Is It Safe To Use An Electric Heater In A Car? (Answered)

Using an electric space heater in your car is fairly safe as long as you use an inverter.

How much space should you have open for a space heater in your car? Can they cause a fire?

Keep reading to learn all you need to stay warm and safe!

Is It Really Safe To Use An Electric Heater In Your Car?

You can safely use a residential space heater in your car with proper care and adaptation. You should check to see if the charge matches your car before you plug in a space heater. Alternatively, only use space heaters which are designed to be used in vehicles as well as homes. 

AC electric heater 1200W-3000W-1800W
AC electric heater 1200W-3000W-1800W

Most household space heaters are not suited for use inside your car. Home space heaters run on AC power, which is incompatible with most car charging ports. Plugging an AC charge into a DC power source can cause the unit to short, spark, and possibly start a fire. 

AC and DC power differ significantly in how they travel through the socket and wire, they have different characteristics and specifications.

AC or alternating current gains its name from how electricity flows. Alternating current travels in a forward and backward direction. It is the preferred electrical power source for homes and offices. 

DC or direct current is named for how the electricity travels directly and evenly. DC doesn’t fluctuate in how it flows and is preferred for vehicles and other small electrical sources. 

While some argue that one is better than the other, the truth is they are different and serve different needs.

Plugging a DC device into an AC plug or vice-versa could short and fry the device. This is very risky. Misused appliances can get damaged or cause a fire when plugged into the incorrect power wattage.  

Space heaters are dangerous when misused and have several warnings against fires. 

Since car systems run on DC power, a household heater isn’t compatible. Ideally, you should only use car heaters with a car plug rather than a household space heater. 

Additionally, there’s an issue with the average household space heater’s voltage (typically 120V). This is far beyond the capacity of the car charging port and thus increases the dangers of using this type of space heater. 

However, you can use a household heater in the car if you use a car inverter. We’ll discuss these inverters further below, but using a heater properly in your vehicle is essential. 


Are Electric Heaters Compatible With Car Electric Power?

Household electric heaters are not compatible with car electrical power. Cars use direct current (DC) electricity, while household electric heaters use alternating current (AC). Space heaters are designed for home outlets and can cause fires if they aren’t correctly adapted. 

Household space heaters aren’t designed to be used in car outlets. Although there are ways to use them safely, we will first explore the better options. 

Portable car heaters are the best option to provide extra heat to your vehicle. These 12V space heaters suit the car’s cigarette lighter and DC power. They don’t use too much power, but they also don’t satisfy everyone with the heat they produce. 

At best, they can only produce 15-20 amps. This can help make the area more comfortable, but not to the degree that a household space heater can deliver. Therefore, these are the safest method but aren’t always the most effective. 

Alternatively, you could use an electric household space heater. However, these space heaters usually have a different voltage than the car. Additionally, they pose a higher fire risk when used in small spaces such as your car. 

The safest way to use a space heater is with an inverter. Car power inverters plug into the car’s battery. This will allow you to plug in a low-powered heater safely. 

This will prevent the heater from shorting or sparking due to inappropriate power surges. 

These heaters are supposed to be kept far away from flammable objects. When used inside a home, they must be kept away from materials such as curtains or tablecloths. However, this won’t prevent the heater from catching fire. 

This is very hard to achieve in the closed space of a car. You should not keep it on the floor between seats. The best place is on the passenger seat, which can also be risky. 

Never leave space heaters on and unattended. 

What Are The Different Types Of Portable Electric Heaters Made For Cars?

Portable car heaters designed for use in cars are the best option. However, there are several models which are better suited for different needs. Avoid leaving household space heaters and portable propane heaters inside your car unattended. 

Most space heaters that can be used inside a car fall into one of four categories: 

  • EV heaters
  • Portable propane heater/gas heater 
  • Household space heaters 
  • Portable car heaters

Standard EVs or electric vehicle heaters are designed to be plugged into the EV’s battery. These devices convert electrical power from the car battery into heat. These are the unique heating system for most electric cars and aren’t compatible with gas-powered cars. 

If you have an electric vehicle, be careful how you use the heater. The heater runs on battery power, which can drain the car’s battery more quickly than usual. 

Propane heaters are somewhat controversial. They’re not necessarily unusable inside a car but should be used cautiously. 

Propane heaters utilize oxygen and produce carbon monoxide. Carbon monoxide is toxic and dangerous since it has no scent or color. You could die if you turn on this machine and fall asleep with the windows closed. 

Most modern models have a sensor to shut off when oxygen levels become lower than advised. However, it can be risky to only rely on this sensor. If you use these machines, only run them while awake and have the car windows open. 

We already discussed the safest way to use space heaters in your car. However, there are several models which are better suited for your vehicle. These models include the following: 

  • Ceramic Tower 1500W Indoor Space Heater with Oscillation
  • Heater and Fan Combo with Remote, 
  • DesertWest Space Heater Indoor Use, Electric Ceramic Heaters
  • 1500W Portable Space Heaters for Indoor Use 

These space heaters are small and are safer than their bulkier counterparts. This will go a long way in preventing fires. 

Portable car heaters are the safest option.

The best portable car heaters include: 

  • Portable Car Heater, Plugin Defogger & Defroster, 
  • Portable Car Heater Mini Car Defroster Automobile Windscreen Fan 150W 12V
  • Car Heater 12V, 150W Portable Car Heater Defroster Fans
  • Car Heater 12V, 120W Portable Car Heater that Plugs into Cigarette Lighter

These portable car heaters have the best ratings and reviews. They’re noted for their capacity to warm the interior and defrost the windshield. This makes them comforting as well as practical. 

How Long Can A Car Battery Last With A Portable Electric Heater On?

High Amp Car battery with 12v and 110Ah
High Amp Car battery with 12v and 110Ah

Most car batteries can last 2.5-4 hours while powering a space heater. The time your car battery can last while powering a space heater depends on the type of heater you’re using. The quality and state of your car battery can also impact how long it can last powering a space heater. 

The space heater’s voltage can impact your car battery’s energy lifespan. While low-voltage heaters are the best option, they don’t produce as much heat as some may like. 

However, attempting to use a space heater with an inverter can impact power utilization. Most estimates state that inverters can lose 15-20% of power transmitting from the source to the device.  

As we explained above, these inverters are important for preventing shortages and fires. Therefore, this power loss might be something you need to accept. But you should consider this drag when calculating how long your battery will last. 

Plugging in a space heater to your car battery carries several risks, aside from being a fire hazard.

These risks include: 

  • Draws significant power 
  • Wastes energy 
  • Wears out the battery 
  • Could damage the battery 
  • Could damage the heater

You should minimize the amount of time you use the space heater. While car batteries are more potent than typical batteries, they can die when overused. Running a heater is similar to constantly starting your vehicle, which is unsuitable for your battery’s lifespan. 

Never leave your heater on overnight. The car battery charges when the car runs, so if your vehicle is off while the heater runs, the battery could die. You can prevent this by using your heater while driving or periodically turning on your car for an hour. 

If you’re sleeping in your car, there are better and safer ways to stay warm. 

How Can You Keep Your Car Warm Without a Heater? 

Pocket warmers are one of the best ways to stay warm in your car overnight. Properly insulate yourself and your vehicle, and place these warmers in your socks and jacket. Avoid placing them directly on your skin to prevent burns. 

If you’re in a pinch, there are several great ways to keep warm overnight in your car: 

  • Park your car in a garage or other enclosed space 
  • Cover your windshield
  • Insulate your car windows as best you can 
  • Utilize hand warmers 
  • Avoid alcohol 
  • Drink warm beverages
  • Wear insulated clothing 
  • Always keep emergency blankets and coats in your car

Keeping your car indoors or away from open spaces is an effective way to stay warm. Car windows aren’t the best at keeping out the cold. The more your car is exposed to the wind, the more cold wind drafts you’re likely to feel. 

If you don’t have access to a garage, park your car under a bridge or near buildings. This will help decrease the amount of draft on your car. 

Finally, always be prepared for the worst. Even though many of us keep a first aid kit with bandages, we forget to bring blankets and other warming devices. 

We recommend keeping at least two blankets in the back of your vehicle and two spare jackets. Keep hand warmers in your purse or bag whenever traveling long distances. 

You can also keep these in your glove compartment. However, be careful if the temperatures drop well below freezing. Hand warmers are made of water and other ingredients, which can impact their efficacy if they freeze. 

Never leave them on your car seat or in direct sunlight. They can catch fire. If you’re going to store them in your vehicle, keep them in your glove compartment or sealed trunk. 


Winter can be a harsh time for driving. The roadways are dangerous, and the insides of our cars feel like a freezer. 

We hope this article helped you find the best way to stay warm. There are safe ways to use heaters and warmers, but just follow the rules to stay safe!


LifeWire: Using a Space Heater as an Electric Car Heater

Power and Beyond: What’s the difference between AC and DC power?

Encyclopedia Britannica: alternating current

Energy Education: Direct current

LifeWire:  725 Understanding Car Power Inverters

LifeWire: Your Best Portable Car Heater Options

USA Today: 7 tips for safely using a space heater in your home

CNET: Best Car Power Inverter for 2022

Alex Wise: Electric Car Heater: How Does The Heater Work In An Electric Car?

Family Handyman: What to Know About Driving Your Electric Vehicle in Winter

Backpacking Light:  Advice on Propane Heater for Car Camping Tent

Minnesota Department of Health: Carbon Monoxide (CO) Poisoning in Your Home

Ceramic Tower 1500W Indoor Space Heater with Oscillation

Heater and Fan Combo with Remote, 

DesertWest Space Heater Indoor Use, Electric Ceramic Heaters

1500W Portable Space Heaters for Indoor Use 

Portable Car Heater, Plugin Defogger & Defroster, 

Portable Car Heater Mini Car Defroster Automobile Windscreen Fan 150W 12V

Car Heater 12V, 150W Portable Car Heater Defroster Fans,

Car Heater 12V, 120W Portable Car Heater that Plugs into Cigarette Lighter

Heater Tips: Can you run a Space Heater off a Car Battery?


Ready.Gov: Car Safety

USA Today: How to stay warm in your car during extreme winter weather