Here is a real-world test I ran using solar power to run air conditioning in my 18-foot RV. I’m using an LG dual inverter window A/C unit, and everything is powered by solar panels and LiFePO4 batteries. If you're thinking of doing something similar, keep in mind that performance really depends on a few key factors: the type and efficiency of your A/C unit, how many people are inside the RV, the outdoor temperature, and the size of the RV itself. All of these can make a big difference in how long your battery and solar setup will last.
Let me break down my experience.
Scenario 1: Just Me in the RV
I have an 18-foot aluminum-sided RV, and when I’m traveling alone on warm days—around 85°F—I use a 6,000 BTU LG dual inverter window A/C unit. These units are known for their high efficiency and low power draw, which makes them ideal for solar setups. My power system for this solo setup includes 500 watts of solar panels and 300Ah of LiFePO4 battery storage. This gives me enough energy to run the air conditioner for about 4 to 5 days in a row, as long as I have clear, sunny skies. If it’s cloudy or overcast, I can still run the A/C for about a day and a half before the batteries need to be recharged.
Scenario 2: Family on Board
Now, things change quite a bit when I have the whole family with me—that’s two adults, two kids, and a dog. As you’d expect, the extra body heat in a small space like an RV makes a big difference in how hard the air conditioner has to work. To handle the increased cooling demand, I upgraded my setup to 700 watts of solar and 600Ah of battery capacity. I’m still using the same A/C unit and the same 18-foot travel trailer, but the larger solar and battery bank helps maintain similar performance even with the added heat load. With this upgraded system, we can still enjoy several days of cooling, assuming the sun is shining.
In both the solo and family setups, I set the thermostat on the A/C to around 82°F during the hottest part of the day, from about 11 AM to 5 PM. I’ve found that this setting is a good balance—it keeps the RV from overheating without overloading the system. Plus, we’re usually outside during those hours anyway, so we don’t need the A/C blasting full force. This strategy helps stretch the battery life and allows the solar panels to keep up.
Bonus: It’s More Than Just Cooling
Even with the A/C running, we can charge our tablets, watch TV, and do most of our normal daily stuff—day and night—without any issues.
If you're looking into solar-powered A/C for your RV, I hope this gives you a good starting point. With the right gear and some planning, staying cool off-grid really is possible—even in summer heat.