Cars come with powerful heaters that are designed to keep you warm in even the coldest of conditions, but what do you do when your car heater fails? Repairing a car heater can be prohibitively expensive, and 12-volt car heaters are relatively affordable, so it's only natural to wonder if you can get by with the less expensive option.
While 12-volt heaters aren't designed to replace factory car heaters, and they aren't capable of putting out the same level of heat, they can come in handy in a lot of situations. It's just important to understand what you're getting into so you can make an informed decision.
In order to select the right 12-volt car heater, there are a handful of easy questions that you can ask yourself. These questions will address how you plan to use the heater, which will allow you to effectively choose whether to buy a 12-volt plug-in car heater a larger, hard-wired unit, or whether a regular 120v space heater might do the trick.
Considering these important questions will also help you decide what type of heater to select, how much wattage that you’ll need to get the job done, and whether a real universal car heater replacement that taps into the cooling system is what you actually need.
When Will You Use the 12-Volt Heater?
The most important question that you need to answer is concerned with how, and when, you plan on using a 12-volt heater. There are three primary situations where you might use a 12-volt car heater, and each one calls for a slightly different solution.
For instance, a 12-volt car heater can be used to replace a malfunctioning factory heating system when the engine is running. However, a 12-volt heater isn’t the right choice for heating up a car when the engine isn’t running.
How will the heater be used?
Replacing a Malfunctioning Factory Heating System
If you only plan on using a 12-volt car heater when the engine in your vehicle is running, then you’re on the right track. Since the engine is running, you can safely run the heater without draining the battery.
This is the only feasible way to use a 12-volt heater in a car, and it is also the only way to use an electric car heater as a direct replacement for a malfunctioning factory heater system.
Unlike factory systems, which rely on hot coolant from the engine, a 12-volt heater will provide heat the moment you turn it on. However, it will also draw a great deal more power from the vehicle’s electrical system than a factory system that only requires electricity to run the blower motor. It's also important to remember that no 12-volt heater will provide the same amount of heat as your factory heater.
If you're looking for a replacement car heater that will provide the same level of heat as the factory heater, then you'll be more happy with a universal car heater replacement that taps the cooling system and replaces the factory heater. These systems provide far more heat than electric 12-volt heaters.
Running 12-Volt Car Heaters With the Engine Off
If you plan on using your heater to defrost the windshield or warm the car up with the engine off, then a 12-volt car heater probably isn’t going to be a very good idea. Unless you start the engine while the heater is running, the battery may be drained to the point where the engine won’t start.
In that case, a battery operated heater may do the trick for defrosting, and a plug-in car heater that runs on 120v will suit your purposes for warming up the vehicle.
For more information, check out our full guide to the best portable car heaters.
Are There Any Fire Hazards?
The next question to ask yourself has to do with the issue of fire hazards, which typically come in the form of combustible materials inside your car. Anything from loose papers to upholstery that isn’t flame retardant can constitute a fire hazard, so it’s important to consider the space that you’re working with before you select a 12-volt car heater.
Most 12-volt car heaters are designed to be used in tight quarters, unlike residential space heaters, but every car is different. Use common sense, and consult an expert if necessary.
If there aren’t any combustion hazards inside your car, or you can mount a heater a safe distance from any potential hazards, then you have more or less free reign over your choices.
You may be better off with an oil-filled heater if there are any lingering questions about combustion hazards. These heaters take longer to warm up, but the trade off is that they don’t create the same type of combustion hazards that you see with other types of heaters.
Radiative vs. Convective 12-Volt Car Heaters
The two main types of 12-volt car heaters are radiative and convective, and they each have their own strengths and drawbacks. Oil-filled heaters fall into the convective category, and they are the safest to use in cars, trucks, recreational vehicles, and other tightly confined spaces.
Convective heaters like oil-filled units transfer heat into the surrounding air, which then rises due to the fact that hot air is less dense than cold air. That causes cold air to rush in to fill the void, which in turn rises up and pulls in more cold air.
This cycle is referred to as convection, which is where the name of this type of heater comes from. Since convection relies on a closed volume of air, these heaters work well in vehicles that are sealed up.
Although oil-filled convective heaters are relatively safe to use in confined spaces, some convective heaters use heating elements that can pose combustion risks.
Radiative heaters also use heating elements, but they don’t warm up the air around themselves. Instead, these heating elements emit infrared radiation. When this infrared radiation hits a surface of an object, it causes that object to warm up.
That makes radiative heaters great at providing heat in poorly-insulated environments like cars, but it also means that they won’t actually warm up the air inside your car. Some radiative heaters are also dangerous to use in tightly confined spaces due to the combustion risks posed by their heating elements.
Warm your cab and your winter drives with the best portable car heater.
Written and Tested By:
Will Moore Will MooreWill has written for several major auto sites including Motor1 since 2020, logging hundreds of hours researching and testing products ranging from child car seats to torque wrenches. Will is also Certified by Safe Kids Worldwide as a Child Passenger Safety Technician (#T836339).
Reviewed By:
Charles NoyesMotor1 Reviews Team Take:
The best way to heat your vehicle is by using the onboard air conditioning system. However, fixing your broken heating system can easily cost upwards of $500. The best portable car heater may be your only alternative during a harsh winter.
In this guide, we recommend several car heater options that we’ve tested. We’ve found options for window defogging, seat warming, and cab warming. Some of these heaters can be used outside of the car as well and are especially helpful for camping and outdoor use.
In our search for the best portable car heaters on the market we wanted to consider heating power, convenience, and portability throughout our testing process. We measured each heater on a scale of 1.0 to 5.0 stars to evaluate each product.
We named the Mr. Heater Golf Cart Heater, TIKSCIENCE 12V Car Heater, Sunny Color 12V Seat Cushion, Mr. Heater Portable Buddy, and Mr. Heater Little Buddy as the best-rated portable car heaters on the market in 2024.
Brand/ModelCostOverall RatingAwardMr. Heater
Golf Cart Heater
$100
4.3
Best Overall
TIKSCIENCE
12V Car Heater
$20
4.0
Best Defroster
Sunny Color
12V Seat Cushion
$55
3.7
Best Heated Seat
Mr. Heater
Portable Buddy
$100
3.6
Best for Large Cabs
Mr. Heater
Little Buddy
$65
3.6
Also Consider
*Because cost data fluctuates, the prices in the table above are approximate values that our team regularly updates.
After looking at factors such as car heater portability, design, customer ratings, and prices, our product testing team ordered the portable car heaters that best met these standards. A team member tested each product in a sedan, taking note of how well the portable car heater heated the space, was easy to move, and conveniently designed. Each portable car heater was given a rating out of 5.0 stars based on these criteria.
Learn more about how we tested portable car heaters here.
This 4,000.0-BTU heater is designed for golf cart use but can also be used in a car. It includes a cup holder adapter to fit in a center console, as well as safety features like an oxygen depletion system and tip-over switch. Because the Mr. Heater Golf Cart Heater is propane-powered, you should only use this heater in a ventilated area, which means don’t use it in your car with the windows up.
You can see how the Mr. Heater performed in each of our testing categories below:
Review CategoryScore (Out of 5.0 Stars)Heating Power4.0Convenience4.0Portability5.0Overall Rating4.3If you’re driving on the highway, this won’t work as a portable heater since the incoming cold air will cancel out any warming effects. However, this heater is quite powerful and in a slow-moving or stationary car can keep you warm. It is much more powerful than any plug-in 12.0V portable car heater could be, which is why we’ve made it our top pick. Note that you will need a propane tank to use this heater (sold separately).
Below are the pros and cons of the Mr. Heater Golf Cart Heater:
Pros
Cons
The Golf Cart Heater is good for providing a lot of warmth, above what a 12.0V portable car heater could be expected to provide. It isn’t good for warming your car while driving on the highway, as it can only be safely operated with the windows down for proper ventilation. Because it’s so portable it’s also good to take camping or to carry with you to a worksite.
This portable car heater is very easy to use. Simply screw in the propane tank and hold down the ignition switch. Our propane tank didn’t fit very well into the cup holder attachment. This made the Golf Cart Heater unstable in our vehicle. However, with the proper-size tank, the heater would have been stable in our center console.
There is no thermostat or temperature control, but this unit heats quickly (about three minutes) and gets very warm. Because it is powered by propane, there’s a slight gas odor. Again, do not use this type of heater (gas-powered) in an unventilated vehicle.
Users like the Mr. Heater Golf Cart Heater because it is warm, lights quickly, and is stable even in moving vehicles. While designed specifically for golf carts, some users have used it in cars to satisfactory results. Most say that a single tank can last upward of six hours.
Some complain that the pilot light can take a few clicks to ignite. Others criticize the top-heavy design and say the cup holder doesn’t fit well. This may depend on your specific vehicle. Another common complaint is that there is no way to adjust the heat output (just a single setting).
The TIKSCIENCE heater is a small dash-mounted window defroster. It has holes for permanent mounting and uses a pure copper cable and a built-in fuse for automatic safety shut-off. This heater also has a fan mode that can be used to provide a cool breeze in the hotter months.
You can see how the TIKSCIENCE performed in each of our testing categories below:
Review CategoryScore (Out of 5.0 Stars)Heating Power3.0Convenience4.0Portability5.0Overall Rating4.0This portable heater is good for defogging your window or helping to defrost your window. It adds some heat and may help some if your car’s heater is broken, but shouldn’t be relied on as an interior car warmer. It can also blow cool air when your car gets too hot.
Below are the pros and cons of the TIKSCIENCE 12V Car Heater:
Pros
Cons
As a 12.0V device, the TIKSCIENCE does not put out a significant amount of warm air. However, it does generate enough heat to help warm and defog a windshield. If your car heater is broken, this can help with defrosting as well. The TIKSCIENCE does add some heat to the cabin, though not enough to warm drivers on the chilliest days.
The TIKSCIENCE defroster doesn’t have a lot of reviews on Amazon, and negative reviews focus on the low heat output provided by this device. However, the TIKSCIENCE heater is designed for defogging and defrosting. Bear in mind that no 12.0V heater is likely to provide significant warming power.
The Sunny Color seat cushion turns any vehicle seat into a heated seat. The velour cover attaches to your seat and can be warmed to three different settings. Not only can this cushion add some extra comfort to your car seat, but it can also help keep you toasty.
You can see how the Sunny Color performed in each of our testing categories below:
Review CategoryScore (Out of 5.0 Stars)Heating Power3.5Convenience4.5Portability3.0Overall Rating3.7If you’d rather not use a gas-powered heat source in your car, a seat warmer like the Sunny Color is probably your next best bet. You won’t find any 12.0V car heater able to warm you as well, except maybe for an electric blanket. This heater can act as a good supplement to your car’s heating system by working faster to get you warm on cold days. This is a cheaper alternative to installing heated seats.
Below are the pros and cons of the Sunny Color 12V Seat Cushion:
Pros
Cons
This seat cover installs easily and fits snugly. It didn’t bunch or tear during our test. It is also quite soft and comfortable – more comfortable than the factory cloth seats in our test vehicle. This cover works well just as a seat cushion. Even without turning it on, the material traps warmth (which could be a downside in the summer).
We found that the Sunny Color cushion warms quickly and to a significant degree. While it may not be able to fully supplement a broken air conditioning system, it does a pretty good job of keeping your backside toasty.
Many customers use these to supplement their car heater, as they can warm up faster than an air conditioning system. Users appreciate the low power draw and high heat output. Some comment on how well this stays attached, not moving around once installed.
Be sure to unplug the Sunny Color when your vehicle is parked, as some note that it will drain your battery if you keep it connected with the engine off. Another typical complaint is the cord location. It is on the right side of the seat, so if you use this in a passenger seat, you’ll need to drape the cord over your lap to reach the center console.
The final two selections for this list are not designed to be used in a moving vehicle. However, these are both warm, portable heaters with multiple safety features. As mentioned, a 12.0V heater is unlikely to output much heat. In especially cold locations and seasons, you’ll need something stronger.
You can see how the Mr. Heater Portable performed in each of our testing categories below:
Review CategoryScore (Out of 5.0 Stars)Heating Power5.0Convenience3.0Portability3.0Overall Rating3.6The Mr. Heater Portable Buddy throws a significant amount of heat. It is easy to handle and use, which is why we recommend it for larger cabs. Keep in mind that you won’t want to use this in a moving vehicle and only in a ventilated cab (windows cracked).
Below are the pros and cons of the Mr. Heater Portable Buddy:
Pros
Cons
This heater turns on fast and heats up very quickly. For a small car like our test vehicle, the heat is too much. If you’re sleeping in a large cab or truck, the Portable Buddy could get you through frigid evenings.
The Mr. Heater Portable Buddy would be good for those sleeping in larger vehicles. It isn’t a good option to use in a car while driving, or any small space. However, the high heat output and independent power source make it an option that will actually keep you warm and won’t wear down your car battery.
This is also a good pick for those going on a road trip who plan to camp. While it can work in a ventilated cab, the Portable Buddy is best used as an outdoor heater.
Some mention that they have used the Portable Buddy for car camping, and it works very well for that purpose. In general, users appreciate how easy it is to use and how much heat it’s able to produce.
A small number of reviewers say that their Portable Buddy stopped working after a few uses. While these comments are small in number, it does point to possible defects in some Mr. Heater products. This device is supposed to come with a one-year warranty, so contact the manufacturer should your Buddy stop working.
The Mr. Heater Little Buddy is something between the Golf Cart heater and the Portable Buddy. It isn’t designed for vehicle use like the Golf Cart heater and therefore is less stable. However, it offers more heating power than the Golf Cart heater but in a much smaller package than the Portable Buddy.
You can see how the Mr. Heater Little Buddy performed in each of our testing categories below:
Review CategoryScore (Out of 5.0 Stars)Heating Power4.0Convenience3.0Portability4.0Overall Rating3.6The Little Buddy is similar to the Portable Buddy in that you shouldn’t use it in a moving vehicle. This is a good pick for those planning to car camp or if you are going to sleep in your vehicle.
Below are the pros and cons of the Mr. Heater Little Buddy:
Pros
Cons
It’s not as large as the Little Buddy, but it lasts longer and may be a good pick for those with smaller cars that don’t want the full heat of the Little Buddy. The independent power supply means you don’t need to wear down your car’s battery.
The Little Buddy is very similar to the Golf Cart heater, with the two main differences being an increased heat output in a slightly larger package.
While easy to carry, there isn’t a great spot to put the Little Buddy in your car. We could put it in our vehicle’s cup holder, but it’s not exactly stable while driving. We don’t recommend using the Little Buddy in a moving vehicle.
Many reviewers have used this effectively for car camping and warming truck cabs in sub-zero weather. Most agree that it has a decent heat output, especially for its size. Some have used it in a moving car after securing it (though this is not something we recommend).
A few have mentioned that the Little Buddy works less well as it gets older. One user says it became impossible to start after a time. The most common complaint is that the Little Buddy can be difficult to light.
Frankly, the available options for heating a car are limited. Any heater that is powered through your car’s 12.0V outlet is unlikely to have enough power to combat freezing temperatures. Gas-powered portable heaters are much more powerful, but cannot safely be used in a car with the windows raised.
The best way to heat your cabin is always going to be your vehicle’s air conditioning system, but when these systems break, they can be costly to repair. If you lack the funds to repair your AC system, a portable car heater may be your only choice.
What To Consider
When looking for a portable car heater, consider how it will be used. Wired 12.0V electric car heaters can be used with the windows up, but aren’t very powerful. A propane heater can put out a lot of heat, but shouldn’t be used in an unventilated cabin. Driving with the windows down can bring in more cold air that the heater may be able to warm.
Some other alternatives to keep yourself warm in an unheated car are an electric blanket, a heated seat, or even an old-fashioned hot water bottle bag.
When it comes to dealing with cold weather inside a vehicle or camper, your best bet should be the vehicle’s heater fan. If your vehicle can’t adequately produce hot air, a 12V portable car heater might be a workable substitute.
We’d recommend using steering clear of propane or diesel heaters, since ventilation may not always be an option in winter weather. Ceramic heaters usually offer fast heating, and a power inverter for a lighter socket works as a plug adapter if needed. Still, customers should be wary of things like overheating with any portable electric car heater, and purchase items with modern shutoff safety features.
In this article, along with sharing helpful purchasing tips for those interested in purchasing a portable car heater, we reviewed the top five portable car heaters in 2024:
Still looking for the right portable heater? We haven’t had a chance to test the following recommendations, but they may also be a good option for those in need of some extra cabin warmth.
Cost: Around $100
This 12.0V heater will likely have some of the same issues as any other 12.0V heater: it won’t get especially warm. However, the Rampage can add a bit of heat to your back seat. It is mounted on a swivel bracket so that it can be easily positioned.
Cost: Around $250
This JEGS heater may not be specifically designed for a car, but it can offer a bit more heat than a typical 12.0V heater. Reviewers on Amazon have used it for tractors, boats, and trucks. This unit is costly and requires some skill to install. However, users seem to think it provides a decent heat output.
Cost: Around $40
One benefit of this defroster is that it can be used to both heat and cool. The design allows users to easily position this car heater. While not especially powerful, the output of this device is narrowly concentrated, so that you can keep your hands warm on the wheel.
Below are some common frequently asked questions about portable car heaters:
There are many portable heaters designed for cars. However, be wary of 12.0V car heaters, as this is not typically enough power to generate a significant amount of heat. Some portable heaters can be taken inside your car, though are not specifically designed for vehicle use.
Portable car heaters do not work nearly as well as your vehicle’s air conditioning system. Most 12.0V car heaters don’t throw a significant amount of heat and you may be better off with an electric blanket or heated seat cover.
However, a portable car heater can be useful to more quickly defrost your windshield or to add a little bit of heat in a pinch. Propane-powered heaters offer a lot more heat but cannot safely be used in a cab with the windows up.
We think that the Mr. Heater Little Buddy is the best option for a portable car heater. It’s small yet powerful. However, it has several drawbacks. Because it is gas-powered, you shouldn’t operate it inside your cab without ventilation (windows open). It’s also not easily stabilized in a moving vehicle, so it works well for situations where you may be parked but is not as good at heating your car while you’re driving.
You can warm your body with a hot water bottle bag or a good blanket. If you need to heat your entire car and not just yourself, there are portable car heaters that can raise the cabin temperature. However, these aren’t as good as a functioning air conditioning system.
Parking your car in the sun with the windows up can raise the temperature of your car pretty significantly as well.
You can use a propane heater in your car, but take care when doing so. You should never run a propane heater in a car without proper ventilation. This means do not use such a heater while the windows are up. It is often not a good idea to use a propane heater in a car while driving unless the heater is completely stabilized. Otherwise, you risk burns or worse. It is also inadvisable to run a propane heater in your car with the windows up while you sleep.
To test these heaters, we sat in the vehicle on a cold day, using nothing but the heater for warmth. Heating power, convenience, and portability are the most important factors we wanted to consider during our testing process to provide an honest evaluation of each product.
Heating Power: Our heating power score is based on the amount of heat each portable heater can generate, and how quickly it can get warm. Heaters that put out the most BTUs the quickest score best in this category.
Convenience: Not every one of our recommendations is specifically designed for use in a vehicle. Our convenience score is a representation of how well each heater integrates into the car. Does it have an easy place where it can rest or be stored? Can the heater be used while driving? Heaters that are well integrated into the vehicle and don’t require a fuel source score best in this category.
Portability: Heaters that are lightweight and easy to move score the best for portability. The inclusion of convenient carrying handles or storage options also contributes to a higher portability score.
How We Score Products
Star ratings help us to differentiate between products so we can honestly and accurately evaluate each portable car heater. We calculated an average rating of 3.8 out of 5.0 stars among the portable car heaters in this review.
Why Trust Motor1.com
Each year, we test over 350 auto products on vehicles and in our testing lab. Our team of product testers thoroughly researches top products, unboxes and puts our hands on each component, and tests the items on real vehicles before making recommendations to readers.
We publish hundreds of product and service reviews to bring car enthusiasts detailed guides on automotive tools, detailing kits, car seats, pet products, and much more. For more information on our testing methodology and how we evaluate every product, check out our methodology page here.
*Data accurate at time of publication. Products subject to availability.
Will MooreWill has written for several major auto sites including Motor1 since 2020, logging hundreds of hours researching and testing products ranging from child car seats to torque wrenches. Will is also Certified by Safe Kids Worldwide as a Child Passenger Safety Technician (#T836339).
Charles NoyesAs a member of both the APA and IMPA, Charles Noyes has devoted himself to creating and refining quality content covering automotive products and accessories, motorcycle products, RV products, and more. As the lead editor serving the product review team, he has personally reviewed, critiqued, and fact-checked over 200 product reviews.