Can You Use A Space Heater In Your Car? (We Find Out)

It is getting to be winter, and you may be dreading this. One of the reasons you may hate it is that your car does not have a central heating system anymore. This may leave you feeling cold and frustrated as you trudge through the snow in your cold car.

Another reason you may want it in your vehicle is because you wish to use this as an alternative to garage your vehicle instead, or you may be living in the car and want to learn how better to warm yourself during these colds, hard months.

Keeping that in mind, can you use a space heater within your car?

Technically speaking, you CAN use a space heater designed for residential areas in your vehicle with a converter. Still, it will be much safer and efficient if you use a 12V heater than a 120V heater in your car charger.

Plus, the car battery in itself would not be a suitable candidate for keeping a space heater charged up, as this will drain its life much quicker than expected. 

It is important to note how you can do this without a space heater when heating your car. Are there any alternative methods and ways you can do this without an average space heater?

We will be going over this and the best car heaters below, so keep reading to find out everything on this subject.  

Is It Safe To Use A Space Heater In A Car?

One of the many things you will always go over in life is your and others’ safety. This is to make sure you do not hurt yourself or others around you.

However, it is not 100% safe OR efficient to use a residential space heater within your car. There are quite a few reasons why this is—one being that your car battery will begin to drain much faster.

Reason 1: Car Battery Issues

A standardized car battery has 600 watt-hours of charge, which means that if you were to run a 200-watt heater for your car, it would last roughly 3 hours before needing to be charged again.

Even so, the car battery in itself will more than likely get around 50 charges until it no longer works also.

Reasons 2 & 3: Efficiency & Safety

The second reason is efficiency as well as safety. We already know the safety part, but being efficient is key to keeping warm.

If your car battery runs out within those 3 hours, how will you then stay heated for the remaining hours that you will be in your car? This is especially true if you are traveling.

Some people may not need that amount of time and may think they will get by with just a 10-minute drive here and there, but realistically, the time and energy it will take to jump your car are not worth it in the long haul. 

How To Keep Yourself Warm In A Car Without Heat

Since it is not wise to use a portable space heater within your car, the question now is, how CAN you keep yourself warm in the car without heat? There are many ways you can do this, so let us go over them:

Insulate Your Car

Insulation can do a wide variety of things. First, it increases energy efficiency. If you have a car you want to keep warm during winter, try to insulate both your car and garage for better warmth. There are many ways to protect your automobile:

1. Use A Tension Rod & Makeshift Curtains

Blankets are thrown over the rod and clipped to it by clips or clothespins.

Hang your curtains in front of all of your windows, but bear in mind that you will not be able to see any cars or people coming to and from your vehicle, so this may not be the best option.

2. Insulate Your Car With Cardboard

Essentially, cardboard acts as a form of insulation and allows your space to maintain temperature for a more extended time because of its air pockets between the two layers, which slows the heat transfer from one side to the other.

3. DIY Insulation

Make sure to get every crevice and corner, especially places in the car that cause a drought system that is completely covered up. 

  • Use Reflectix: This insulated is coated with aluminum and polyethylene. It comes in a roll, so it is reasonably easy to go over each window, use a sharpie to measure each window out, including the windshield, then cut your makeshift lines out. It is essential to count them twice BEFORE cutting; that way, you get a more accurate display. 
  • Insulating your seats: With all that padding in car seats, your chairs are not insulated one bit. All you will need is a lightweight camping mattress or pad.
  • Go the extra mile: If you KNOW how to take your car apart and put it back together, then another viable option is to use Noico RED.

    This insulates your vehicle better, as this foam is a closed-cell polyethylene self-adhesive foam. You will want to consider using this on the floors, doors, and possibly the roof.

Get A Space Blanket

Aside from insulation, having a space blanket that goes alongside this is another viable option, which is relatively inexpensive. Many sleeping bags like this are called a “zero-degree sleeping bag,” which overall reflects your body heat at you.

Retain Heat Throughout The Day

Retaining heat throughout the day can quickly be done by storing any form of heat when the sun is strongest.

If you are cooking or have a fire outside, heat some bricks and take them in the car for the night, which can help your car remain warm throughout the day.

Just make sure to put something the bricks can go underneath, like a towel or cardboard layer, so the seats do not get ruined in your car.

Why Don’t Car Companies Put Space Heaters in Vehicles?

One might ask themselves why car companies do not put space heaters in vehicles. Since we ALL know that cars will essentially become relatively cold, wouldn’t it make more sense to do just that?

Since space heaters use a lot of electricity, putting a space heater in an automobile would not be the wisest choice.

Not only that, but many cars nowadays come with heated seating and have electric heaters. Once the engine is at operating temperature, heat will be transferred over to the passengers when the coolant is free. 

So, Why Are They Not Insulated?

This is an excellent question to have. We talked briefly about how you can better insulate your car, but why are they NOT protected?

Since vehicles are not made home, it makes much more sense why they do not insulate the cars.

Realistically, it would be a waste of money to do this on their part because cars are meant to be driven around in a relatively short amount of time (even if it were a road trip) as opposed to being lived in.

Of course, some people tend to live in their cars or spend most of their time there. If this were the case, it is best to learn how to insulate the vehicle properly.

Residential Space Heaters vs. 12-Volt Electric Car Heaters

So what is the difference between a residential space heater and a 12-volt car heater, you may ask? There are actually quite a few differences, so let us go over each one of them.

1. Residential Heaters Are More Effective Than 12-Volt Heaters

It is no wonder people wish to get a residential space heater for their cars! It is a relatively much better option overall, as electric car heaters are not very popular.

However, a space heater is to run on AC power, which means it runs on a 120V AC (up to 1800 watts of power) instead of a 12V DC (up to 180 watts of energy), which is what a car space heater goes by.

This can fluctuate up and down depending on what battery charge level or what the system can handle. 

2. Residential Heaters Uses AC Power

On top of that, when you use a residential space heater, you would need to plug it into an inverter because it converts DC power into the AC power that the heat requires.

However, some space heaters are designed specifically to be used as electric car heaters. In that case, you are going to look for it being run on DC instead of AC.

If that were the case, then you do not need an inverter, but so that you know, these specific heaters tend to provide little heat if this is the route you wish to take.

If you yearn to find a powerful 12V car heater, it will require a direct connection to the battery in itself due to how much electricity they draw out.

3. 12-Volt Heaters Will Not Drain Your Car Battery

As we mentioned before, using a 120V space heater will drain the battery quickly rather than going through something much smaller, which is where our 12-volt car heater comes into play.

4. Residential Heaters Will Warm Your Car Quickly

Lastly, when you need to warm your car up before a cold morning commute, using a 120V space heater may be the better option.

However, newer car models are coming out with an automatic starting system, so it may be best to start the car up for 5-10 minutes before leaving instead of going through this hassle.  

Generally speaking, it is much less of a nuisance and less dangerous to use a 12V space heater than a 120V heater through an inverter.

We will be going over the best options for you to choose from for a heating system for your car, especially if you do not wish to insulate your automobile. 

What Are Some Of The Best Car Heaters?

Just know that when it comes to a 12-volt car heater, it may seem as if it will not heat the car in its entirety. This is because they are not supposed to heat the vehicle thoroughly but only HELP it heat up.

Given that, most car heaters only produce 150-180 watts of heat. In some cases, it may not help the car heat up faster due to your location.

Some space heaters are suitable for 30+ degree weather, where others are good no matter the climate.

That being said, here are some of the best car heaters for your car. We have done extensive research for you and read many reviews from other users, so this list goes from first to last on what we believe are the best.

Wagan HealthMateGood for body onlyYesEasy
Happybuy 8KW Diesel8KWYesModerate
Nessagro RoadPro300-wattsYesModerate
Funwill Car Heater150-wattsYesEasy
ROYADVE 12V180-wattsYesEasy
STYCC Car HeaterLow (unspecified watts)YesEasy

1. Wagan HealthMate

Although this is not necessarily a space heater, it will do wonders to keep you warm in the seat of your car itself. Wagan HealthMate heated seat cushion can warm up to 114-degrees.

All you would need to do is plug it into a 12-volt DC outlet. There is no auto shut-off or on, so make sure you manually plug it out unless you want the car battery to drain.

Some users have mentioned that this product is only okay and works slightly, whereas many others say it is excellent and works very well.

2. Happybuy 8KW Diesel 

Being one of the best space heaters out there for your car, it does come at $142.

However, this car heater is environmentally friendly and produces low fuel and power consumption, so it should last you for a longer time than others out there.

Although this product has many things that come with it, they mention how the heater is an easy installation. 

Although many users are relatively happy with Happybuy, there are also a few complaints, including mentioning how it runs like a 2KW instead of 8KW, but it still works relatively well in terms of heat.

Another common thing in reviews is that users say the glow plug has failed, but after a replacement, it works well. One of the things the manufacturers can work on is getting a better glow plug for their product.

3. Nessagro RoadPro 

This little heater has mixed reviews, with many saying it is good and others saying it is not worth the money. However, Nessagro RoadPro is a ceramic heater with a 25 amp power rating and 300-watts of heating.

Not only that, but this heater comes with a 30-day warranty, so if it is not something you are looking for, look to see if you can return it. The wire in itself is a 12-gauge 15′ wire and is an easy installation.

4. Funwill Car Heater 

Having a 3-in-1 function in heating, cooling, and air purification, you really cannot go wrong with this heater. Not only that, but you can use Funwill year around because of this feature.

This little heater has a 360-degree rotation and can defrost your windows quickly. Out of all the reviews, most customers say it is either lukewarm air or runs just okay, so if you want a fairly inexpensive car heater, then this one is for you. 


ROYADVE is also used for a multi-functional purpose, with it being both a fan and heater. They advertise that it comes with fast heating, although buyers seem to stray.

On the other hand, this little heater is easy to install by plugging it into a cigarette lighter, so you have that going for you!

They mention that using this device combined with another charging mechanism may produce a lot of heat or wind, so make sure only to use the heater while in usage.

6. STYCC Car Heater

As it says in the description, this heater is used mainly as a defroster. Keep that in mind before purchasing. The explanation may be misleading because many people have mentioned it does relatively nothing to heat the car.

However, STYCC is another easy installation that comes with the convenience of being plugged into your cigarette lighter plug. It also comes with a pure copper cable wire, so it will not damage the battery or hot the wiring. 


To come to a complete summarization of what we have learned today, it is possible that you CAN use a space heater to heat your car, significantly since many car heaters do not help very much.

Still, they are not recommended due to the battery drainage your vehicle will have.

However, there are many better alternatives to help heat your car. These things include insulating the vehicle as a whole, which may require professional work, or using objects already heated up to help your automobile stay hot, such as a brick (but put a towel underneath, so it does not ruin the seating.) 

All in all, you can guarantee that your car can get heated up in no time with the tools we have given you above, so make sure you use this article as a future reference! 

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Hubert Miles

I've been conducting home inspections for 17 years. I'm a licensed Home Inspector, Certified Master Inspector (CMI), and FHA 203k Consultant. I started to help people better understand the home inspection process and answer questions about homeownership and home maintenance.
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