How to Replace Your RV Battery (DIY Step-by-Step Guide)

Replacing an RV battery is easier than you think — even for beginners. In this guide, you’ll learn exactly how to remove your old battery and install a new one safely and correctly.

Tools & Supplies You’ll Need

• 🔧 Wrenches or socket set (for battery terminals)
• 🧤 Gloves and safety glasses
• 🧼 Baking soda & brush (for corrosion)
• 📏 Measuring tape (if upgrading battery size)
• 🔋 Your replacement battery (AGM, lithium, etc.)

Step 1: Turn Off All Power Sources

Before doing anything, disconnect your RV from shore power and turn off all breakers. If you have a battery disconnect switch, flip it off.

Step 2: Locate and Access the Battery Compartment

Most RV house batteries are located in a front compartment, step box, or near the chassis rail. Make sure the area is well-ventilated if using lead-acid batteries.

Step 3: Disconnect the Battery

Start by disconnecting the negative (–) terminal first, then the positive (+). This prevents sparks or shorts.

Step 4: Clean the Terminals

Check cables and battery tray for corrosion. Use a mix of baking soda and water with a wire brush to clean terminals and mounting surfaces.

Step 5: Install the New Battery

• Place the new battery in the tray and secure it properly
• Connect the positive cable first
• Then connect the negative cable
• If using lithium, make sure it’s compatible with your charger

Step 6: Test the System

Restore shore power or solar input, then check your battery voltage and make sure your 12V system is functioning. Use a multimeter or onboard monitor to confirm it’s charging correctly.

Bonus Tips

• 📌 Use dielectric grease on terminals to reduce future corrosion
• 🔌 If switching to lithium, you may need a new converter or DC-DC charger
• 🔍 Double check wiring polarity — wrong connections can damage electronics

When Should You Replace an RV Battery?

Common signs your battery is done:

• Voltage drops quickly after charging
• Battery swells or leaks
• Appliances cut out randomly
• Battery older than 4–7 years (AGM), or 10+ years (Lithium)

Related Guides

• How Long Do RV Batteries Last?
• RV Battery Won’t Charge? Here’s Why
• Best Lithium Batteries for RVs
• Charging Guide – AGM, Gel, Lithium

Replacing your RV battery yourself is a simple, satisfying upgrade. Whether you’re switching to lithium or refreshing an old AGM, this DIY will keep your rig powered up and ready for the road.