Traveling with Fridge on 12V?

[Mr Lynn]

I know this has been much discussed, but I'm still puzzled. *For short runs I usually just turn off the fridge, which stays cold for an hour or two. *Then in state parks without shore power, we run the fridge on propane.
*
We're heading on a two day trip Sunday. *I know some run their fridges on propane on the road, but I'm nervous about it, and would prefer to use 12V. *The issue seems to be whether the fridge will draw too much current and discharge the trailer battery, apparently because the tow vehicle can't keep up with the need. *Is this really likely? *And is there a cutoff in the fridge that will shut it off if the incoming voltage is too low?
*
We have a 2013 Ford Expedition with factory towing package, and a 2013 Casita SD 17.
*
/Mr Lynn*

[Glenn Baglo]

I've driven five or six hours with the fridge off. Just don't open it at all. Also helps to add ice packs to maintain temp.
But, I run on propane.

[Byron Kinnaman]

Originally Posted by Mr Lynn

I know this has been much discussed, but I'm still puzzled. *For short runs I usually just turn off the fridge, which stays cold for an hour or two. *Then in state parks without shore power, we run the fridge on propane.
*
We're heading on a two day trip Sunday. *I know some run their fridges on propane on the road, but I'm nervous about it, and would prefer to use 12V. *The issue seems to be whether the fridge will draw too much current and discharge the trailer battery, apparently because the tow vehicle can't keep up with the need. *Is this really likely? *And is there a cutoff in the fridge that will shut it off if the incoming voltage is too low?
*
We have a 2013 Ford Expedition with factory towing package, and a 2013 Casita SD 17.
*
/Mr Lynn*

There's a lot of misconception about food and temperature. If the fridge is pretty full when you leave it stay cold enough for many hours even in 100°F weather. If you're paranoid, umm concerned then place a couple zip lock bags of ice inside when you leave. For most week-end trips it's not worth worrying about. I recently drove for almost 4 hours with the fridge running and there were no problems, even keep insulin cold.
I've learned a few things about refrigeration and camping.
1. Insulation
2. Mass... The more stuff that's cold the longer it take to warm it up. Most won't remember the old ice box the ice delivering ice once a week. That the height of luxury for refrigeration.
3. Many things that go into a refrigerator don't really need to, but they do improve the mass.
Bottom line... Get refrigerator cold and fill it as far in advance as possible. (several days like 4 or 5 and keep it cold) Then don't worry.

[Raspy]

I've always run my RV fridges on propane while driving. The only difference between that and running on 12 volts, while driving, is slightly less propane use.

One of my units would blow out occasionally while traveling, so I made a nice little baffle and solved the problem.

[Gerry]

I too use the propane while on the road but I thought I did read somewhere at some time that this was ill-eagle ???
Any knowledge of this?

[Borrego Dave]

Originally Posted by Gerry

I too use the propane while on the road but I thought I did read somewhere at some time that this was ill-eagle ???
Any knowledge of this?

Only on ferries or some tunnels from what folks post. I've never had to turn it off in my travels.

[Gerry]

Thanks Dave , I knew about the tunnels ohh and by the way, my flame has never blown out due to air getting into chimney

[Jon in AZ]

Also must be shut off when refueling. Easy to forget.

[jennykatz]

We have the Americana series 6336 with an Escape 21 We use 12 volt for driving and have frozen water bottles in fridge and freezer and off course don't open for more then 8 hr days of driving and everything including ice cream still frozen in freezer .We do have the 160 watt solar and twin 6 volt batteries (230amps) It might get down to 50 % but back up to 100% in a few hours of sunlight and plugged into shore power at campsite . I've been reluctant to use propane and 12 volt works great for us Jim

[Mr Lynn]

Originally Posted by jennykatz

We have the Americana series 6336 with an Escape 21 We use 12 volt for driving and have frozen water bottles in fridge and freezer and off course don't open for more then 8 hr days of driving and everything including ice cream still frozen in freezer .We do have the 160 watt solar and twin 6 volt batteries (230amps) It might get down to 50 % but back up to 100% in a few hours of sunlight and plugged into shore power at campsite . I've been reluctant to use propane and 12 volt works great for us Jim

Well, you've got a lot more Amps than we do, I reckon.

Over on the Casita Forum, where I posted the same inquiry, folks say that the hazard is running down your trailer battery because the fridge draws more than the tow-vehicle alternator is providing to the trailer. One poster says his is a 6-amp difference.

I guess we'll just try it, and check the trailer battery (I have a little plug-in 12V voltmeter that indicates battery charge). If it gets below 12, I guess we'll just turn off the fridge until we get to our stopping point for the night. And we'll load it up with frozen food and ice.

/Mr Lynn

[floyd]

We use a couple of great value juice bottles filled with water and frozen in our deep freeze with the cap loose to prevent swelling. Just tighten the cap and place in the fridge. They are square, so they stay put and stack or allow stuff to stack on them. They last up to 5 days. They can be filled with tea our lemonaide or just good water from home, then as they melt you have good cold drinks.
Frozen water bottles can work the same way, but not carbonated drinks.

Also you can freeze some food items.

[Wayne Collins]

We always travel with the fridge on 12 volts. That is what it is designed for.
The TV's alternator has plenty of capacity to keep up, AND charge the trailer battery too.
Just remember to shut off the 12V switch when you stop for lunch, or any length of time, ..or unplug the 7 pin connector, to avaiod running down your car battery.

BUT, you should check the voltage across the 12 v terminals at the back of the fridge, with the 12V switch on. If it is less than 11 volts, you have excessive resistance in the wiring. I ran a 12 gage wire direct from battery to fridge, bypassing the converter/fuse box. That was in our 2000 Scamp.

[BARNEYCONE]

I would invest in a radio shack amp meter, check ref. Amp draw vs. Tv out-put, now we know!!!!
,

[Radar1]

If you run it in 12 volt mode then double check that your tow vehicle actually provides charging current. Some do, some don't, and some factory tow packages still need to have that line activated.
We only have a 120 volt/propane fridge in ours, so no 12 volt option for us. We use propane if we plan to drive more than a couple of hours.

[hwdornbush]

Originally Posted by Radar1

We only have a 120 volt/propane fridge in ours, so no 12 volt option for us. We use propane if we plan to drive more than a couple of hours.

We added an inverter so that we could convert 12vdc to 120vac and it worked fine. Our tow vehicle, Jeep Grand Cherokee, puts out enough current to keep the battery charged. I prefer to NOT have propane on while driving. This seems to be a comfort thing but I like the safety factor of not having one more inflammable thing while traveling.

[Civilguy]

Originally Posted by Mr Lynn

Well, you've got a lot more Amps than we do, I reckon.

Over on the Casita Forum, where I posted the same inquiry, folks say that the hazard is running down your trailer battery because the fridge draws more than the tow-vehicle alternator is providing to the trailer. One poster says his is a 6-amp difference.

I guess we'll just try it, and check the trailer battery (I have a little plug-in 12V voltmeter that indicates battery charge). If it gets below 12, I guess we'll just turn off the fridge until we get to our stopping point for the night. And we'll load it up with frozen food and ice.

/Mr Lynn

We towed home some four hours in the high 80's last week with a partly-full refrigerator. The frozen goods were still frozen and the cold goods were pretty cold when we got home, although the air temperature in the fridge had risen to about 48 degrees.

A net 6 amp load would drain your stock 100-amp-hour battery in roughly 8 hours as you can only draw down about half of the rated amps.

I can always tell when I have bumped the switch and gone on 12-volt refrigerator operation as the fan in the load center starts running almost immediately. (Yeah, I still haven't bought that switch guard you mentioned!)

I use an inexpensive little voltage gauge to be sure that I still have something above the nominal target minimum of 12.0 volts. (When doing this, it's best to measure the voltage with a minimal load, so that would mean switching the fridge off for a bit.)

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Keep us posted what you learn.

[Peg Davis]

We had a Casita 17ft for 6 years and always ran it on 12V while traveling. We pulled with a Chevy K2500 and it never drained our battery. Like you we are not comfortable driving with propane on but I know many do without problems.

[Byron Kinnaman]

If you leave the fridge off for a couple hours or more everything is fridge is spoiled and needs to be thrown away. It only takes a few seconds for a large block of ice to melt with temperatures above 32°F

DISCLAIMER... The above is a very far from the truth.

[ehoepner]

I always travel with the Frig on 12v dc. It keeps the Frig cool and I have no problem with Trailer battery discharge.

The problem people have when the trailer battery is discharged is related to the size of the wiring on their tow vehicle. Their tow vehicle wiring is to small for the number of amps the Frig pulls. Because the wiring is to small the wiring restricts the flow of electricity. Therefore the trailer battery is discharged because it is making up the difference in what is supplied by the tow vehicle and the requirements of the Frig.

Wiring sizes should be 10 gage, 12 gage is very marginal. 14 gage drains the trailer battery.

[Mr Lynn]

Originally Posted by ehoepner

I always travel with the Frig on 12v dc. It keeps the Frig cool and I have no problem with Trailer battery discharge.

The problem people have when the trailer battery is discharged is related to the size of the wiring on their tow vehicle. Their tow vehicle wiring is to small for the number of amps the Frig pulls. Because the wiring is too small the wiring restricts the flow of electricity. Therefore the trailer battery is discharged because it is making up the difference in what is supplied by the tow vehicle and the requirements of the Frig.

Wiring sizes should be 10 gage, 12 gage is very marginal. 14 gage drains the trailer battery.

Interesting. The Bargman cable bundle on the Casita from the TV connection says '2/10, 1/12, 4/14'. If that refers to wire gauge, then I have to assume the 2 10-gauge wires go to the battery. So the trailer should be OK. BUT, the wires on the Expedition to the 7-wire connector don't look thick enough to be 10, so that might be a stumbling block. . .

EDIT: Actually, two of the wires are thicker than the others, so they might be 10s.

/Mr Lynn