You will need at least 1,800 watts of solar panels to run your RV air conditioner. This is assuming you are considering using 12 volt RV grade panels. This is also assuming, of course, you have a lot of battery power too. We suggest a battery bank of 800 amp hours. Most boondockers have between 200 to 400 amp hour battery banks. But, if you want to run that air conditioning unit for a minimum of four hours, perhaps up to eight hours, and still be able to run all of your other 110 volt and 12 volt components, you’re going to need LOTS of power.
How Many Solar Panels Do I Need to Run My RV AC?
If you want to run your RV air conditioner on solar and battery, remember that a typical RV air conditioning unit outputs 15,000 BTUs of cooling power. These AC units generally require about 3,500 watts of power just to start up, and then about 1,500 watts just to keep running. AC units demand so much electricity, that nearly all RVs are incapable of running them off of their factory battery & solar configurations.
The BoonDoctor, a mobile RV technician, installs Tesla Model S car batteries into RVs, usually a set of two, specifically for the purpose of running air conditioning units off of solar & battery. Each Tesla module produces about 200 to 220 amp hours of power, but at 24 volts. This is equivalent to four 12 volt, 100 amp hour lithium batteries (think Battleborn, Relion, et al). So, two Tesla Model S batteries, is equivalent to about eight or nine 12 volt lithium batteries.
BoonDoctor will mount 1,400 watts of “residential grade” solar panels on the roof. These are 24 volt panels, as opposed to typical 12 volt RV panels. These residential panels also run at about 21 to 22% efficiency, as opposed to the 17 to 18% efficiency of RV panels.
So, given the higher output of Tesla Model S car batteries, and the higher efficiency of 24 volt residential grade panels, it still requires a minimum of 1,400 watts of these panels, with about 400 to 440 amp hours of the 24 volt, higher efficiency batteries.
But, if you plan to use typical 12 volt RV solar panels, you will likely need more solar. We would recommend 1,800 watts minimum. This will cost you about $1,800.00 (typically costs about $1.00 per watt). If you plan to use common 12 volt lithium batteries, such as Battleborn, or Relion, we would recommend buying eight or nine of those batteries. Each of those batteries will cost about $1,000.00. So, you’re looking at about $8,000.00 to $9,000.00 in batteries, and another $2,000.00 in panels plus mounting equipment.
If you want to go with Tesla Model S batteries, they will cost about 50% of the price of common lithium batteries, but will output double the power because they run at 24 volts. If you’re serious about wanting to run your air conditioning unit from solar and battery, Tesla Model S batteries are the way to go. You can contact The BoonDoctor at his website… https://www.boondoctor.com/
Again, this is assuming you want to run that air conditioning unit for a minimum of four hours, up to a maximum of eight, per day, while still running your lights, fans, water pump, kitchen appliances, and recharging your phones and laptops.
You Will Need an Inverter Too
An inverter will convert battery power (DC) into 110 volt (AC) power. Air conditioning units will require 110 volt AC power. When you consider a 15,000 BTU air conditioning unit needs about 3,500 watts of power just to start up, you will need at least a 5,000 watt inverter. The reason is because inverters will convert DC to AC power with a 85% efficiency. So, a 4,000 watt inverter will realistically deliver 3,400 watts. Meanwhile, a 5,000 watt inverter will deliver about 4,250 watts.