What car fridge 12v would you recommend?

This kind of thing has been discussed on here before......many times......at length.
Have you done any searching yet ?

Rough summary: You won't be able to leave ANY "real" fridge on all the time without also leaving the car ON too.
A thermo-electric model will be only slightly better.
Without the car in the "ready mode", the fridge will run down the small 12 V battery in just a few hours.

A MUCH better solution is to get a super efficient portable cooler and some "ice packs".
That is assuming that you have a "home base" to re-freeze and rotate the ice.

A pharmacy that specializes in medical "devices" may have some better ideas too.

 

As you've probably already found in your research, the ones using a compressor and refrigerant, like a household fridge, are considerably more efficient than thermoelectric ones, so I'd say you are right to scratch the thermoelectric ones off your list.

The difference is not so much in the electrical current they draw when running; I have a thermoelectric cooler that draws 4 or 5 amps and a compressor fridge that draws about 6. Those would be common figures for units that will easily fit in a Prius.

Where the efficiency difference comes in is that the thermoelectric one will have to run nearly constantly at that current to stay cold, while the compressor one will be able to cycle off, and draw more like an average of an amp or an amp and a half over time. That makes a large difference in how long your battery will hold up. (Also, you can just get tired of the racket from the thermoelectric one constantly whooshing away.)

As far as blowing a fuse is concerned, of course it's the running current that matters. The car's 12 V sockets are rated for 10 amps, so a fridge running at around 6 is not going to be a problem.

When I was shopping around, it seemed like a size around 28 liter was about the sweet spot for what will easily fit in a Prius. This photo shows @Terrell's CFX 28:



I saw very few, if any, dual-zone (freezer / fridge) units in that size. The dual zones started showing up at somewhat larger sizes, where you'd have to start thinking hard about where in the car you can even put the thing, and how much space you want to lose to it.

 

The "AstroAI" brand one I bought from Amazon works great. It's a compressor fridge or freeze, single compartment with a wide range thermostat.

It's got a battery protector feature, and it came with a nice long 12v cord for the car socket as well as a "laptop brick" to operate it from 120V household power.

Search for B088FDTTY4 on Amazon to see it. I got the smaller 16qt version.

 

Recently I was reading about some new designs in this thermoelectric type of cooling they actually have chips now boards with refrigerant and stuff built right into the board so I think there's some stuff coming down the pipeline that's quite new in this arena You should look into the white and technical papers from some of the refrigeration companies I was just reading about this about 3 weeks ago and a technical publication I don't know all of its applications I don't even know that the people that have invented discovered put the stuff together know all the applications yet

 

Sounds like one'a those research projects where they haven't worked out the punctuation yet.

 

You'll be seeing this stuff in product shortly and they're working with it right now.

 

Tom, A thermoelectric cooler does not have any "refrigerant". They use the Peltier effect to pump heat into or out of the insulated cooler.

I have one and have used it for more than 20 years when traveling with food that needs refrigeration. It was an available option for our 1996 Subaru Outback. It pulls about 4 amps at 12v and holds a 40 degree differential between the ambient temperature and the temperature inside the cooler. We also bought a 120VAC to 12v power supply at a truck stop to use the cooler indoors when required.

JeffD

 

Ha, ha, I know what you are getting at, and whom.

 

I suppose it's possible somebody could combine a Peltier element with a refrigerant cycle, for some kind of clever reason. I haven't thought about it enough to say what a clever reason would be, but maybe that's what the research was about.