Question about running the fridge on battery

[cpaharley2008]

There is a small cg in Pennsylvania Burnt Cabins Grist Mill
where we go several times a year. Their bread and rolls are all made with their own grains and the sandwiches are exceptional. We never take food with us because we purchase all our meals in their little deli using all local produce. A hidden gem.... and their take home jams and pancake/waffle mix wins prizes.

[ichrisdr]

I need help. I'm driving myself nuts thinking about this...trying to figure out this question....I just drove 8 hours with the refrigerator on DC. Before I left I let the refrigerator run for 2 days on AC and it was cooled down to 35 degrees. After my 8 hour drive on DC the refrigerator was about 55 degrees but my batteries were still at full charge. So what happened or what is not working? My tow vehicle is a GMC Sierra with a tow package and I have solar.

[cpaharley2008]

It has been mentioned before, 12v operation just does not cool efficiently, stick to propane and 120v operation.

[bdornbush]

Originally Posted by cpaharley2008

It has been mentioned before, 12v operation just does not cool efficiently, stick to propane and 120v operation.

For some of us, it works fine. I would suspect that something is wrong with the refrigerator 12v heater circuitry as my refrigerator cools just fine on 12V. The combination of solar and tow vehicle charging keeps my trailer batteries charged while the refrigerator stays cool on 12V DC.

[ichrisdr]

Originally Posted by bdornbush

For some of us, it works fine. I would suspect that something is wrong with the refrigerator 12v heater circuitry as my refrigerator cools just fine on 12V. The combination of solar and tow vehicle charging keeps my trailer batteries charged while the refrigerator stays cool on 12V DC.

Do you have the small or large refrigerator? I had a 17B and I had no problems with that one working on DC. I have the 6 cubic ft in my new 19. I'm on my second refrigerator. The 1st fridge stop working on my way home from picking the trailer up at ETI. It was replaced under warranty. This is only my second trip with the trailer and first with the new fridge. I'm suspecting that the current system set up just can't handle the larger fridge like cpaharley said. Sorry to beat a dead horse on this topic.

[Rossue]

Regardless, you have a different fridge from the ones used in Gen1 trailers. I too suspect a possible 12V problem, however did you pack the fridge too much? We only had a real problem once(and on propane) and that was because we stuffed too much fresh lettuce from the garden in ziplock bags that interfered with circulation. Similar experience: went from 40F to 55F in six hours.

[ichrisdr]

Originally Posted by Rossue

Regardless, you have a different fridge from the ones used in Gen1 trailers. I too suspect a possible 12V problem, however did you pack the fridge too much? We only had a real problem once(and on propane) and that was because we stuffed too much fresh lettuce from the garden in ziplock bags that interfered with circulation. Similar experience: went from 40F to 55F in six hours.

Hmmm the fridge is half full. Once I got to the campground and hooked up electric and switched fridge to AC it cooled right down. Are you suggesting a possible 12V problem in general across multiple trailers or a one off with my trailer? I would call Dometic but when my 1st fridge failed they told me to contact a service center.

[salmo7000]

Originally Posted by ichrisdr

Do you have the small or large refrigerator? I had a 17B and I had no problems with that one working on DC. I have the 6 cubic ft in my new 19. I'm on my second refrigerator. The 1st fridge stop working on my way home from picking the trailer up at ETI. It was replaced under warranty. This is only my second trip with the trailer and first with the new fridge. I'm suspecting that the current system set up just can't handle the larger fridge like cpaharley said. Sorry to beat a dead horse on this topic.

Hmmm, that could be and why there are so many conflicting reports. I've run the fridge in my 2018 19 on DC every time I've used it, and it's kept the temp under 40 degrees. I have the standard size though.

[Rossue]

Originally Posted by ichrisdr

...Are you suggesting a possible 12V problem in general across multiple trailers or a one off with my trailer?

I would think one off from your report.

[Jim Bennett]

As mentioned a while ago in this thread, I tested the 12V system running the half full fridge travelling on a sunny day, using my 240W of solar along with the truck power. After a good 6 hours the battery level had dropped a bit but not too bad, but the temperatures in the fridge rose quite a bit. I turned it back to propane and in short order the batteries were fully charged and the fridge temperature back where it should be.

While I would love the DC to work with the fridge while travelling and save a bit of propane, there is no way I will trust it, just not worth it for us. Should our fridge temperature ever reach over 4°C my wife starts to panic about a few of the foods not going bad, and there are few places where I must abide by my wife's wishes, but this is one of them.

[bdornbush]

Originally Posted by ichrisdr

Do you have the small or large refrigerator? I had a 17B and I had no problems with that one working on DC. I have the 6 cubic ft in my new 19. I'm on my second refrigerator. The 1st fridge stop working on my way home from picking the trailer up at ETI. It was replaced under warranty. This is only my second trip with the trailer and first with the new fridge. I'm suspecting that the current system set up just can't handle the larger fridge like cpaharley said. Sorry to beat a dead horse on this topic.

I have a gen1 small (5 cubic feet?) refrigerator. I would have your new fridge thoroughly checked by a local RV service place. As an aside, I have had good luck with a mobile RV repair guy here in my town.

[Fox hunt]

i always travel with my fridge on propane.

[Chotch]

Originally Posted by Jim Bennett

While I would love the DC to work with the fridge while travelling and save a bit of propane, there is no way I will trust it, just not worth it for us. Should our fridge temperature ever reach over 4°C my wife starts to panic about a few of the foods not going bad, and there are few places where I must abide by my wife's wishes, but this is one of them.

🤔 Lucky man

[tdf-texas]

Originally Posted by Fox hunt

i always travel with my fridge on propane.

Same here! We made a few trips with the Casita running the fridge on DC - every time the ice cream melted creating a sticky mess.

Lesson learned, no more fridge on DC.

[ichrisdr]

So today I kept the fridge on propane while traveling. Got to my destination and fridge was still perfect temp. So as other have said or suggested, DC may keep the smaller fridges cold but the larger fridge it is only good for short trips. I'm going to get a wireless fridge thermometer and experiment to see how long it stays cold on DC and completely off, with and without ice packs. Thanks for everyone's input especially from those of you who are constantly answering the same questions over and over.

[jamman]

On my fridge the 12V supply was never connected to the element. Read the installation manual for your model fridge and verify is is connected correctly. There MAY be an inline fuse in the 12V connection to the element, if so I would check that as well.

[ichrisdr]

Originally Posted by jamman

On my fridge the 12V supply was never connected to the element. Read the installation manual for your model fridge and verify is is connected correctly. There MAY be an inline fuse in the 12V connection to the element, if so I would check that as well.

Thanks I'll do that.

[Rossue]

Originally Posted by bdornbush

My Jeep Grand Cherokee with the trailer towing package DOES keep the batteries charged AND supplements the 150W solar enough that we arrive at camp with the batteries charged and the refrigerator cold, so it does happen. At least one of us (me) has a working solution, so it can work. Maybe Chrysler engineers have it worked out with big enough wiring. I have not checked the wire size but have no need to as it works for me.

How far do you drive to camp on average? Hard to believe it is very far. Then what- do you switch to electric or propane? Our experience with our 6.7 Dometic fridge is no way DC is going to work- and trying save some propane vs. the risk of food spoilage isn't worth it for us.

[ichrisdr]

@Rossue - For those concerned about running 12v vs propane it isn't an environmental issue or about saving propane, it's a safety issue.

[gbaglo]

Originally Posted by ichrisdr

@Rossue - For those concerned about running 12v vs propane it isn't an environmental issue or about saving propane, it's a safety issue.

I presume then that your tow vehicle has no fuel in it.
From Canadian Propane Association FAQ:

• Propane has the lowest flammability range of all alternative fuels (2.4% – 9.5%) – so there must be a very specific combination of propane and oxygen for it to burn.
• Propane’s auto ignition temperature is approximately 493° – 549°C (920° – 1020°F), gasoline’s auto ignition temperature is around 257 °C (495°F) – therefore, gasoline will burn or explode at a much lower temperature than propane.