Fridge not working; 12V replacement?

[HikeSticks]

I have another question. I understand you can actually do a lot of harm to a propane fridge if it is not quite level when operating. Is the compressor style that operates on 12v/120v just as sensitive to level? If I can run the fridge/charge the batteries while driving it would be an attractive alternative to propane.
Thanks,
Barrie

[Evergreen]

Hi again, I can not answer this 100% but since people use these compressors on a sailboat that can crash over large waves and be at a 30 degree angle (done that myself leaving Bermuda heading to the Virgin Islands) I think they are OK and I plan on leaving ours on 24/7 all summer. I do know that the absorption fridges are used in some catamarans and power boats since they do not heel over, though they are not that popular. Sorry about all the sailing stuff but I have been sailing a lot longer than RV'ing.

[HikeSticks]

Originally Posted by Evergreen

Hi again, I can not answer this 100% but since people use these compressors on a sailboat that can crash over large waves and be at a 30 degree angle (done that myself leaving Bermuda heading to the Virgin Islands) I think they are OK and I plan on leaving ours on 24/7 all summer. I do know that the absorption fridges are used in some catamarans and power boats since they do not heel over, though they are not that popular. Sorry about all the sailing stuff but I have been sailing a lot longer than RV'ing.

Ahhh... yes, the last time I sailed from Bermuda to the Virgin Islands I forgot to take the fridge... . I wish. Thanks for the info!
Barrie

[Rick G]

Hi Barrie,

I wanted to throw in a few comments on this. As you noted in one of your earlier posts, there are two different types of fridges for RVs. The 3 way type (110V/12V/propane) are absorption fridges that work by boiling and circulating an ammonia chemical mixture. They need to be kept relatively level when parked (not when travelling) so that the mixture can circulate well through the small tubes. They work the same on all three power sources, by boiling the chemical, which requires heat. When running on electricity, they still work by heat, which requires a fair bit of power. My little Boler fridge had a 75 watt electric heater, and that was small. My current 1980 Dometic RM211 fridge is rated at 95 watts on the heater, and many are over 100 watts. That means your 12V battery would be drawing down somewhere between 7 and 12 amps, depending on the particular fridge. This will draw your battery down fairly quickly. However, the absorption fridge is the only type that can use propane, so that is why they remain popular. Once they reach the desired temperature the thermostat kicks in and out, which mitigates the power usage somewhat.

The other type is the compressor type, similar in theory to your home fridge. They generally are much better for power, anywhere from 25 to 50 watts depending on the size and manufacturer. So, your battery would only draw 2 - 4 amps, more or less, a much better power figure. They cannot use propane, only electricity.

If you had a low power compressor-type fridge, and given that a standard 1156 or 1141 incandescent 12V light bulb draws 1.4 amps, if you replace all of your interior light bulbs with LEDs you could almost run the fridge “for free”, that is without using any more power than you currently use for the light bulbs. That is a bit of an exaggeration because the fridge runs more often than lights in the daytime, but not much of an exaggeration.

Some time ago I did a 3-way fridge troubleshooting post, found here http://www.fiberglassrv.com/forums/f54/trailer-fridge-now-working-properly-42642.html#post214197 , and I am currently working on LED interior lights, found here: http://www.fiberglassrv.com/forums/f51/group-buy-of-leds-to-replace-incandescent-bulbs-44944-3.html#post239747

Hope that helps,
Rick G

[HikeSticks]

Thanks Rick. I appreciate the info. You reminded me of the traveling issue. Last year I took a few long trips with the 'egg'; New Brunswick to northern Ontario and another to Florida. I traveled somewhere just about every week last summer for 3-4 days. While I hope to travel less and park more this summer I know I will take a few long trips, such as to 'egg' gatherings, that will involve many hours on the road. The propane will work well when stopped but not when driving. If any of the 3 way units draws a lot of 12v power I'm concerned about getting stranded with a dead battery. Last spring I took a 7,000 mile, 25 state loop trip (not towing...) At 1:00 am one night I stopped in Ohio for gas and the car wouldn't start; dead battery. I had a 12v cooler with me that was the culprit. (I'm sure the battery was weak when I left...) Once burned, twice shy. I don't need a freezer and I want to ensure everything stays cool while traveling. The time between stops can be many hours. Mind you, if the majority of fellow 'eggers' have the 3 way they must be practical... Ahhh. What to do.
I have already switched all my lights over to LED.
Thanks again.

[Rick G]

I am not sure why your propane would not work while driving. Although some people feel that it is unsafe to drive with propane going in case of an accident, I have always run the fridge on propane while driving, unless it is just a short trip and the fridge would stay cold anyway. I had some issues with the burner flame being blown out while driving, but solved that by placing a wind shield around the burner, which stopped the wind but still kept the access to fresh air.

On the other hand, your car alternator should be able to (barely) keep up with the fridge if you run on battery. A typical car alternator is in the range of 30 (very old) to 50 - 70 amps, about 80% of which is used to run the vehicle. That doesn’t leave much for charging a trailer battery or running a fridge. Especially since standard tail/turn/stop lights use a few (2 - 4) amps each and incandescent side markers are at least an amp each. So, again, if you have LED exterior lights on your trailer, you would likely be able to run a fridge without cutting into your car battery charge very much or at all. If you find that you are depleting your car battery, you could run the fridge in segments. It is a good idea to stop every so often while driving anyway for a break, and you could just turn the fridge off and on each time. That would allow your car battery to charge up again if it needed to. But many people do not find that depleting the car battery is an issue, it all depends on how much capacity your alternator has left over after running the vehicle, and how much of a load your trailer puts on it.

Some people get bigger alternators installed, but the odds are good that you wouldn’t need to do that.

Rick G

[Bill K]

Barrie,
What kind of problem do you have with propane while driving ?

The reason I ask is I have used propane while driving and it worked fine.

Bill K

[HikeSticks]

Originally Posted by Bill K

Barrie,
What kind of problem do you have with propane while driving ?

The reason I ask is I have used propane while driving and it worked fine.

Bill K

Hmmm. No problem with driving with propane except my perception. I incorrectly assumed it couldn't/shouldn't be done. If the propane will work while driving it should be the solution to my problem.
Thanks for the assurance.
Cheers,
Barrie

[Bill K]

There are a lot of people that are against using propane while driving and there are some fridge's that will not stay lite while driving.

You need to turn them off when refueling.

Bill K

Originally Posted by Barrie Bochoff

Hmmm. No problem with driving with propane except my perception. I incorrectly assumed it couldn't/shouldn't be done. If the propane will work while driving it should be the solution to my problem.
Thanks for the assurance.
Cheers,
Barrie

[HikeSticks]

Originally Posted by Bill K

There are a lot of people that are against using propane while driving and there are some fridge's that will not stay lite while driving.

You need to turn them off when refueling.

Bill K

Now that I think about it, last November, while traveling to Florida, I did attempt to drive with the furnace on and at times it stayed lit and other times it went out. The same situation would apply with the fridge unless I was able to shield the intake. (as I noticed was mentioned in an earlier post) I have a battery meter I can plug into a 12v socket and now that I have swapped my lights to LED the battery has almost no draw and rarely needs recharging. With a 12v 2-way fridge I can leave the fridge on all the time, recharge the battery while traveling and not have to worry about stopping for gas... and the circle continues. The decision may come down to economics; which system can I get at the best price. My current fridge, used as an ice box, has served me in a pinch but it's not ideal. I really want to upgrade. I appreciate all the input. I now understand more than before and can make an informed decision.
Barrie

[bumblebee]

Do you still use your 12v cooler while driving? Has anyone else had that situation where it drained your truck battery? I am planning on buying one and wonder if I should buy a quick starter too. ty

[HikeSticks]

Originally Posted by bumblebee

Do you still use your 12v cooler while driving? Has anyone else had that situation where it drained your truck battery? I am planning on buying one and wonder if I should buy a quick starter too. ty

Last year I took a long (7,000 mile) road trip with my Miata. I started the trip with a 12v cooler on the seat beside me. I left it plugged in all day. Around midnight of the first day I stopped for gas and the car wouldn't start; the battery was DEAD. Granted, the cooler was an older one but fairly small and the battery wasn't new and may have been on it's last legs but... driving the car wasn't enough to maintain the battery AND run the cooler. It's possible that my experience was 'a perfect storm' of old cooler, old battery...) but if I were to do it again I would only run the cooler for an hour and shut it off for a hour...
BTW... I have replaced the fridge in my Trillium and now it works on AC or propane; I have not connected the 12v...
Barrie

[Alf S.]

Hi: All...Actually with our former 13' Boler the fridge worked best on 12V. while driving. The air bypassing the vents at 60 mph drew out the heat enough to make cellery popcicles and frozen head lettuce!!!
The BIGGIE thing to remember is to switch it off while sightseeing or stopped for shopping.
Our new 5.0 is only dual fuel propane/110V so we find we can drive 6hrs. or more with it off. If stopping/shopping etc. I try for a shady spot in the lot and just start the propane while not driving...or just simply keep the door closed!!! p.s. Barrie Maybe your fridge just needs a new thermal coupler...about 75 bucks from a good RV fridge tech!!!
Alf S. North shore of Lake Erie

[Evergreen]

I am planning on leaving our 12v Engel on as much as possible. I have not yet wired the TV charging system (just finally finishing the rebuild of our 13' Scamp) but are people using a battery isolator in the TV charging system? I would think that would remove the possibility of a dead TV battery? At least that is what I have planned...

[consumer]

absortion fridges running on propane use no power (except maybe a light in the fridge)
The thermocouple produces the power for operating the gas valve.

[Evergreen]

We will be living in the camper off and on for 3 months (when we are not there we will be back country camping). With 12v I can leave the fridge on while we are out and not worry about an open flame. We can also use the fridge while driving down the road. The only drawback I can see is the "system" is a bit more expensive than the propane fridge. The "system" includes solar, 110 charger, TV charging and 2 6v golf cart batteries.

[Alan P.]

The electrician who re-wired my Surf Side told me the switch for 12V/Shore power/propane condenser-type fridge could be left on 12V setting when plugged to shore power and it would make no difference to cooling performance or anything else. But it seems that the consensus is that it cools better on shore power setting, and best on propane. I'm going to study this on my trip and stay to Newfoundland. I believe that while rolling the only option I have to keep the fridge on is the 12V setting. I believe that using propane while rolling is a safety hazard - correct?
Alan

[cpaharley2008]

Originally Posted by Alan P.

The electrician who re-wired my Surf Side told me the switch for 12V/Shore power/propane condenser-type fridge could be left on 12V setting when plugged to shore power and it would make no difference to cooling performance or anything else. But it seems that the consensus is that it cools better on shore power setting, and best on propane. I'm going to study this on my trip and stay to Newfoundland. I believe that while rolling the only option I have to keep the fridge on is the 12V setting. I believe that using propane while rolling is a safety hazard - correct?
Alan

Yes, that is the consensus, 12v while en route, propane or shore power while camping.