Fridge Solution

[Darwin Maring]

Cold solution

COSTCO has these 12VDC electric coolers on sale.

https://www.costco.com/CatalogSearch...9_April_Mailer

[Alex Adams]

Review of the cooler:
https://www.reddit.com/r/overlanding..._cx50_ekooler/

Discussion about the cooler:
https://www.fordtransitusaforum.com/...-costco.80164/

[Lynn Eberhardt]

The mfg spec says avg power consumption is 40-50 watts. At 12 volts, that's 4 amps per hour - 96 AH per day. Not very suitable for off grid without a sizeable power system. Good while in transit.

[Darwin Maring]

Originally Posted by Lynn Eberhardt

The mfg spec says avg power consumption is 40-50 watts. At 12 volts, that's 4 amps per hour - 96 AH per day. Not very suitable for off grid without a sizeable power system. Good while in transit.

What would be perfect for off grid?

[Lynn Eberhardt]

The fridge that is probably in your Scamp 19 runs on propane. That's great for off grid use. The small unit you asked about would be perfect in your tow vehicle while you're driving and making the power to run it. It would use all the available power in 2 group 27 lead-acid batteries in 24 hours if you weren't charging them.

[Darwin Maring]

Sounds like it would be great for those that camp in campgrounds where they have power.

[redbarron55]

My Norcold draws ~4 amps when the compressor is running, but it runs about 1/2 the time for a measured 17 - 20 watts per hour average. About 2 Ah average X 24 for 48 Ah per day, but the solar provides power when the sun is shining so ...
For my100 Ah current battery it is a relatively marginal operation, but has worked OK so far.
This is why I am looking into LiFePO4 battery that can be drawn down to 80% instead of the 50% for lead acid.
We usually camp where there are hookups, but in emergencies and when in those parks that are in the shade (think Sequoia National Park etc.) the solar is of less use.

[Lynn Eberhardt]

Your Norcold system is workable, with newer batteries and solar panels now available. Your fridge seems to use half the power of the unit that started this discussion.

[redbarron55]

I wonder if the same thing as far as duty cycle holds true for the refrigerator in question. Once the refrigerator is at setpoint and the door closed it should cycle on and off as well.
One advantage to the Norcold is that it is a swing compressor and has no starting surge where the Danfoss style is rotary and has a fairly significant starting surge.
I tried an experiment with a small dorm fridge and a 300 watt inverter. The compressor draw was 40 watts, but the starting surge was more than my old inverter could handle.
One disadvantage of the swing compressor is that they can be noisy which is what predicated changing from a working Norcold 704DE to the 490DE which is smaller, but quieter (so far).

[Alex Adams]

Originally Posted by redbarron55

I wonder if the same thing as far as duty cycle holds true for the refrigerator in question. Once the refrigerator is at setpoint and the door closed it should cycle on and off as well.

It doesn't, read the discussion. Apparently there is little insulation so the compressor runs almost constantly when the ambient air is warm.

[CalCop]

A couple of years ago I replaced my Dometic propane with a Dometic 12/120volt danfoss. I bolstered by electric system by replacing the lead acid battery with a LIFEPO Battleborn 100ah. This change also meant a needed change of the old power converter. The addition of a 100 watt Renogy solar panel assisted in powering the battery.
So far I have no complaints with the system. Seldom does the fridge come anywhere close to draining the battery. As a test, I ran the fridge on battery power for 21 hours during August. At the end of that time I still had 30% battery charge. Did I mention being able to draw the battery to almost zero without degradation?
Problem with the chest type cooler, is where do you put it? Also, almost a 3rd of the chest is the cooling unit.

[Defenestrator]

Originally Posted by redbarron55

I wonder if the same thing as far as duty cycle holds true for the refrigerator in question. Once the refrigerator is at setpoint and the door closed it should cycle on and off as well.
One advantage to the Norcold is that it is a swing compressor and has no starting surge where the Danfoss style is rotary and has a fairly significant starting surge.
I tried an experiment with a small dorm fridge and a 300 watt inverter. The compressor draw was 40 watts, but the starting surge was more than my old inverter could handle.
One disadvantage of the swing compressor is that they can be noisy which is what predicated changing from a working Norcold 704DE to the 490DE which is smaller, but quieter (so far).

The start surge isn't really about the compressor mechanism so much as the motor type. From what I can find on the Danfoss compressors on their site, they're "variable-speed", which implies brushless DC, which shouldn't have any significant starting surge.

The dorm fridge is a single-phase AC motor, which does have a lot of starting surge.

[redbarron55]

"The start surge isn't really about the compressor mechanism so much as the motor type. From what I can find on the Danfoss compressors on their site, they're "variable-speed", which implies brushless DC, which shouldn't have any significant starting surge.

The dorm fridge is a single-phase AC motor, which does have a lot of starting surge."
This may well be correct on the Danfoss, but I don't know for sure.
The difference in the rotary compressor is that the piston has to make a full stroke against the residual pressure to get moving, even if there is no surge like an across the line starter. The starting "surge" would be significantly less with a VFD and ramp up if that is what happens with the Danfoss.
The swing compressor has pistons, but they are operated by a solenoid that bounces the piston(s) back and forth and do not have to make full travel to start, but build up pressure more slowly.
The drawback is that this rattling back and forth can be noisier than the rotary units.
The Sawafugi compressors are very efficient, however. I don't know if the Danfoss or Sawafugi compressor is inherently more efficient as the insulation and application makes a lot of difference.

[Martin.P]

Check out the ARB Fridge. We love ours.

[Lane Noyes]

Originally Posted by CalCop

A couple of years ago I replaced my Dometic propane with a Dometic 12/120volt danfoss. I bolstered by electric system by replacing the lead acid battery with a LIFEPO Battleborn 100ah. This change also meant a needed change of the old power converter. The addition of a 100 watt Renogy solar panel assisted in powering the battery.
So far I have no complaints with the system. Seldom does the fridge come anywhere close to draining the battery. As a test, I ran the fridge on battery power for 21 hours during August. At the end of that time I still had 30% battery charge. Did I mention being able to draw the battery to almost zero without degradation?
Problem with the chest type cooler, is where do you put it? Also, almost a 3rd of the chest is the cooling unit.

And the total cost of all that was?

[Motoboss]

Yeah, we're on the hunt for a new fridge and seriously considering 12v, but..

Fridge $700. to $1000.
Litho batteries $1000 each
Solano panel 100watt - $300 each
Controller $75-$200
New converter $250

So conservatively, set up around $2400.00!

Can't quite get on board just yet.

Other option is a 3 way, run on propane (and deal with the inefficiency, need to level, etc..) but $1000 to $1600 doesn't seem much of a deal either.

I've considered the ARB chest but in a Casita mounting is the challenge, and said and done quite pricy also once a long life battery is included.

What to do,,,,,,,what to do..........

[CalCop]

At this point in my life I don't need or tolerate frustration well.
Earlier I mentioned I replaced the propane fridge AKA: Ice Box.
After years of working on mods in the hopes of actually having something reliable as a fridge, I went to the dark side and installed a 12volt fridge.
The change over wasn't cheap. But the benefits outweighed the cost. I no longer have to buy ice or worry about spoiled food. The unintended benefit of bolstering the battery system also reduced any concerns of battery power.
Propane fridge $1200 to $1500
12 volt fridge $1200 to $1500
LifePo Battery $700-$1000 weighs 33lbs Lead acid battery weighs 61lbs
100 watt solar panel $100, controller $5 to $200
Possible converter change out to support the LifePo $200 to $25
This of course is just a parts list. Installation of the fridge can be labor intensive.

[Wyowill]

Pulled the icebox out of our Scamp. Built shelf to support TF65 Truckfridge. Added dedicated power wire and fuse. Slid Truckfridge into opening, 4 pop rivets into existing holes from icebox. Life is good.
100 watt solar mounted flat on roof, group 29 deep cycle battery. Many miles and 6 plus years still works great.
KISS principle in action my friends.
Truckfridge TF 65 now on sale for $599!

[Iowa Dave]

In addition to our Dometic Refrigerator in the Escape we have an Engel cooler. It draws .8 to 2.8 amp hours on about a 40% duty cycle. It runs on 12volt or on 110AC. We can turn it up and it will keep things frozen or set it outside and run it on the outside 110 when we are setting out for awhile. When traveling without the camper we put it in the back of the Highlander and run it on the 12v outlet in the Highlander. We have had it three years and it has been trouble free. If we are crowded in the Escape we put it in the Highlander at night. But when it’s just the two of us it sets on the floor in the Escape. We crossed Kansas and Nebraska a couple times when it was about 100 degrees. The Dometic 8555 just can’t keep up but the Engel will drop the temp 70 Fahrenheit degrees from ambient and you gotta be careful you don’t freeze the lettuce.
If the 8555 ever conks out, we will buy a second Engel and run one as a fridge and one as a freezer. Remember, it’s only money and there’s no substitute for cold beer.

https://www.google.com/search?q=ice+...QgAZfCtg4UAAAA

Iowa Dave