12 volt refrigerator?

[multi-task]

Originally Posted by Lorelei L

Anyone install a 12 v fridge? How is it working for you? Do you use solar panels?

I exclusively boondock and use a Nova Kool fridge, draws 2.2-2.4 amps when running. My battery bank is two T-125's and a 215 watt solar panel.

I'd suggest sizing your battery to your electrical needs and how long you want to go with no charge. Then you either decide to make your trips a certain length before plugging in or choose a panel to charge your battery bank properly.

I've used my fridge in all temperatures, it's never failed and always kept everything cold/frozen.

[Raz]

Hello Lorelei. We have one member who loves his drip coffee when boon docking. As such he has installed extra battery capacity and an inverter. Others want a microwave. Bigger batteries. Bigger inverter. Next comes bigger solar panels or generators. I read about one fellow who ran an air conditioner off grid. Realize you can run anything you want if you are willing to throw enough money at it. As Carol has suggested the propane fridge is as simple as it gets. It will run a long time on one tank and keep your milk from going sour. But the compromise is performance; it will not match a compressor fridge. A compressor fridge will freeze your ice cream and cool your beer as long as you have the energy and the overhead to provide it. Which is better is subjective. Let us know what you do and how it works out. Good luck, Raz

[MCDenny]

We have a 3.6 cu ft 120v AC dorm fridge in our little snoozy with two t105 220ah 6v batteries and a 600w true sine wave inverter. It will run the fridge for 33 hrs before dropping to 50% charge and causing the inverter to fault out due to low voltage when the compressor motor starts. Running the inverter plus fridge draws 7 amps from the battery. This works pretty well but a 12v fridge with a danfoss compressor would run twice as long on the same battery power. Check out truck fridge.com. They look just like webasto units for half the price. A 4 cu ft model is $600.

If I had it to do over again I would have skipped the dorm fridge and put on a 12v danfoss unit.

[David Tilston]

I saw a 12VDC compressor fridge at my favorite wrecker for $25. I still kick myself for not getting it.

[David B.]

Some other benefits with switching to our NovaKool was the fact that we could immediately feel the cold after turning it on (important for 100+ degree days in Arizona) and could actually freeze food if not careful to keep the thermostat turned up. You do NOT need to level the trailer as it handles angles up to 30 degrees. It never blows out, nor does one need to switch from 12 volt travel mode to 110 volt while in RV park, to propane mode when off grid... just turn it on and forget it.

[Mike Magee]

My 3 cubic foot absorption type fridge won't keep stuff cold enough on hot days. Even when working well, this type of fridge will only reduce temps to about 35 degrees below ambient temp, if I recall correctly. So if it's 95 outside, the fridge is 60. That is why I'm contemplating a switch to a Danfoss type. I already have a 75W solar panel.

[jwcolby54]

Mike, I'm pretty sure this is not the case. I have the smaller unit but I turned it all the way cold and was getting low 40s when it was in the nineties out. It can struggle to cool a full fridge of new (warm) stuff, but once cold it says pretty darned cold.

Which is not to say a compressor type won't outperform it.

[Carol H]

Originally Posted by Mike Magee

My 3 cubic foot absorption type fridge won't keep stuff cold enough on hot days. Even when working well, this type of fridge will only reduce temps to about 35 degrees below ambient temp, if I recall correctly. So if it's 95 outside, the fridge is 60. That is why I'm contemplating a switch to a Danfoss type. I already have a 75W solar panel.

It must depend on the brand of absorption fridges. The old one in my trailer is about 4.5 cubic feet & it does struggle in the heat but I have managed to improve on it and it now stays in the 45 or lower range when temps hit the high 90's low 100's. I added insulation to around the outside of it and add a rear fan which made a BIG difference & leaving open the side vent helps as well. Also closed off any small openings to adjacent cabinets. Cant open it to often though as the temp will climb fast so best to keep cold drinks in a portable cooler. Have to watch it though if its set to cold the freezer will ice up and thats when its performance starts to go downhill fast.

[Spanke]

I had pretty much made up my mind to put in a Nova Kool R2600 12 volt fridge with the Danfoss compressor before this thread came along. This thread has not changed my mind.

My old Dometic RM211 was toast. I could have purchased a used unit or a new 3-way RM2193, but the cost difference between the Nova Kool and the Dometic was not that great and I liked the reviews, newer technology, power efficiency and interior size of the Nova Kool. Also, the depth of Nova Kool R2600 fits the available space better than the Dometic Rm2193.

It may not be for everyone, but for me, it seemed to make sense.

Spanke

[jwcolby54]

I quite agree. The downside is that is must use electricity, but it is so low powered that assuming solar (off grid) it is just a win!

[Mike Magee]

Originally Posted by jwcolby54

Mike, I'm pretty sure this is not the case. I have the smaller unit but I turned it all the way cold and was getting low 40s when it was in the nineties out. It can struggle to cool a full fridge of new (warm) stuff, but once cold it says pretty darned cold.

Which is not to say a compressor type won't outperform it.

Results with absorption fridges seem to vary wildly. Perhaps it's because conditions vary wildly. A thing or two not working optimally on the unit can throw performance off quite a bit. Heat element out of spec, some dirt on the coils, sun shining on the fridge side, trailer not quite level enough, air flow on rear of unit insufficient, partially plugged condensation drain, etc.

My unit worked just tolerably well for the first 2 summers, and worse for the 3rd summer. I talked to the service guy at the dealership where I bought the trailer, and he said they see it all the time in the 3 cubic foot Norcolds and don't really know what to do about it. I'm not much of a fixer-upper, so when the techs scratch their heads I figure it's time to look for something better. YMMV.

[multi-task]

One thing to remember when using a DC fridge and charging with solar, when your fridge cycles on during the day it will diminish your charging amps. For example, if your panel puts out 4 amps and your fridge cycles on using 2.4 amps you’re now only pushing 1.6 amps into your batteries. The big issue here is that most panels never output their maximum amps because most won’t have perfect placement of the solar panel, not to mention cloud, time of year, panel quality, etc.

This issue drove me nuts last year so I upped my watts from 75 to 215. Not everyone can do that but it fixed the problem. This season when my fridge cycled on it rarely mattered. However, bad sun is just bad, and that’s a whole other issue!

[Joe M]

I guess I am the oddball. I have a portable Coleman Power Cooler/Freezer. Uses a Stirling motor. Doesn't use much juice. Very light compared to Norcolds ect. Downside... Doesn't hold as much food.

[Lorelei L]

I know most of y'all are familiar with Harbor Freight. Is their 100 watt solar setup ok or is it crap?

[David B.]

Originally Posted by Lorelei L

I know most of y'all are familiar with Harbor Freight. Is their 100 watt solar setup ok or is it crap?

I have had their 3 panel 45 watt system for several years now.....still in the box(unused) because of the large "foot print" needed. I was going to use them on our 25' toy hauler, but now we have a 13' Scamp. Our 100 watt single panel Ramsond panel is almost the same size as one of the 3 15 watt Harbor Freight panels.

[Carol H]

Originally Posted by Lorelei L

I know most of y'all are familiar with Harbor Freight. Is their 100 watt solar setup ok or is it crap?

Lorelei, I havent seen their 100 watt setups - I looked at their online catalogue and couldnt find it but if like the others set ups I have seen I agree with David that their panels tend to be on the large size.

I purchased my panel 6 years ago and I know that today I could get a panel with 3 times the wattage at half the size and cost. The smaller panels are easier to find a safe spot to store in the trailer if you do not plan on permanently mounting them.

[Steve L.]

FWIW, I compared the HF 45 watt package to a 45 watt package from Northern Arizona Wind and sun and the HF package was 2.5 times larger (area). Plus, from the HF manual I wasn't thrilled with the following warning from the manual:

9. This product may occasionally produce more current and/or voltage than its rated output. Increase output ratings by 25% when determining component required voltage and amperage ratings. Refer to Section 690-8 of the National Electrical Code for an additional multiplying factor of 125 percent (80 percent derating) which may apply.

That's 25% in addition to what NEC recommends.

Not to offend anyone's sensibilities, but anything I buy at HF I consider disposable. YMMV.

[mmcwhort]

Originally Posted by Lorelei L

Anyone install a 12 v fridge? How is it working for you? Do you use solar panels?

If you're looking for a good 12V fridge, you should check out what the overlanding guys use. These are the people who do EXTREME camping, where they go on expeditions to third world countries and drive 200 miles off road to find a campsite. You'll see a fridge that looks like this on almost every rig.



They are built exclusively for 12V power, but unlike the Dometic fridge that Scamp sells, these have a VERY low power draw (0.5 to 3 amps at 12V), and work well enough to make ice in the desert. Your average group 24 battery can power one of these for 2 or 3 days, and with a good solar panel you can power it indefinitely.

Most of them open from the top, like a cooler. But I found one that opens from the front, and is roughly the same dimensions as the Dometic fridge that comes with the Scamp. It's the Engel SR70, and based on the installation guide, it should fit in the same cutout as the factory refrigerator if you widen it a half inch. I plan on getting one in the spring.

[Tim Wood]

Originally Posted by Spanke

Danforth 12 volt compressor refrigerators are no more expensive than a new 3-way ammonia type frig and are far more efficient. You can buy a 2.4cf for $639 + shipping here: Nova Kool R2600 68L Single Door Refrigerator (R2600) DC Only

This frig is pretty much a direct physical size replacement for the old Dometic rm211.

Since there is a compressor, they work much better than ammonia technology and you don't need propane or large vents on the side of your trailer. Only uses 3 amp when running. Easily can run a long time with only solar to replenish your battery.

If you have a generator to recharge you're golden. On shore power, if you have a converter, it only takes a 3 amp circuit to make it work.

Just more food for thought!

Spanke

David, I'm probably missing this, but I don't see where Nova Kool uses a Danfoss compressor . I do know that a lot of these 12v fridges don't use Danfoss like Engel, but are still an excellent fridge/freezer. Then there are others who aren't as efficient as Engel or Danfoss. I have a small Dometic chest type fridge/freezer and it does have a Danfoss in it, and is a great little fridge/freezer.

Ahh with more investigating I did find some more specs and the Nova Kool does have a Danfoss compressor, good find.

[Lorelei L]

Thanks for the Engel & solar panel info. I go to HF to stock up on basic tools & little LED flashlights for the kitchen tool drawer, because when somebody goes into mom's tool drawer, I know I will likely never see THAT screwdriver or flashlight again! LOL