Running 3 A/Cs on Battery Power?! | The Ultimate Off-Grid RV Build

Meet Li-berty, the Big Beard Battery rolling showroom — proof that you can run multiple A/Cs, cook dinner, and live fully off-grid on pure battery power.

When we set out to build the Big Beard Battery rolling showroom, nicknamed Liberty, people said it couldn’t be done. They said no RV could run three air conditioners off battery power—and certainly not do it with 6,700 watts of rooftop solar. But at Big Beard Battery, we don’t listen to limits. We build systems that redefine what’s possible for full-time RVers, off-grid adventurers, and luxury fifth-wheel owners who refuse to compromise comfort for freedom.

This system, housed in a Luxe 48-foot FB, is more than a showpiece. It’s proof that advanced lithium power and precision solar design can deliver true energy independence—without exceeding height restrictions or sacrificing performance.

The Heart of the System: 6,700 Watts of Solar Power

Mounted flush and aerodynamically on the roof, Liberty’s 6,700W solar array sits perfectly below DOT limits at 13'4". The system uses a mix of Victron Energy components for unmatched reliability and data control.

• 10 high-efficiency solar panels feed into multiple solar controllers for optimal energy capture.

• Five total charge controllers, including a 250V/100A charger, manage power distribution from both rooftop and deployable solar arrays—pushing the system’s potential close to 9,000 watts of solar input.

With that much solar energy available, the batteries stay charged even on cloudy days, and generator use becomes nearly obsolete.

Powering the Impossible: 8,000 Continuous Watts of AC Output

To keep everything running, the system is built on two 24V 5,000VA (4,000W) inverters, configured to provide 8,000 watts of continuous power.

That’s enough to run:

• Three RV air conditioners

• An Instant Pot or microwave

• All lights, refrigerators, and outlets—simultaneously

A custom auto-transformer load balancer ensures each inverter shares the workload evenly. So even when one side of the coach demands more power (like multiple A/Cs), the system automatically evens the load across both inverters for maximum efficiency and reliability.

Five Massive 24V 300Ah Batteries = True Energy Independence

At the core of every Big Beard Battery system is storage. This rig features five 24V 300Ah lithium batteries, giving enough capacity to run two air conditioners all night long—no shore power needed.

Our philosophy is simple:

“You shouldn’t have to change how you live just because the sun went down.”

By morning, solar takes over seamlessly, recharging the system while the A/Cs keep the coach cool and comfortable.

Smarter Monitoring with Victron & Ruuvi Integration

The entire system is tied into a Victron Cerbo GX with a 7-inch touchscreen, giving full control and visibility over solar input, inverter output, battery voltage, and temperature sensors. Using Ruuvi Tags, we track temperature throughout the rig—from the refrigerator to inverter bays—so nothing runs out of spec.

And with auto generator start capability and remote access via the Victron app, this system can manage itself anywhere in the country. Whether you’re in a remote desert or boondocking deep in the woods, Liberty operates like it’s plugged into full-time shore power.

Designed, Built, and Tested by Big Beard Battery

The Liberty project proves one thing—off-grid luxury living is possible. It’s not just about batteries or solar panels. It’s about building complete systems designed to perform under real-world conditions.

Big Beard Battery specializes in:

• Custom lithium battery systems for RVs, vans, and off-grid homes

• Professional solar design and installation

• DIY solar kits and nationwide certified installer network

Whether you want to add more solar to your existing system or build a powerhouse like Liberty, Team Big Beard Battery can help you achieve it.

Ready to Build Your Own Off-Grid Powerhouse?

If you’re ready to experience true energy freedom—where you can run your entire RV without ever plugging in—let’s talk.