How Long Will an RV AC Run on Two Batteries?


Running an RV air conditioner with batteries is very possible but it takes a lot of battery power. In this video I will show you how long a Dometic Blizzard NXT 15000 BTU air conditioner will run on two 100 amp hour batteries running on a Xantrex Freedom X 2000 watt pure sine wave inverter.

The components that I’m using are two lithium ion batteries from Greenlife, they are each 100 amp hours. We have our 2000 watt pure sine wave inverter by Xantrex. We are using a Blizzard NXT 2 RV air conditioner. This is a 15000 BTU unit that uses 1500 watts.

I wired the system for this test and I’m going to walk you through the process. I’m going to charge my lithium ion batteries to 100 percent, then we will wire in the air conditioning unit and run it off the battery.

I rewired the inverter so it will run the a/c. I usually have it run only through shore power but for this test I wired it to the batteries. You can see the voltage is starting to drop down to the lithium ion batteries resting voltage.

The go pro on the right will indicate the load in watts so we can see how much power draw we have. I will run this until I think it’s going to have a hard time starting the compressor on the a/c because I don’t want to damage these components.

The Test:
The fan has started and the a/c is running. The temp is now at 86 degrees, I have set it to 72 degrees and have the fan on low. We will be able to see when the compressor kicks on. We are currently drawing 182 watts of power.

The compressor has now clicked on, we are pulling 1100 watts. It will be much higher once the a/c really gets wound up. So far, the a/c is working and blowing cold air.

In about thirty minutes it has dropped the inside temperature by about five degrees. At an hour and twenty-four minutes into the test, I turned the a/c down to 66 degrees because I don’t want it to shut off during this test.

My low power warning is now going off, it has been a total of an hour and a half. I could have perhaps left it running for another twenty minutes but did not want to risk damaging my components. So, we were ultimately able to run the air conditioner for roughly 90 minutes on two lithium ion batteries charged to full capacity.
You would need four lead acid batteries to achieve the same results as you can obtain from two lithium ion batteries. I hope this gives you a good indication of what it really takes to run an a/c off battery power.

Those batteries each cost 1200 dollars, plus the pure sine wave inverter is around 600 dollars, so a total of 3000 dollars (not including the a/c).

I will have another video showing you how to use solar and battery power to run your a/c in a practical way. I have a 160 watt solar panel on my roof that was disconnected for this test, but for our next video I will show how to use solar and battery power in conjunction.

If this was helpful to you please remember to like and share. As always, thanks for watching and Happy Camping!

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24 replies
  1. JP Tucson, AZ
    JP Tucson, AZ says:

    Hello Jim,

    Very nice video on this subject!

    Being from AZ, getting rid of excess heat is always a struggle here in the Summer.

    That said, a few points to review & ponder; During your test, what was the outside temp.? This is important to see how much excess heat GAIN you also need to overcome.

    Of course during this test, you are starting from ground zero, no a/c running for some time with everything heated up.

    My contention on this would be to start off using the ac line power or generator to do the initial cool off to desired temperature, then switch to the batteries and see how long the battery/inverter system could maintain your desired/cooled off environment! I suspect in doing this, you would find that instead of only 1.5 hours that you might find your system would maintain perhaps 6 to 8 hours; battery only!

    Then you could do part 3 & add in the solar panels.

    Sounds like a good retest to me.

    Let me know the results…

    Thanks, John, Tucson

  2. John D
    John D says:

    Hi Jim, a first time ever on comments. I was looking to run air conditioning on battery power I found ya and I was impressed with your knowledge and love for what you do. This is my 3rd van build and all before I used a Honda EU300IS generator inside a closed compartment all year long. They are amazing little gen's. I would get between 3 thru 5 K hours before the rigs needed replacing.
    Anyway, I'm was talked into going with 600 ah of Battle Born batteries and a DC air conditioner form Proair. Do you have any experience with Proair AC units? I'm getting between 5-6 hours on the average. I have 2 questions if you would be so kind to respond to. At what voltage should I turn off the AC, below 12 volt? Question 2: I'm using a Colman 54 quart chiller that runs on a Kool Mate Converter ( 50/60Hz/120VAC 1.6A/192VA ) and wanted to know if I went with a cheap Walmart AC fridge. ( 120VAC / 60 Hz / 0.80A / or 0.64 kWh/ 24h ) Would I use less power on a daily use?
    No matter about the response, I really enjoy your channel and keep doing what you love. Thanks again for all you have done for the camping pep's………. Buzz

  3. mike brink
    mike brink says:

    I think a realistic goal for solar powered AC would be using a 5,000 BTU energy star rated AC…In a well insulated 10ft x 10ft = 100sq ft room/area (or insulated campervan)….. You could of ran a 5,000 BTU AC with the compressor running non stop for around 5 hours on that same setup….Most of the time the AC compressor is only running 1/2 or 3/4 of the time it's on and if you put in econo mode so the fan shuts off when the compressor isn't running, you could get around 10 hrs of cooling time on that battery bank.
    If you had 7 – 100 watt solar panels on the roof in full sun (producing about 500 actual watts) The battery wouldn't drain in the sunlight…..I'm not sure it's worth it to invest big money in a solar system if you're wanting to run AC….It'd be so much cheaper to buy/build a smaller solar system and when AC is needed run it off a small generator..$2,000 worht of gas will last a long time in a small 1,200w generator running a 5,000btu window AC plus you'll have a backup generator for rainy days….I'm kinda torn between AGM or Lifepo4 batteries….I plan to live full time in an RV/box truck or cabin in 4 season weather and don't want the Lifepo4 destroyed by accident in cold weather.

  4. theother account
    theother account says:

    1500 watts cant be correct for 5000 btu.My window unit is 5000 btu smallest typical unit you can find anywhere without over paying for a specialty shed dog house type then you could occasionally run into a 2500 btu double the price tag.Half the ac…but half the power draw on batteries an a small solar set up in a very small space it may be worth it if those prices were down to 150 bucks.

  5. or2169
    or2169 says:

    Your scaring me. Lol. So 500ah AGM batteries. How long will a 13500 btu AC run? Since the running watts is about 1250 watts. Which is roughly 10 amps. And I have an easy start on my AC. Which will reduce that initial amp draw. Hope you see this question and respond.


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