12 volt Refrigerators

Would a 440 watt solar setup with 2 12volt group 27 batteries and the Dometic DMC 4101 fridge (rated at 156W) be a good option? I also have a generator, but do not want to have to run it every day to keep the batteries going. I almost always dry camp.

jeeperman wrote:
Lots of good thoughts here.
One thing I did not think of is dry camping
On cooler nights with furnace and fridge off the batteries
Two six volt may not last long

In a small trailer it's difficult to sleep with furnace on, it wakes you up every time it cycles. I've stopped using my furnace after bought Olympian Wave 6 catalytic heater. Sips propane very lightly and no 12V draw. Keep one window and roof vent cracked open a few inches and have working CO detector since this heater is not vented.

On the subject of fridges - I looked into 12V Danfoss babies 7 or 8 years ago, planned for this when installing 500W solar, but decided to let the OEM propane fridge be, for several reasons. I remember that back then (2013?) besides Dometic and Norcold there were also other 12V compressor fridges: Isotherm, Sundanzer, Canadian brand Novakool and one German brand that I forgot. This is not something new, they've been around for many years and still are. Sundanzer now only makes top-loading fridges.

To my observations, trailer/5er people who camp often on hookups replace OEM propane absorption fridge with a residential 110V compressor model (if there is enough space). Cheaper than 12V Danfoss units, better insulation, DC draw after inverter is significant but not much higher than with Danfoss fridge of the same size, because insulation is good. They don't care about DC draw, anyway. For an offgrid living it's a different matter.

Lots of good thoughts here.
One thing I did not think of is dry camping
On cooler nights with furnace and fridge off the batteries
Two six volt may not last long

You are talking about the "Danfoss" style compressors?

Not the crappie coleman ones or household refrigerators, both of which are very much the wrong choice for an RV.

YES, YES, YES! These are great refrigerators! Low amp draw, works at any angle (up to about 30 degree slope) and if you have solar then they are free to run.

I have two chest style fridges. An ARB and an Iceco. The Iceco has two compartments so is a freezer and a fridge. The ARB is just one so pick one temp setting and be happy...

I run the Iceco off two GC batteries and have 200 watts solar. It might draw the old batteries down 1/2 a volt to maybe 0.8 volts overnight if it is hot. Start at 12.6 volts after sun goes down and usually it is still above 12.0 in the morning.
The ARB uses less bc it is smaller...

Drawback is that in winter if you want to run the power hog furnace, which will need all the battery, then running both fridge and furnace (the fan is the power hog) together can really run batts down, so you need enough battery to handle that, but in winter, just turn off fridge overnight, it will keep cold.

IMHO, you will have success and be happy with either a DC compressor type fridge or household compressor type fridge run through an inverter if you spend the extra few dollars and add a couple 240 watt solar panels to the roof and an extra 200 amp hours of battery capacity.

Cheers.

A friend had a 12 V fridge factory installed when he bought his '99 Pete. He had to catch a plane home. By the time I got there, the truck had been sitting in a Dallas area truckstop for 4 Aug days. I knew he one had the same starting batteries I did, so expected to need to jump start the Cat.When she cranked on her own, I decided I would throw all the garbage out of fridge. Stole a ice cream bar, and headed home.

My sister's new Forester Motorhome has a 10 cu ft. compressor fridge. The interior space vs footprint is great!

It is too much draw for a single battery and dry-camping, unless you drive daily. With 2 batteries, it'll run about 3 days in hot weather (with cool nights) before needing to recharge the batteries from the generator.

OTOH - My absorption fridge will go about 10 days.

The compressor fridges have the added benefit of no leveling requirements. This is nice for my sister, since her driveway is about a 12% slope, and with the compressor fridge, she can leave it on between trips.

IMO durability is To Be Determined. I have concerns here. Hers feels "cheaper" than mine. And the travel lock was an afterthought. It's almost as if they took an apartment fridge design and simply swapped compressors. I don't think it will fit through the entry door if it ever goes out....

12V fridges have been around in the marine world for many years. Only now is the RV world jumping on board.
Here's an interesting test done using a 12V fridge.
JMO but I wouldn't touch a Norcold, Dometic, RecPro, etc brand 12V fridge if looking to replace a bad absorption fridge.
I would look to brands that have been around for a long time, like Novacool, Unique or the one in the test link.

https://www.rvtravel.com/rvelectricity-report-on-vitrifrigo-refrigerator/

Bob's reply is correct. For the person that dry camps the absorption system is still the best route as power consumption is minimal. Even with lower amp draw of the "danfoss" system; one needs a substantial battery system. IF I were to go the electric only route, I would choose the Norcold as they have been in use in the marine environment for decades and have a good record.

tewitt1949 wrote:
I had nothing but problems for 20 years with the OEM refrigerator. I finally threw it out and put a small house 120v fridge in. So much nicer since we are always have full hook up. We leave it closed until we get to where we are camping.

Comparing apples to oranges. Up until very recently all RV refrigerators have been absorption type, not compressor type. Home refrigerators have almost all been compressor type up until a few years ago. They were "old" style compressors that were either on at max cooling or off. (There were absorption type refrigerators made for household use years ago. As a kid it used to be my task to refill the kerosene tank on ours monthly.) Recent energy efficiency needs have made most home refrigerators inverter/compressor type which regulate the power needed to maintain temps and therefore CAN be much more energy efficient.

In the last year both Dometic and Norcold have introduced inverter compressor type refrigerators for RVs. Prior to that is was very difficult to find them for RVs, although there was a company in Australia making them, they weren't being imported to the US.

The 10 cu ft Norcold says it uses about 5amp, and from what I can tell the Dometic of the same size uses double that. There's not enough real world data on use in RVs to tell how they really stand up though, but it looks very promising for the future in the RV world. If they hold up and really operate on the stated power draws they'd work very well for dry camping with solar.

I do have an inverter/compressor "ice chest" that I've used for a couple of years in my RV. It has operated flawlessly and can freeze anything rock solid and keep it there with very little power draw.

BTW, the inverter/compressors used is sometimes referred to as Danfoss which is probably the company that did the original engineering. Most of the Danfoss units also appear to be manufactured in Japan.