Is it Possible to Run Your Caravan A/C on Battery and Solar Power?

One of the many questions caravanners have regarding their A/C unit is whether or not they can run it using battery power. The short answer is no because a typical caravan air conditioner requires a lot of electricity to start up. But that doesn’t mean it’s impossible as you will definitely need multiple batteries along with solar panels to offset your battery draw.

Let’s take a look at what you need to do in order to run your caravan A/C on battery and solar power.

How to run your caravan A/C on battery power

Most caravans today are equipped with a 15,000 BTU A/C unit that requires a minimum of 3,500 watts to start up and 1,500 watts to keep it running. At the very least, you’ll need a 4,000-watt DC to AC power inverter to transform your battery power into usable A/C electricity. Caravans usually don’t come equipped with an inverter that large as most of them have inverters that range from 1,000 to 2,000 watts only.

If you own a high-end RV, chances are it’s equipped with a fairly large inverter. Fifth-wheel trailers, class A motorhomes, and even class B vans sometimes have two to three air conditioning units which explain why they have large power inverters.

Many caravanners use solar panels and lithium batteries to power their DC electrical needs such as the water pump, fans, lights, power awning, and other light-duty electricals. This setup provides all the power you need to free camp comfortably for weeks. Some free campers choose to camp in a higher ground where the temperatures are lower so they can cut down on their need for air conditioning.

If a free camper requires AC electrical power, it’s usually for light-duty appliances like a television, blender, or even a C-PAP unit. These devices can be powered by a battery using a smaller power inverter of 500 to 1,000 watts. This assumes that they have an adequately-sized battery bank of about 200 to 300 AH, and a sufficient-sized solar panel that ranges from 400 to 800 watts.

When solar power is paired with a decent sized battery bank and a medium-sized power inverter, you can create an affordable setup to power up some of the creature comforts you’re looking for while free camping.

Let’s say you have three 100 AH (amp-hour) lithium-ion phosphate batteries and a 7,000-watt inverter, you can potentially run two 15,000 BTU A/C units for an hour, provided that you have around 1,500 watts of solar panels on the roof that will offset your power draw.

If that kind of setup will power the air conditioner for one hour, imagine how complex your setup should be to run the whole unit in 8 hours. In order to do this, you’ll need multiple batteries. A typical 12-volt battery cell that delivers 100 AH weighs around 23kg. You may need 16-20 of those batteries to keep two A/C units running for 8 hours which takes a sizable chunk off of your cargo capacity.

Why it’s impractical to run your caravan A/C off of batteries

A standard 12 volt, 100 AH lithium-ion phosphate battery usually costs around $1,000. With our previous example mentioned above, you’ll need to spend around $16,000-$20,000 on batteries alone just to keep your caravan A/C running for 8 hours.

Add in the expense of buying a 7,000+ watt power inverter which can set you back $2,000, and you’re looking at a highly impractical means of powering your A/C unit. You’ll also need to invest in 1,500-watt solar panels to replenish your batteries while the air conditioner is running. This will cost you around $1,500.00 to $2,000.00 depending on the type of panels you go for.

When you factor the costs of additional components (solar panel mounting hardware, transfer switch, a battery monitor,  etc.) you’re looking at a whopping $11,000 to $12,000 dollars of operating expenses just to run two air conditioning units in a day. And again, that’s assuming you’re under direct sunlight to be able to recharge your batteries.

While the thought of running your caravan A/C on batteries sounds exciting, it’s not the most sustainable method of doing so. This is what generators come in. Generators are capable of powering heavy-draw appliances like air conditioning units and microwave ovens. While generators are expensive and their operating costs are way up there, it’s the most sustainable way of powering all your appliances.

You don’t have to worry about having adequate sunlight or enough battery power to run your A/C unit which gives you peace of mind while free camping.