Using Dometic refrigerator on 12 volts - Fiberglass RV


Reply
 
Thread Tools Search this Thread Display Modes
 
Old 01-06-2018, 12:05 PM   #1
Member
 
Name: Nigel
Trailer: Scamp 13
Minnesota
Posts: 68
Using Dometic refrigerator on 12 volts

There may be an existing thread for this question that gives an explicit answer, but I haven't found one and I'm finding the math confusing.
How long can I run my Dometic fridge on 12 volts when travelling in my recently acquired 1997 Scamp 13? Alternatively, should I NOT run it on 12 volts because I have a four-pin trailer electrical hookup? (I don't think this provides any charging to the battery)
I have a new deep cycle battery, 130 RC, understand it should not be run below half charged. The Dometic manual says it draws 10.5 amps and is rated at 25 watts. I'll be in Florida next week, with temps in the 70's so I figure the fridge compressor will be running at least half the time it is on.
Thanks!
nigeleccleston is offline   Reply With Quote
Old 01-06-2018, 12:33 PM   #2
Senior Member
 
David B.'s Avatar
 
Name: Dave & Paula Brown
Trailer: Lil Snoozy
Arizona
Posts: 2,206
Registry
Nigel, does your refrigerator also run on propane? If it does, you have an absorption refrigerator which does NOT have a compressor, but rather a heating element to heat the fluid in the system to turn it into a gaseous state, then circulate through the condenser and back to a liquid state. There is no duty cycle, as the heating element will stay on all the time. There have been discussions on this site about some WITH a 12 volt wire from the tow vehicle to keep the trailer battery charged while under way, not being able to keep up with the demand/draw of the heating element. This situation leaves the trailer battery dead upon their arrival to their destination. I would estimate your situation to leave your battery 50% discharged in a few hours.
Dave & Paula
David B. is offline   Reply With Quote
Old 01-06-2018, 01:04 PM   #3
Member
 
Name: Nigel
Trailer: Scamp 13
Minnesota
Posts: 68
Thank you! Yes I do have a three-way. I read a few posts from people who keep their fridge cold using propane while driving, I'll go back and see what the downside of that might be. I can always just bring along a cooler and transfer things to that while I'm driving.
nigeleccleston is offline   Reply With Quote
Old 01-06-2018, 06:00 PM   #4
Senior Member
 
TomK's Avatar
 
Name: Tom
Trailer: Scamp 16
Michigan
Posts: 864
Hi Nigel, there are lengthy discussions on this forum about the questions you asked. We had the same 3-way 1.9 c.f. fridge you had on our Scamp 13. We found the best solution to traveling with foods that need to be refrigerated was to freeze a couple juice bottles in your home freezer and use them as ice and the fridge as a cooler. When you get to your destination, there will still be ice in them. Those square shaped juice bottles (Ocean Spray, etc.) fit very well. Sometimes we use water, sometimes the juice they contained. Drain a little for expansion and freeze. If you don't open the fridge much, you will be surprised how long the ice lasts. A friend with much more experience than us showed us that method.

It helps to run your fridge for a day or two on 110 AC before you leave. We also traveled with a small cooler for the things we needed for the trip, and for side trips when in camp. The juice jugs work fine in there as well. Seems like 50-50 split on how safe it is to travel with the fridge running on propane. Most say you vehicle won't keep your trailer and your tug battery charged when fridge is running on 12V. I found neither of those options were necessary by using the fridge as a cooler. Enjoy your Scamp!

Tom
TomK is offline   Reply With Quote
Old 01-06-2018, 09:05 PM   #5
Senior Member
 
Raspy's Avatar
 
Name: John
Trailer: Black Series HQ19
Smith Valley, Nevada
Posts: 2,177
Using 12 volts to run a heating element in the fridge will run the battery down quickly. If you can charge it while driving you can overcome this load, but with a four pin connector I don't think you have a charging wire. Even if you do, you'll have to determine if the TV provides enough power to run the fridge and charge the battery. Then, when stopped for the night, you'll have to shut off the 12 volt system and start the propane system to protect your battery power.

Probably better to run the fridge on propane while driving, and on 120 volts while plugged in. I do and it's never been a problem.

Some have expressed concern over running the propane system while driving, or that there are some spots, like tunnels, where you can't.
__________________
I only exaggerate enough to compensate for being taken with a grain of salt.
Raspy is offline   Reply With Quote
Old 01-07-2018, 01:00 AM   #6
Member
 
Name: John
Trailer: Casita
California
Posts: 52
The majority of TV's can't charge the battery and run the fridge while towing. A few can. It depends on the size of your alternator and the wiring to the trailer. It's safe and legal to run your fridge on propane the road. There are a very few well marked tunnels where you need to turn it off as well as all ferries. Many RV refrigerators don't even have a 12V option. I have the same fridge in my Casita and always run it on propane. In a poll on the Casita Facebook page with 221 respondents, 69 said they run the fridge on the road on 12V and 152 said they use propane. Any formula to determine how long you can run your fridge while towing would have to take into account the output pf your alternator and the voltage drop over the wires between the alternator and the battery for your particular TV and trailer.
Ziggy is offline   Reply With Quote
Old 01-07-2018, 10:39 AM   #7
Senior Member
 
Name: Charles
Trailer: Scamp 16
Ohio
Posts: 295
Hey Nigel,
I use propane when traveling. 12 volts sucks the battery dead rather quickly.
I am headed to Florida on Tuesday. Was going today but the weather isn't in agreement. Where in Fl are you headed? I'm going to St Pete.
cmartin748 is offline   Reply With Quote
Old 01-07-2018, 10:41 AM   #8
Member
 
Name: Nigel
Trailer: Scamp 13
Minnesota
Posts: 68
Thanks, everyone, for the advice. Since I'll be starting from Minnesota, the fridge will be cold to start with (and too cold for some items). I'm going to use the fridge as a cooler as suggested by TomK and use the propane option if needed - definitely not 12 volts. I'll be doing a lot more camping than travelling, all with electrical hookups, so I think I'm all set!
nigeleccleston is offline   Reply With Quote
Old 01-07-2018, 10:46 AM   #9
Member
 
Name: Nigel
Trailer: Scamp 13
Minnesota
Posts: 68
Charles, I'm heading to Fort Lauderdale (Easterlin Park) for the South Florida Folk Festival over MLK weekend and then Highland Hammock until 10 days at Fort Desoto beginning 1/21.
nigeleccleston is offline   Reply With Quote
Old 01-07-2018, 10:55 AM   #10
Senior Member
 
Name: Charles
Trailer: Scamp 16
Ohio
Posts: 295
Awesome! I'll be about 10 miles from Fort DeSoto thru 3/6 at Roberts RV Resort in St Pete
cmartin748 is offline   Reply With Quote
Old 01-07-2018, 11:58 AM   #11
Junior Member
 
Name: Alexander
Trailer: Escape 15B
British Columbia
Posts: 10
In some jurisdictions it is illegal to have the propane fridge on while driving. I would check the motor vehicle code for each area in which you are travelling. There is the ever present danger of fire should you be involved in an accident or when refuelling. Running with the propane on is a bad idea.
penderpaul is offline   Reply With Quote
Old 01-07-2018, 12:04 PM   #12
Senior Member
 
Glenn Baglo's Avatar
 
Name: Glenn ( second 'n' is silent )
Trailer: 2009 Escape 17B 2020 Toyota Highlander XLE
British Columbia
Posts: 7,133
Quote:
Originally Posted by penderpaul View Post
In some jurisdictions it is illegal to have the propane fridge on while driving. I would check the motor vehicle code for each area in which you are travelling. There is the ever present danger of fire should you be involved in an accident or when refuelling. Running with the propane on is a bad idea.
Not true.
If you can find such a law anywhere, please post it and the source.
You do have to shut propane off in some tunnels and ferries.
__________________
What happens to the hole when the cheese is gone?
- Bertolt Brecht
Glenn Baglo is offline   Reply With Quote
Old 01-07-2018, 12:54 PM   #13
Senior Member
 
TomK's Avatar
 
Name: Tom
Trailer: Scamp 16
Michigan
Posts: 864
Charles, I'm looking for a CG in or near St Pete from 19 Feb thru 6 Mar. when we leave Sebring. They changed the reservation rules at our normal CG at MacDill AFB in Tampa. Getting in there looks like it may not happen. Do you think Roberts may have any openings? Recommend it? Maybe send a PM so we don't tie up Nigels thread. Thanks.

Tom
TomK is offline   Reply With Quote
Old 01-07-2018, 01:11 PM   #14
Member
 
Name: John
Trailer: Casita
California
Posts: 52
Quote:
Originally Posted by Glenn Baglo View Post
Not true.
If you can find such a law anywhere, please post it and the source.
You do have to shut propane off in some tunnels and ferries.
While traveling with propane on is legal in every state in the U.S. and it's commonly done, it is restricted in a few areas in Canada.

RVDA of Canada - Provincial RV Regulations
Ziggy is offline   Reply With Quote
Old 01-07-2018, 01:22 PM   #15
Junior Member
 
Name: Alexander
Trailer: Escape 15B
British Columbia
Posts: 10
In British Columbia, the Transportation of Dangerous Goods Regulations require that the appliance tank valves be closed when your RV is moving. Likewise when refuelling and travelling on a ferry.

If you want to challenge Murphy's Law and travel with an open flame and run the risk of ending your holiday by being burned to a crisp so be it. I just hope we're not at the same gas station at the time.
penderpaul is offline   Reply With Quote
Old 01-07-2018, 01:57 PM   #16
Senior Member
 
Glenn Baglo's Avatar
 
Name: Glenn ( second 'n' is silent )
Trailer: 2009 Escape 17B 2020 Toyota Highlander XLE
British Columbia
Posts: 7,133
Quote:
Originally Posted by penderpaul View Post
In British Columbia, the Transportation of Dangerous Goods Regulations require that the appliance tank valves be closed when your RV is moving. Likewise when refuelling and travelling on a ferry.
While on a ferry, yes. The other regulation you refer to is about transporting large amounts of propane ( ie. commercial fuel trucking ). You need to find and reread the regulation.
__________________
What happens to the hole when the cheese is gone?
- Bertolt Brecht
Glenn Baglo is offline   Reply With Quote
Old 01-07-2018, 01:59 PM   #17
Senior Member
 
Glenn Baglo's Avatar
 
Name: Glenn ( second 'n' is silent )
Trailer: 2009 Escape 17B 2020 Toyota Highlander XLE
British Columbia
Posts: 7,133
Quote:
Originally Posted by Ziggy View Post
While traveling with propane on is legal in every state in the U.S. and it's commonly done, it is restricted in a few areas in Canada.

RVDA of Canada - Provincial RV Regulations
The chart you provided says either you can travel with propane on or that it's not regulated ( NR ) or not stated ( NS ). I see none that say restricted.
__________________
What happens to the hole when the cheese is gone?
- Bertolt Brecht
Glenn Baglo is offline   Reply With Quote
Old 01-07-2018, 02:13 PM   #18
Member
 
Name: Neto
Trailer: Scamp
Virginia
Posts: 81
In Virginia down around Norfolk you are required to stop for an inspection to i sure propane is turned off at the tank B 4 you can travel through the tunnels.

Pumping fuel i to your tow vehicle with a propane flame burning in your fridge could prove to be distarious should fumes co e in co tact with the flame. You say, My tow vehicle is quite a distance from the flame but you need to consider the person on the other side of the pumps and that distance to the flame.
Neto is offline   Reply With Quote
Old 01-07-2018, 02:15 PM   #19
Senior Member
 
Name: Wayne & Barbara
Trailer: Parkliner
Iowa
Posts: 1,122
Fridge on 12V

Our solution with our 2000 16 ft Scamp, and small fridge was:
First, we have a 7 pin connector to take care of electric brakes as well as charge the trailer battery while traveling.
Second, another camper told us that the Scamp's internal wiring has too much resistance in the fridge circuit, therefore we would get only 10.5 volts at the fridge terminals. So, I installed a length of 12 gage wire directly from the battery - with a fuse - to the fridge. (found a routing under the body and the wheel well, with a hole through to the fridge compartment). Now, we measure 11.5 Volts with the fridge on.
As soon as we get into camp, we connect to shore power, and 110V.
BE SURE to always switch all three off then turn on the ONE you want.
If boon-docking; use the LP.
Wayne Collins is offline   Reply With Quote
Old 01-07-2018, 02:17 PM   #20
Senior Member
 
Raspy's Avatar
 
Name: John
Trailer: Black Series HQ19
Smith Valley, Nevada
Posts: 2,177
Quote:
Originally Posted by penderpaul View Post

If you want to challenge Murphy's Law and travel with an open flame and run the risk of ending your holiday by being burned to a crisp so be it. I just hope we're not at the same gas station at the time.
I wonder how many people have actually been "burned to a crisp" (and not just medium well), from a fire caused by the pilot flame in an RV fridge?

The sky may be falling, but it doesn't seem like a real problem. People light cigarettes, have red hot manifolds, sparking alternators, broken spark plug wires and static electrical sparks at gas stations thousands of times a day. There are non-explosion proof light switches all over in cars and trucks, that operate brake lights, headlights, backup lights and ignition systems. Starter motors have exposed solenoid connections and high amp motors with sparking brushes. Where is the carnage?

I'd be happy to shut my system off in compliance with the law, but this argument went from Canadian Law to Murphy's law. Possibly a bit dramatic, unless it can be shown that there are a lot of crispy folks out there who, specifically, had absorption fridges running on propane, as the cause.
__________________
I only exaggerate enough to compensate for being taken with a grain of salt.
Raspy is offline   Reply With Quote
Reply

Tags
refrigerator


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Casita refrigerator needs 12 volts charliej Problem Solving | Owners Helping Owners 41 12-05-2012 11:08 PM
Using refrig on 110 volts with no battery Mark J Problem Solving | Owners Helping Owners 9 07-02-2012 10:36 AM
Installing a digital Amps/Volts Meter peterh Modifications, Alterations and Updates 21 09-10-2009 03:37 PM
Problems with Refrigerator on 120 volts John Blair Problem Solving | Owners Helping Owners 14 05-07-2007 02:55 PM
12 Volts provider for testing Legacy Posts Modifications, Alterations and Updates 2 06-05-2003 09:52 PM

» Upcoming Events
No events scheduled in
the next 465 days.
» Featured Campgrounds

Reviews provided by


All times are GMT -6. The time now is 04:53 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.