Will these power sources keep my RV refrigerator running while driving?

Hi, Dave,
My rig now has three Deka Intimidator AGM 12-volt 105-Ah batteries (Group 31). I installed three 250-watt solar panels along with a HQST 60-amp MPPT Solar Charge Controller connected directly to the house batteries, bypassing the inverter. Should this setup along with my diesel’s alternator allow me to run just the original refrigerator during travel days of 4 to 5 hours? I also have a Freedom SW 3012 Xantrex inverter. Thanks for your time and expertise! —Wayne, 2003 Winnebago Journey DL

Hi, Wayne,
According to the Winnebago brochure online, the Journey came standard with a Norcold double door refrigerator and had an option for a double door with an icemaker or a four door option. It looks like all three were absorption, meaning they could run on LP or 120-volt power.

Running the RV refrigerator on 120-volt power

I am not a fan of running the refrigerator on LP while driving, although you will find many owners that do it. So let’s look at running the refrigerator on 120-volt power through the inverter while driving.

With the new AGM batteries, you have 315 Ah (105 x 3) of which you should only draw down 50% State Of Charge (SOC)—so that means approximately 155 Ah. Since they are new and AGM, I would also assume they are not sulfated and have close to 100% capacity.

I don’t have the exact power specifications of your refrigerator running on 120-volt power. However, tests show a residential model running through an inverter can run approximately four hours on a 100 Ah AGM battery before getting to 50% SOC. So, I would estimate your refrigerator could last three times that, or 12 hours, with no additional charge.

Solar panels

Now, factor in the solar panels that will provide a charge if you are getting direct sunlight while traveling. That could produce 750 watts of power. However, most are under 80% capacity. That alone would be plenty to keep the batteries up longer than the 4-5 hours you need.

Then the diesel alternator will provide a charge through the Battery Isolation Management (BIM) solenoid. So, I do believe there is plenty of charging power to run the refrigerator for much longer than you need.

 You might also enjoy these posts from Dave 

• RV’s Norcold refrigerator is not cooling. Now what?
• How to disable auto defrost on an RV residential refrigerator
• Why does RV 12-volt refrigerator noisily cycle hourly?
• Should we run the RV refrigerator and the roof A/C between trips?
• Why does the RV refrigerator work on LP but not on 120-volt power?

Dave Solberg is a leading expert in the RV industry and the author of the “RV Handbook.”

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