Updated Feb 26 2020
Whether you’re heading out for the weekend or spending months in an RV, you need a way to keep your food cold. Unfortunately, getting a fridge to run off of 12V is a little challenging. And when you go to research the topic, you can be left with even more questions than answers!
Everything You Need to Know
Can I just run a normal bar fridge off an inverter?
What about that camping refrigerator from my old RV that ran off 12V, propane, and 120V?
How about those cheap 12v coolers that just plug into my cigarette lighter?
Unfortunately, if you’ve asked any of those questions then you’re headed down a pretty disappointing path. Luckily, we’ll show you the specific things you need to look for to find a high quality 12 volt refrigerator that will last a long time and won’t kill your batteries! First, we’ll look at the most popular purpose-made 12 volt refrigerators. Then, we’ll show you what modes to avoid. Finally, if you stick around, we’ll show you a couple budget options for weekenders as well as a cool DIY project where you can build your OWN 12 volt refrigerator that performs just as well for a fraction of the price.
The Best (and worst) 12V Refrigerators on The Market
If you’re looking for fridge that will sip on DC power and keep cool in even tough conditions, you’re in the right place. We’ve written 7 seperate reviews and in this roundup we’re going to rank them from best to worst. You’ll find out which ones are the most energy efficient, requiring very low power to run. Additionally, we’ll check out some portable fridgerators that keep your food at safe temperatures for long periods of time. Without further ado, let’s get into the reviews.
Dometic CFX: Our Favorite Portable Refrigerator
The Dometic CFX 75DZW pretty consistently tops our list for it’s incredible performance, versatility, and reliablity. Don’t let us confuse you – this is NOT an economical option. Dometic has been a top brand for over 30 years and there is a good reason for it – they spare no expense. This is a no-compromise 12v refrigerator for overlanders and RVers who require reliability and performance above all else. Your power consumption will be low, and it will hold the temperature within a safe range consistently to prevent food spoilage. Aside from that, it’s extremely durable (if not a bit heavy) making it one of the best DC powered portable fridges available. If you can spring the cash for it, this is the model to buy.
Dometic CFX 75DZW Review At a Glance
|✔ Top of the pack
✔ Extremely Solid Build
✔ Dual Compartment Temp Zones
✔ Tons of nifty features
✔ Fantastic Reliability
|X High Price
X Heavy Weight
X Nothing new and exciting
If you want to read our full review, check out our full dometic CFX 75DZW here.
Engel: One of the Most Popular 12V Refrigerators
If you’re looking for a slightly more affordable model that still has the performance, reliability, and name to back it up, Engel would be our second choice. They are a little more portable than some DC power 12V refrigerator models, and have many features that your bone standard portable fridge just doesn’t offer. We like them for their great temperature ratings and their ability to hold these temperatures consistently without huge power draw. They are a great choice for solar or RV applications, and run exclusively off 12 volt so you know that they are specially made for your portable fridge needs.
Engel Fridge Freezer Review At a Glance
|✔ Great Temperature Rating
✔ Low power consumption
✔ Easy to Mount
✔ More economical price point
✔ 12 volt compressor by default
|X Need to be mounted for best result
X More complicated setup
X Wider temp range than Dometic
Yep, Engel is one of our top choices again. If the brief overview didn’t give you enough facts, check out our full engel fridge freezer review here.
Whytner: A Great Budget Camping Refrigerator
So far we’ve only looked at high end 12V fridges for situations where DC power is at an absolute premium. What about more casual uses? If you just want to take the old RV out for a weekend trip, the Whytner FM-54G is a great buy. It’s half the price of others, and teh slighlty higher power consumption won’t matter for weekenders or those who have higher capacity DC power systems. Overall this is a great brand at a low price and shouldn’t be overlooked.
Whytner FM-45G Review At a Glance
|✔ Simple, reliable design
✔ Acceptable power consunption
✔ Moderate temp variation
✔ Very affordable
✔ Well made
|X Not ideal for long term use
X Requires decent 12v power supply
X Battery protection recommended
It’s not the most expensive, but it still packs a punch. Learn all the details in our full Whytner FM-45G Review.
ARB: Might Not Live up to the Hype
Yeah, this might come as a surprise to many of you. ARB is a BIG brand and they have a solid following and sell a LOT of 12v refrigerators. And we’re not going to say they are the worst product on the market. Because believe me, you could do WAYYY worse. Really, our problem with the brands products is that, in our opinion, they don’t really hold up to the hype. For about the same amount of money, you can get something that’s more durable, more versatile, has lower power consumption and higher capacity. And to top it off, the temperature tended to bounce around a little – that kind of range can make your food spoil faster. If you’re an ARB fan than power to ya, it’s just my personal opinion that there are better options out there.
ARB Review At a Glance
|✔ Very well written manual
✔ Includes Mounting Hardware
✔ Well known brand
|X High power consumption
X temperature variance +/- 6°F
X Insulation doesn’t seem to last as long
If you REALLY want to know specifically what ticked us off about this refrigerator check out our ARB review.
Costaway 54: The Budget Option
Let’s get one thing straight: the 12V refrigerator market is dominated by the Overlanding and camping community. These are guys who want to spend weeks, months, or sometimes even years on the road. And if that’s your life, spending a couple grand on a 12V refrigerator is well worth it just in terms of food, nevermind the cost savings on solar and DC power equipment. But not everyone needs a high end cooler. Some guys just wanna throw their kids in the truck and haul the camper down to the lake for a few days. And if that’s the case, this guy just might do it for ya. You’re not going to get a weeks life out of your secondary battery, and it’s not going to perform as good as a unit that costs thousands of dollars. But guess what? It keeps beer cold. It keeps food cold. It’s better than a regular cooler, and it’s MUCH better than a peltier refrigerator. Yeah, compared to the TRUE 12v fridges on our list this doesn’t have a ton to offer, but it gets the job done for some people.
Costaway 54 12v Refrigerator Review At a Glance
|✔ Simple, reliable design
✔ Acceptable power consunption
✔ Moderate temp variation
✔ Very affordable
✔ Well made
|X Not ideal for long term use
X Requires decent 12v power supply
X Battery protection recommended
Don’t forget there are serious drawbacks when you are saving this much money. Check out our full Costaway 54 review here. And make sure this is the right choice for you before you buy.
What Are the Types of 12 Volt Refrigerators?
Look, lots of things are sold as as 12v refrigerator. But that’s not always what they are. However, there are several ways to keep food cool while on the go in a vehicle. And in this section, we’ll take a look at the main differences between your options.
The cheapest option is to get an electrically assisted cooler. These work much like normal coolers, but a small trickle of electricity helps to keep your ice frozen for a much longer period of time. This is great for the odd weekend out, but it’s a suitable full-time solution. This is called a thermoelectric cooler. It just takes heat from the inside and puts it on the outside. They are cheap, but they use a lot of power and only extend the life of your ice by 20% or so. They’re readily available, but we don’t recommend any of them.
In many cases, a proper 12 volt compression refrigerator is the best option. These come with a hefty price tag, although it is still cheaper than the fridge you have in your kitchen. What your money buys you is a surefire way to keep food cold (or frozen) while using very little power. These devices can easily be run off of your cars starter battery, or even off a very modest solar system. Additionally, they’re designed to take the bumps and scrapes that come along with life on the road.
Even if you don’t have the scratch for a commercially available 12 volt fridge, with a little elbow grease you can get something just as good. We’ll show you how to build your own by modifying a 120 volt unit. The project is easy enough to be completed by anyone with a little basic hand tool experience, and from a functionality perspective it works just as well. It’s a little bulkier, and not quite as sleek. But it’s 80% cheaper than commercial options, making it a great option for your rural cabin or RV.
What 12V Fridge Power Consumption Can I Expect?
Honestly, that really varies on your solar setup and the type of fridge you get. Some energy effecient models sip DC power and keep cool without much effort. The important thing is that you want to run them off REAL deep cycle or solar batteries, not your car battery. We go into great detail on 12 volt fridge power consumption. So click through if you want to know all the ins and outs. But in general, you can expect between 20 amp hours to 60 amp hours depending on the model.
A Primer on Refrigeration
Before we get into the nitty gritty details, it’s important to have a basic understanding of how fridges work. At the heart of the fridge is something called refrigerant.
If you want to skip the wall of text, this video does a pretty good job of explaining the basics:
Imagine a boiling kettle. A kettle adds heat energy to water, eventually turning the liquid water into a gas: steam. The refrigerant is another chemical (historically, freon was used) that is liquid at very cold temperatures and a gas at room temperature.
All of this refrigerant is stored in a system of pipes and tubes. At the core of this loop is something called a compressor. The compressor pressurizes the gas until it becomes liquid. The liquid refrigerant then leaves the compressor into the evaporator tube. This evaporator is located inside the walls of your fridge. Just as water absorbs heat from the kettle when it boils, as the refrigerant turns back into a gas it sucks out all of the heat from your fridge. Warmed up coolant then flows down the evaporator tubes into the condenser, where it waits to be recompressed by the compressor.
This is the basic premise behind the fridge if your home. But all of these fridges run off 120V alternating current. Compressors require a LOT of energy to run. If you tried to run this directly off of your car battery with a little inverter, your battery would die in a matter of minutes. For this very reason, manufacturers had to get really creative when designing a cooler that could run off low voltage DC energy.
When it comes to keeping your food cool while on the go, you have three different options. Each of these options has their own sets of pros and cons. We’ll go through each type of cooler one by one and help you find the type that’s right for you. Afterward, we’ll show you our favorite models in every category.
Option 2: Thermoelectric 12V Cooler
This is generally the first option that people look at. There are three main benefits to a thermoelectric cooler:
These types of coolers are cheap enough that they could be considered a reasonable impulse buy. Generally priced in the low three figures (with some even cheaper models!) many consumers just decide to try it out before investing hundreds in a high-end model. They look a lot more like your standard cooler, and are often sold as an upgrade to standard ice-fueled coolers.
They Plug Directly Into Your Cigarette Lighter
You don’t have to do any fancy wiring, and you don’t have to spend any time installing them. Just throw them into your vehicle of choice, slap the plug into a standard 12V outlet, and drive away. However there is ONE important thing to double check before you do this – make sure your car has battery protection. this means it will shut off power before the battery gets too low to start. If you don’t have battery protection, you might be left needing a jump start.
They Can Run Off a Standard Car Battery
Even though your standard car battery is 12 volts, not every 12V appliance will run off of it. Car batteries hold a lot of power, but something as simple as leaving your dome light on overnight can kill them. This is because starter batteries are designed for short bursts of high current output – exactly what’s required to start your car. Drawing small amounts of current over a long periods of time can leave your battery drained very quickly. This is why most 12 volt appliances require something called a “deep cycle” battery that is designed to be discharged for long periods of time. While this is generally a rule, with thermoelectric coolers you don’t need any special battery to run.
The downside of these coolers is that you can’t expect them to work like a fridge. Refridgerators run off of compressors, but 12-volt coolers use something called Peltier cubes.
When current runs through two dissimilar metals, the heat is removed from one and then pulled into the other. This cooler is packed with tiny little cubes that wrap around the inside of the cooler, behind the insulation. Only a very small amount of current is needed, and an impenetrable wall of chilly metal keeps your cooler from warming up. To put it simply, this is basically a bunch if tiny metal cubes inside of a cooler. When you plug it in, they get chilly.
In the real world, most cheap 12 volt coolers aren’t worth their weight in salt. Models skimp out on peltiers (which can be expensive!) and you’re left with something that doesn’t work any better than a standard ice-filled cooler. However, there are still a few models that make suitable refrigerators for cars.
The Koolatron P75 is well reviewed and reasonably priced. In the short term, it can work really well. This would be the ideal choice for a weekend camping trip, or a few days out at the lake. You do have to treat it like a cooler. It needs ice, and it needs to be plugged in. The power simply helps the ice last longer. A standard cooler that might only keep your food cool for 6 hours could get 12 hours of a peltier cooler. Check out buyer read the reviews on amazon to see how people made it work for their situation.
This cooler is suitable for anyone who needs to keep their food cold for about 12 to 24 hours. Basically, it doubles the life of your ice. Plus, since it uses very little electricity, you can run it directly off your cigarette lighter. This makes it great for days down at the beach, or a quick fishing trip.
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Option 3: 12V Car Refrigerator
If you want your food to stay cold for 24 hours or more, you’ll want to spend the money on something that works. When properly set up, These fridges run just as well as the ones in your home.
The main advantage is the efficiency. They’ll typically consumer around 10 amp hours per day, on a 12V system. This means that a standard deep cycle battery can keep this running for five days. If you have an RV with a solar system, you can keep it running indefinitely and stay completely off grid. However, there is just one thing you want to make sure of:
|Important: Make Sure You Have The Right Battery Type
With all that said, there is one important technical detail we have to talk about here. And that is battery type. All battery capacities are measured in amp hours. So in theory, if you had a 100 amp hour battery you could run something that draws 10 amps for 10 hours, or something that draws 100 amps for one hour before the battery is flat. But in the real world, it doesn’t work this way. Batteries are designed to do either high current for a short amount of time, OR they can do low current for a long time. The starter battery in your car for example, probably has around 110 amp hours. However it is designed to push out 800+ amps for a few seconds while starting your car. If you leave the interior light on, it might only draw one amp but 10 hours later your starter battery is flat. You only used 10 amp hours on a battery rated for 110 amp hours, but you drained it because low discharge is not what it was designed for.
These brands of car refrigerators are designed to be used on low discharge systems. Ideally, you will have two batteries. One to start your car, and a special deep cycle battery from a store that sells RV parts or solar gear to run your fridge and any other camping equipment you can have. That will work best. You can get starter batteries that are rated for deep cycle capacity, but these are pretty middle of the range. They are an okay starter battery and they are an okay deep cycle battery, but they aren’t great.
What’s unique about these refrigerators is that they use special compressors that are designed from the ground up to be run on 12V DC electricity. The current king of 12V refrigerators is the anything made by Dometic. They’ve produced refrigerators for a long time, and they also produce their own refrigerators compressor. So they use less power, and are well insulated enough to keep keet in.
Compare that to your typical mini refrigerator which draws about 20 amps at 12V, more or less continually. That’s not very energy effecient! And we don’t mean that the compressor is continually running, but you’ll almost wish it had! When refrigerators start there is a huge inrush of current as the compressor starts to turn and compress the refrigerant to it’s cooling temperature. In fact, these refrigerators use more power in the first 10 seconds of starting than they do in the next 10 minutes of running! And these mini bar refrigerators are designed to be cheap to make, compact, and still hold one or two items. So the first thing they skimp on is the insulation. So that means the refrigerator is constantly warming up, turning on, turning back off, then turning on again. In some cases, a mini fridge uses the SAME amount of power as a full size home refrigerator. And insulation has a LOT to do with it.
Dometic, as well as other respectable manufacturers of 12 volt refrigerators, takle this power problem two ways. First is insulation. Insulation makes the cooler bulky, it costs more to produce and gives you less room. But it stays darn cold for a long time and is very energy effecient. So that refrigerator’s compressor only has to kick on once in a while. Most of the time, it’s just sitting idle. Additionally, most 12v refrigerators have a higher temperature “deadband.” The deadband is essentially the ‘wiggle room’ with the temperature.
If it’s set to stay at 40 degrees Farenheit, a home refrigerator might turn on the cooling once it warms up to 41.5, and turn it off when it hits 38.5. You’ve got a three-degree deadband.
(If you didn’t have this, your fridge would constantly be turning on and off as it went from 40.00 degrees to 40.02 degrees and back down.)
Since 12 volt car fridges want to start the compressor as little as possible they will have a larger deadband. Now, you don’t want your food to spoil. So a respectable brand might cool all the way to 35 Farenheit then warm back up to the setpoint of 40. But we’ve seen some poor models that can be plus or minus 6 degrees above or below the setpoint. With a 12 degree temperature fluctuation your food won’t last as long, so it’s important refrigerator manufactures balance functionality with power consumption.
The ARB 12V refrigerator has an energy efficient low turnover compressor. It doesn’t require any high current surges to start, and the total current draw is only 0.87 amps per hour.
You can run it for five days on a single deep cycle battery without charging it. If you want to make it last longer, you can pop up a single 50W solar panel or drive your vehicle for 10 minutes to get enough charge to run the fridge for the entire day.
In terms of functionality, the ARB fridge is the ideal solution. The issue, for most people, is the price. It’s not easy to find locally, and most vendors charge a pretty high markup. If you’ve got cash to burn, check out a boating store. Sail boaters often use these fridges. If you’re willing to ship it, Amazon usually has it in stock. If you’re lucky, you can catch them on sale from time to time.
Although expensive, the design makes it clear that you’re getting your money’s worth. No other fridge on the market is anywhere near this effecient. This is a chest style fridge, it opens from the top. When you open the door of a standard front facing fridge, all the cold air falls out and the compressor has to start. When you open this one, it remains cold.
It’s 50-quart capacity means that it can hold 72 beers, or a heck of a lot of food. For longer storage of frozen goods, you can drop the temperature down to -1 degree Celsius for a true RV freezer.
These units are designed to take a beating. Did you know that you can damage a regular fridge by laying it down? The same is true for portable models. But the ARB 12v refrigerator is designed to be bounced around, making it the perfect companion to any RV.
ARB fridges are the best option for anyone who needs a long term food-storage solution. It’s a popular choice among overlanders, vandwellers, or RV enthusiasts. ARB fridges are also found in off-grid applications with solar installations. If your needs are a little more simple, it still makes a great camping fridge!
If you need a cheaper option, consider a Whynter fridge. These units have dual compartments so you get both a fridge and a freezer. They’re quite durable, although they take a little more space than an ARB model. Some consumers have found that they aren’t quite as power efficient, although the difference is really negligible when you consider the amazing cost-savings.
One of the things we really liked about the Whynter option is just how well the freezer works. It’s even cold enough to make ice cubes! Whether you’re looking for a way to store your catches on a fishing expedition, or just want to have some meat on hand for your next camping trip, this unit is well worth the investment for any serious outdoorsman.
Option 3: Diy 12 volt refrigerator
We’ve looked at the best 12V refrigerator that you can buy off the shelf, and we’ve also seen a few items that are more form than function. If you want to go with a pre-manufactured refrigerator it’s certainly one of the easiest ways to get a fridge in your RV. But if you’re reading shedheads, you’re likely the type of person who isn’t afraid of a little DIY. And if you can sacrifice a little space and time, I can show you how to build a fridge that will be MORE energy effecient than ANY home refrigerator or RV 12 volt fridge on the market. Best of all, this unit is made from easy to assemble items that you can find locally or on amazon.
Remember, what made the top brands fridge great was the fact that it was well insulted, so the compressor didn’t have to run much to keep the refrigerator temperature at an acceptable rate. This is called a light duty cycle, so it will be off most of the time. But there are actually two things that make a great power effecient refrigerator, and it’s easy to overlook. Almost every portable fridge is top loaded.
Hot air rises, right? When you open the fridge door, warm air moves up into the fridge and the cool air falls down to the floor, increasing the internal temperature. This means that the compressor has to kick on to keep the fridge cool, and therefore you’re using more power.
An apartment freezer is very similar to a portable fridge. And even the cheap brands are well insulated, otherwise, they wouldn’t work. This is because of the high differential temperature. If it’s 15 degrees outside and you only feel comfortable when it’s 60 degrees or warmer, you have to throw on some thick clothing to stay insulated! But in the fall, it might be a little nippy, but a long sleeve will do you just fine. And that’s because there is a lower temperature differential – the temperature it is outside vs the temperature you want to be.
It’s always winter inside a freezer. Just look at the fridge freezer you have in your home. The freezer walls are thick, but the fridge walls are thin. So just on that fact alone, a cheap apartment-sized deep freeze looks like the perfect design for a portable fridge.
There are, in fact, two good reasons that small freezers make great portable refrigerators. And that’s the duty cycle. If you read our primer on refrigeration, refrigerators have a compressor that squish refrigerant until it’s a liquid, then that icy liquid circulates inside the walls of your refrigerator to suck the heat out and evaporate back into a gas. Well, the compressor in a freezer has a MUCH harder job than the one in your refrigerator. It has to get a lot colder. And unlike refrigerators, where you want the temperature to stay within a few degrees, a freezer just has to stay frozen. An extra 5 degrees below freezing isn’t going to hurt anything. So this means that they run a long duty cycle. Remember that? Starting a compressor takes a LOT of power just in the first few seconds, so it’s much more energy-efficient to run a compressor for, say, 15 minutes every hour than it is to run for 7.5 minutes every half hour.
Compressing coolant to the point of reaching subzero temperatures is very challenging. If you ran these compressors all the time, they’d very quickly burn out. To correct this, manufacturers run them on a 25% duty cycle. Every hour, it’s only supposed to work for 15 minutes. So that’s great for battery life.
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The first step was to find a freezer that used very little current. This wasn’t easy, cause there are still companies Most manufacturers don’t publish the true power use, only their useless energy star ratings. After digging through a few that were drawing upwards of 3 amps (yikes!) we finally came across the Midea WHS-129C1. It was almost perfect. 3.5 cubic feet of space, a low foot print, and it only draws 1.1A while running! Plus, there is a two-year warranty on the compressor. These are the most common points of failure, and the fact that there was a warranty indicated to us that it was a reliable unit.
After ordering it, we opened the package and checked it out. It was nice and spacious, very well insulated for the price, and the compressor was rated for at least twice the duty cycle. After plugging it in, we ran it on a kill-a-watt meter for a few days. 1.5 kilowatts per day, not too shabby!
The next step is to turn it into a fridge. Basically, these freezers have little controllers in them. When the temperature is around -4, they shut off the compressor. It slowly warms up to 0, and the compressor kicks on again. Obviously, this won’t work for us. For a couple of bucks, we picked up the Inkbird Dual Stage Digital Temperature Controller.
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This handy little controller lets us control the temperature ourselves. You can buy dedicated fridge controllers, but these are usually sold at 10x the price. This is a more advanced device, and will let us do the exact same thing.
The first step is to wire it up. We removed the end from an extension cord to reveal the three wires. You’ve got a hot (red wire), and neutral (black wire), and a ground (green wire). Follow the diagram above to wire it up.
The first thing you’ll connect is your hot lead. Take the red wire and connect it to pin 1, and connect the black wire to pin 2. You are now going to take a small length of wire and shove that into the connector for pin 1 along with your hot lead, then connect the other side to pin 7. Your next jumper will connect from pin 2 to the neutral lead on your freezer. The next jumper goes from pin 8 to the hot lead on your fridge. Finally, you’ll want to connect the ground from the freezer to the ground on your extension cord.
Power on the controller and press the S button. Next to the “cool” value select the number 4, and next to the heat select 0. Finally, turn the setting knob on the freezer to the highest value.
This might seem complicated at first, but it’s very simple. The controller stands between your freezer and the power source. When the freezer is on, it wants to get as cold as possible as fast as possible. The temperature controller has a long cord with a thermometer inside of it. You drop that in the freezer and close the lid. If the temperature inside is four degrees or above, the power is turned on. Once the temperature hit’s 0, the 12V refrigerator is turned off. Now you’ve got a fridge.
Remember, the duty cycle of the compressor was 15 minutes. But that was to freeze it. With our controller in line, it only runs for about 6 minutes per hour. At 12V DC, the compressor draws 10 amps. Since it only runs for 1/10th of an hour, we’re using 24 amp hours per day. Your 100 AH deep cycle battery can run this fridge for almost 4 days without a single recharge, comparable to the ARB.
The last thing you’ll need is an inverter. Both the temperature controller and the fridge itself sit on the 120V side of the circuit. What an inverter does is convert your 12V DC electrical source into a 120V AC source. There is, however, one big catch with the inverter. If the fridge only draws 10 amps, then in theory you’ll only need a 120 watt inverter. But there is a very brief moment where the inverter pulls a very high amperage when the compressor first starts to turn over, for that reason, we recommend getting a 500 watt inverter minimum, or 1000 watt if you want to run other things on the circuit.
Overall, this is a very affordable way to get a 12V refrigerator. But if you’re willing to spend a little extra, you can get a very professional finish that performs a little better than the DIY option.