Whether it's a weekend in the woods or a weeks-long road trip, you need a way to keep your food cold. When it comes down to true refrigeration—something that keeps your food from going bad without spending half of your travel budget on bags of ice—things can get a little confusing.
That’s not to say there aren’t plenty of options available. There are many. But that’s part of the problem; it’s difficult to determine which solutions actually work and which ones are nothing more than a glorified ice chest. There are inverters and portable fridges and RV fridges that run off of propane and even ones that plug into your cigarette lighter. Trying to make an informed decision is a nightmare.
In this guide, we’ll help you narrow things down by looking at how fridges work and examining the options you have available to you. With this information, you’ll be able to find a high-quality 12v fridge that’ll keep your food nice and cold without killing your batteries.
To understand what makes a good 12v fridge, it’s helpful to understand the basics of refrigeration. In most refrigeration systems, there are three important parts: A compressor, a chemical refrigerant and the tubing required for the refrigerant to travel through.
A refrigerant—typically freon—is the magic that makes good refrigeration possible. At room temperature, it’s a gas, but when the temperature drops, it turns to liquid. However, the temperature isn’t the only thing that causes this state change. Pressure does it too, and that’s where a compressor comes in.
A compressor pressurizes refrigerant which, in turn, causes the gas to heat up. Once it heats up, it turns to liquid. If you’ve ever put your hand on the side of a fridge and felt the warmth it produces, you felt the effects of a compressor turning a refrigerant from gas to liquid.
As the refrigerant turns to liquid, it moves through a network of pipes and tubes that run through the walls of the fridge. But it doesn’t remain in this liquid state. As it runs through the tubing, it cools down to ambient temperature, which causes it to change back into a gas state. And as it does so, it literally sucks the warmth out of the surrounding area. In other words, a refrigerator isn’t really cooling the space within as much as it’s sucking the heat out of it. This is the premise behind most refrigeration systems, whether it’s the fridge in your kitchen or your home’s air conditioning unit.
As you might imagine, a compressor needs a lot of energy to do its work. The fridge in your home, for example, runs off of 120v alternating current. If you tried hooking your fridge up to your car battery with an inverter, you’d kill your battery in minutes. This brings us to the topic of batteries and power.
Battery and Power Sources
Batteries are measured in amp-hours. In theory, if you have a 100 amp hour battery, you could run a device that draws 10 amps for 10 hours. But that’s in theory, and in the real world, there’s a little more to it.
Batteries are designed to be optimized for two different uses. They either push out a very high current in a short amount of time or they push out a low current for an extended amount of time.
Take a car battery, for example. Most car batteries are rated between 50 and 100 amp-hours. But these kinds of batteries are meant to push a high output all at once—exactly what a starter needs to engage the motor. But if you leave your headlights on, your battery won’t last long at all, even though headlights only draw around 10 to 15 amps. A typical car battery isn’t designed for low discharge, so not every 12v appliance can run efficiently off of one.
Most 12v appliances require a deep cycle battery. These types of batteries are designed for low discharge, and they’re much better at powering appliances that need a steady, albeit low, power current.
Those that do serious traveling for extended periods of time also utilize solar panels. With the proper setup, such as deep cycle batteries and adequate solar panels, you can run a 12v refrigerator without any outside power or charging.
12v Refrigerator Types
As you can probably imagine by now, manufacturers have to get creative to come up with something that works well off of low energy. The result is that there are a lot of different options out there sold as 12v refrigerators, but they aren’t all created equal. Let’s take a look.
Electrically Assisted Cooler
Electrically assisted coolers are the aforementioned glorified ice chests. They work by using a small current of electricity to help keep your ice frozen.
These kinds of coolers are extremely affordable, but they aren’t very effective. Put simply, they take the heat that’s inside your cooler and put it on the outside. There’s no actual refrigeration. Moreover, they also take a considerable amount of power to accomplish what equates to keeping your ice frozen a little while longer.
If all you ever do is the occasional weekend or Sunday afternoon out at the lake, and you don’t want to spend too much money, these are good solutions. But if you need actual refrigeration, stay away from them.
Thermoelectric 12v Cooler
Thermoelectric coolers are another relatively affordable alternative to true 12v fridges. And while they’re more efficient at keeping food cool than an electrically assisted cooler, they won’t keep your ice frozen.
These types of coolers use Peltier technology to keep things cool. It works like this: When you run an electrical current through two dissimilar metals, heat is transferred from one to the other. Like with a compressor and gas refrigerant, heat is removed from the surrounding area, cooling the interior. A 12v thermoelectric cooler’s walls are filled with tiny Peltier cubes that prevent the interior of your cooler from warming up.
While the idea is sound, it’s not going to do much in terms of keeping anything cold for an extended amount of time. You’ll give your food a much longer lifespan, but it’s not suitable for keeping anything frozen on long-distance trips.
Moreover, many of these coolers aren’t very well constructed. Peltier technology requires expensive metals to work optimally, and a lot of manufacturers skimp on these, resulting in little more than another glorified ice chest. That said, there are a few models out there that offer a suitable solution for keeping your beer cold for short excursions and weekend trips.
12v Compression Fridge
In most instances, a proper 12v compression refrigerator is the best bet in terms of power efficiency and chilling abilities. Of course, while they aren’t going to be as expensive as the fridge in your kitchen, they’re still pricier than the other alternatives here.
That said, a good portable compression fridge is going to hit all the right points for your travel refrigeration needs. For starters, they’re incredibly efficient. Many of these systems are designed and engineered from the ground up to run on 12v electricity, so they have features like power protection modes that prevent your battery from draining or dual-zone chambers for freezing and chilling to save power further. In fact, they’re efficient enough that, with the proper solar panel set up, you could run one indefinitely.
Another thing to consider is how well you can lug it around. Many portable fridge options aren’t made with this in mind, or if they are, it’s minimal at best. Good compression fridges have adequate handles and good, sturdy wheels for transporting and moving it around.
There are also certain uncertainties you have to plan for with your portable fridge, such as the fact that you’re lugging around, in and out of your vehicle, in the great outdoors. You’ll want something that’s designed to take a beating while you’re out there, and a good compression fridge is built with this in mind.
A well-designed compression fridge is made for portability, ruggedness, efficiency and effective cooling, and that makes them all well worth the extra cost. Given the fact that they’re the only real option for keeping things frozen, they’re the only real option for those looking for a solution to any kind of long-term travel.
The Bottom Line
There are a ton of options out there that run the gamut of effectiveness and efficiency. With that said, a traditional compression fridge is leaps and bounds better than any other kind of tech being used on the market today. The right fridge will run just as well as the one in your home at a fraction of the power. If you want to keep your food nice and cold and your ice frozen on long trips, you’ll want to invest in a true 12v refrigerator.