Advice, please, boondocking on solar, using a DC thermoelectric cooler

Dometic makes a portable fridge/freezer that works off of 12 VDC or 120 VAC. We were at the Jeep Invasion in Wildwood, NJ last year and Dometic was there showing and selling these units. The one we looked at was a fridge/freezer. Very good unit and it really does stay cold and the freezer does freeze ice. Yes, a little pricey. The one we were looking at was $1200. But this is a unit you can pre-chill/freeze before a trip. You plug it in you TV 12 VDC power point to keep it cold/frozen. The unit monitors the battery voltage coming in and will turn itself off if it detects a voltage drop. We spoke with a few folks that already had them in theirs jeeps and they swore by them. These folks only do boondocking in their Jeeps.
The DW and didn't get one since we decided we usually camp with hookups so not worth it. But if we camped more without hookups we would have purchased it.

Here is the Amazon link: https://www.amazon.com/Dometic-CF-080AC110-Portable-Refrigerator-Capacity/dp/B005X9KO86

 

I will jump in now that silvermikey kicked the gorrila in the house.
JMHO thermoelectric will cause you more anger than most people that have them admit. I Used one for almost 5 years before I sold it on letgo for $20.
Coleman claims 48 total amp draw in 12 hours as it will run at 100% when turned on!
In reality you only have 120 ah of usable battery not 240. You should only use no more than 50% of your total ah as you will start to weaken your battery bank. You could possibly drop them to 40% if they are AGM's without damaging them provided you get them back to at least 85% as soon as possible.
The power chill can not be loaded with as much as a 12v fridge/freezer as it requires room for airflow and by adding frozen water bottles you just as well use a Coleman Extreme Cooler and use the money on your vacation.
45-60 qt 12v fridge/freezer weight about 5 lbs more than the power chill and you should always fill them as full as possible as the cooling is on all 4 sidewalls and bottom not requiring any airflow.
There are cheap versions $399 in Amazon that will only draw a total of 12-20 ah in a 12 hr period depending on how full it is loaded and how often you open it. https://www.amazon.com/Costway-Portable-Refrigerator-Electric-Camping（-4°F/dp/B07CG4Q1YJ/ref=sr_1_9_sspa?keywords=40+qt+fridge+freezer&qid=1563205343&s=automotive&sr=1-9-spons&psc=1
Please read What Type of Fridge section at least in this link from our brothers and sisters from Down Under as they have tons of knowledge about this dead horse.https://www.exploroz.com/Vehicle/Accessories/Fridges.aspx?s=fridge
I have been using a small ARB F/F for over 20 years with no maintinance require other than 1 fuse. I have a 60 qt Norcold and have been using it and abusing it for over 10 years now.
A 12v F/F is an investment that will give you years of pleasure and can be resold if necessary for a good price as they are always in demand in the Off-road and Overlanding world.

 

^
Hmm, was wondering why my foot was hurting!!!

A the Jeep invasion we saw quite a few Jeeps that were modified to have kitchens in the back of the Jeep. Many of them had the Dometic units in there and those were the folks we spoke to. Are they pricey, yes! But the 3-4 folks we spoke with really loved the units.
We could not justify the cost at this time. Maybe in the future. But being able to travel like we do with or without the pup having a fridge in the back of our SUV will save me a job every morning or draining and putting in new ice. We can just take it up to the hotel room and plug it in.

 

I have one of those 12/24/240V fridge/freezers (our mains is 240) and I highly recommend one. Mine is a fairly large dual zone (2 individual compartments that have independent temperature control) You can run it as 2 x fridge, 2 x freezer or as a fridge and freezer. I haven't used it as a freezer yet but in 2 x fridge configuration it uses less than 1.5 ah and has no trouble keeping things cool. I usually fill it the night before and run it off mains power to cool it down. Another bonus for me is using it outside at home when we have outdoor parties or a BBQ.

 

What advantage do you think you are getting with salt water ice blocks vs. plain water ice blocks?

 

What is the Latent heat of ice for Fusion (melting-freezing) of water-to-ice for melting (unless its significantly greater for salt ice - I prefer to have my water drinkable in case I need it in the outback). And since salt water has a lower freezing point, does that not mean that it melts sooner in your cooler than plain water ice (if you started with both types of ice at the same temperature in your house freezer)?

 

We'd not use the salted water since we'd like to drink it in the case we happen to run out of potable water.

 

It makes no difference when it melts, only what temperature it is.

 

try this video linked in his blog


I have no need to make my cooler cooler in the short term so I do not use salt-ice. My goal is keep food below 40F and there would be insignificant difference for that. Fresh water bottles kept my vacumed sealed meals frozen for days and I used one bottle a day to keep lunch cool and drink.

My unfair ice test went like this, put frozen fresh and salt water bottles in the sink and witness which melted fastest. The salt ice melted funny and melted fastest. Try your own fair/unfair test!!!

 

Like I said, it doesn't matter when it melts only what temperature it is. I freeze fresh water down to minus 20 F. If I froze salt water right next to it, it would still be minus 20 F.

 

give it a try and measure the liquid's temp and remember that liquid transfers heat better so the melted saltwater is colder than fresh water melt. Regret the video did not show you that. One would keep your ice cream firmer than the other.

 

We keep our water in our water jugs, and not in our food cooler. Opening the food cooler means introducing heat, the adverse effect of what we desire.

Didn’t mean to start a holy war on the salt block comment. I just know what works practically for us on our trips, and crushed ice isn’t it. I think it’s the combination of block and salt content that makes it work. I couldn’t keep crushed ice in our cooler for two days before it melted due to exposed surface area and contact with the walls of the cooler.
Say what you want, but it just works. The previous picture of the block after 4 days should speak for itself.

 

Its not liquid water, its in a bottle. You are arguing basic physics.

 

After reviewing the pictures, I realized that it wasn’t four days. I apologize, It was 5+.

I put our ice blocks in the cooler on Sunday June 23 at approximately 3PM. Here’s another picture of the block and the time stamp. It just works.

6-28-19 Ice Block by 8lugnutz posted Jul 16, 2019 at 7:21 PM

Sorry for hijacking the thread.

 

correct basic physics. The big energy in ice is in the phase change that happens at a lower temp in salt-ice. It melts at a lower temperature.

The outside of frozen fresh water is 32F once liquid is present in or out of a bottle.

 

In a bottle you do not get liquid saturation. Change of state details might be important on a physics exam for a masters but not here. The ability to keep a cooler cool depends mostly on the actual temperature of the material and to a lesser extent the specific heat of the material. Salt water in a bottle will act no different than fresh water in a bottle or a block of steel.

 

Correct, it will act no different. But it will be colder and last longer.

 

nope!

 

It will not be colder. The cooler temperature will equalize

Just "nope" explain.

 

I have tried with repeated incorrect rebuttals