free from corrosion. Loose or corroded connections can cause voltage drops and affect the performance of your accessories.
Monitor Battery Health: Keep an eye on the battery's overall health. If you notice any signs of weakness, such as dimming lights or slow accessory performance, have the battery tested by a professional.
Proper Storage: If you're storing your Gladiator for an extended period, disconnect the auxiliary battery to prevent it from draining. Store the battery in a cool, dry place.

When to Replace Your Auxiliary Battery:

Like any battery, your auxiliary battery will eventually need to be replaced. The lifespan of an auxiliary battery can vary depending on usage, climate, and maintenance. However, a well-maintained auxiliary battery can last for several years.

Here are some signs that it might be time to replace your auxiliary battery:

Difficulty Starting Accessories: If your accessories are slow to start or don't work at all, it could be a sign that the auxiliary battery is weak.
Low Voltage Readings: If the battery voltage consistently reads below 12 volts, it's likely time for a replacement.
Visible Damage: If the battery case is cracked or leaking, it needs to be replaced immediately.
Age: If the battery is more than three to five years old, it might be nearing the end of its lifespan.

Upgrading Your Auxiliary Battery System

If you're a serious off-roader or overlander, you might consider upgrading your Gladiator's auxiliary battery system. There are several aftermarket options available that offer increased capacity and performance.

Here are some popular upgrades:

Higher Capacity Battery: Upgrade to a larger capacity auxiliary battery for longer run times and increased power output.
Dual Battery Systems: Install a dual battery system with two auxiliary batteries for maximum power and redundancy.
Lithium-Ion Batteries: Consider a lithium-ion auxiliary battery for superior performance, lighter weight, and longer lifespan.
Advanced Battery Management Systems: Upgrade to a more advanced battery management system with features like remote monitoring and automatic equalization.

Benefits of Upgrading:

Increased Power: Enjoy more power for your accessories and longer run times.
Improved Reliability: Reduce the risk of a dead battery in remote locations.
Enhanced Performance: Experience faster accessory startup and more consistent power output.
Greater Flexibility: Run more accessories simultaneously without worrying about draining the battery.

Before upgrading your auxiliary battery system, it's important to consider your specific needs and budget. Research different options and choose a system that's compatible with your Gladiator and your intended use. It's also a good idea to consult with a qualified mechanic or electrical specialist to ensure that the installation is done correctly and safely.

Final Thoughts

So there you have it – a comprehensive guide to locating and understanding the auxiliary battery in your 2020 Jeep Gladiator! Whether you're a seasoned off-roader or just getting started, knowing how your Gladiator's electrical system works is essential for enjoying your adventures to the fullest. By following these tips and performing regular maintenance, you can keep your auxiliary battery in top shape and ensure that you always have the power you need, when you need it.

Happy trails, and may your Gladiator always have a full charge!