Are you planning to go on a camping trip in the winter, and you want to know how to run an electric heater off a car battery in case the temperature becomes too cold? Or perhaps you’d like to be ready for a power outage during the cold months? You’ve come to the right place, for we have researched this question, and we have the answer for you.

To run an electric heater off a car battery, you will need a transformer, an inverter, and the car battery. Connect the electric heater to a transformer, then connect the transformer to the inverter, and connect the inverter to the car battery.

Let’s talk more about the different things that you will need to power your electric heater and how they work together in the succeeding sections. Learn more about how to supplement your car battery below.

Read on!

How to pick an electric heater?

Electric tent heaters are safer than propane gas or halogen heaters -especially if you're using it to warm a tent. They are also lightweight, and you don’t need to carry a separate propane tank to power your heater.

The only disadvantage of an electric tent heater is that it can consume large amounts of electricity. This means that you will need a way to supplement the power from your car battery at some point, but more on this later.

Before we talk about how to power your electric heater off your car battery, let’s briefly take a look at some tips on how to pick the best electric tent heater for your trip.

Portability

Getting a portable yet powerful electric heater means that you don’t have to give up a lot of space in your car when you’re packing, and you still get the right amount of heat for your tent. Keep in mind, however, that the ideal electric heater is not always the smallest. You may save a lot of space in your car but fail to get the right amount of heat that you need at camp.

It is important to strike a balance between an electric heater with a compact size and one that can produce the right amount of heat. Heaters that are not powerful enough will have to use additional energy to warm up your tent, wasting energy. If the heater is too powerful, your tent will become uncomfortable fast.

Here is a quick guide on how to determine the amount of heat that you need for your tent.

How to determine tent heater size?

1. Compute the total volume of space inside your tent. You can normally find this in the tent’s packaging or label.

• • If you don’t find this in the tent’s packaging, multiply the length, width, and height of the tent in feet.

2. Subtract the temperature forecast outside the tent from the ideal temperature that you want your electric heater to maintain.
3. Multiply the total tent volume by the temperature difference and multiply the result by 0.25. The result is the BTU of heat that the electric heater should produce hourly. The 0.25 is the insulation factor of tents.

Included Safety Features

The first safety feature is an auto shut-off function that turns off the electric heater when it becomes too hot. This is an important safety feature to prevent overheating. Overheating can cause the circuits to become too hot and possibly cause a fire.

The second important safety feature is an automatic shut-off function when the heater tips over.

Although many electric heaters are not too warm to touch, this is still an important feature for heaters. Flammable debris can get into the heater and might generate a spark that can start a fire.

And considering how uneven the floor inside a tent can be, this is a nice feature to have.

Blower Function

Some electronic heaters rely on radiant heat. The natural movement of warm air inside the tent will eventually spread the warmth of a radiant electronic heater.

However, this can take a long time, and in a really cold climate, you could end up losing the heat faster than it can spread inside your tent.

An electric heater with a blower spreads the heat faster to different corners of the tent. It’ll be the icing on the cake if it has a swivel function too.

Has A Thermostat

A heater with a thermostat allows you to set a temperature, and the electric heater will automatically shut down after it reaches the set temperature. This saves your car battery energy, which is an important resource when you rely on an electric heater for heating.

Amazon Basics 1500W Ceramic Heater is available on Amazon through this link.

Stability

Most electric heaters are stable—especially the ones made for use inside the tent. However, it is worth noting that this is an important attribute of heaters. Pick one that is the most stable to prevent tipping over.

Devices You Need To Power An Electric Heater Using A Car Battery

Once you pick up the right electric heater for your tent, the next step would be to prepare the devices that you need to power your heater. There are several devices that you will need, and we have all of them in a list below, including a brief description of what they do and why you need one.

Do I need a transformer to power a heater with a car battery?

A transformer is an electronic device that changes the voltage. It can increase the voltage or decrease it. The purpose of a transformer in your setup is to align the voltages.

Your electric heater uses 120 volts, while your car battery produces only 12 volts. So, you’d need a step-up transformer to convert the 12 volts from a car battery to the 120 volts that your electric heater needs.

It is important to note here that there are electric tent heaters that do not run at 120 volts. It is important to know the voltage that your electric heater needs before you pick up a transformer for it.

Do I need an inverter to power a heater with a car battery?

In addition to matching the voltage of the power supply (the car battery) and the device (the heater), you also need to align the type of electrical current of both. Car batteries produce DC electrical energy or direct current, while your electric heater requires AC electrical energy or an alternating current. This is why you need an inverter.

An inverter is an electronic device that converts the DC electrical energy from a power source like your car battery into AC electrical energy that your electric heater can use.

Modern inverters also function as transformers. This is a better option to reduce the number of devices that you need to bring with you. Moreover, this is also a cheaper option since you only need to pay for one device instead of two.

300W Power Inverter DC 12V to 110V AC is available on Amazon through this link.

How to connect a transformer/inverter to a car battery?

If you’re going to connect your heater to your car battery, you will need decent cables to run from your car to your tent. Ideally, you should connect the inverter/transformer to the car battery, then leave them inside your car.

Alternatively, you can connect them to the auxiliary power port inside your car. A word of caution about this is that most modern auxiliary power port doesn’t have robust wiring. Connecting an inverter/transformer to power an electric heater might trip the fuse.

So, you might be better off connecting the inverter and transformer directly to the car battery.

Once you have the inverter/transformer set up, connect a long heavy-duty power cable from inside your car going to your tent. The power cable should be robust enough to withstand the cold weather outside your tent. There are power cables that are made for outdoor use.

Alternatively, you can pick up an extension cord that is made for outdoor use to bridge the inverter inside your car and your electric heater. Your electric heater might have its own power cable, and all it needs is an extension to connect it to your inverter/transformer.

Southwire 100-Foot extension cord is available on Amazon through this link.

How to supplement your car battery?

Electric heaters consume a lot of electrical energy. This can quickly consume the charge of your car battery, and this can make it impossible for it to start your car unless you have a dedicated car battery for your heater that your alternator also charges.

However, for your car battery to constantly get a charge from your alternator, you need to leave your car running. This can consume a lot of fuel, and you might not have enough to last your trip unless you bring a lot of extra fuel.

Bringing extra fuel, however, is heavy and takes up a lot of space. An alternative is to bring a portable solar power station with you. The solar panels are foldable, making them easy to bring on a camping trip.

Moreover, some models include their own inverter/transformer. Thus, you don’t have to worry about using it to power your electric heater and other electronic devices in your camp.

OUPES 600W Portable Power Station, Solar Generator is available on Amazon through this link.

Conclusion

You will need an inverter and a transformer to convert the electrical power from your car battery to a type that can power your electric heater.

If you enjoyed reading this article, you might find the articles below equally enjoyable to read:

Do Electric Heaters Cause Condensation?

Will A 220 Baseboard Heater Run On 110?