Do Cigarette Lighter Heaters Work?

What are cigarette lighter heaters and how do they work—if at all?

cigarette lighter heater windshield frozen
Cigarette lighter heaters are better at defrosting than they are at heating, and they're really better at demisting than anything else.

Jeff Schultz / Getty Images

Driving a cold car in the dead of winter isn't fun, and it can be dangerous if your windows are not adequately defrosted. One of the cheapest and easiest solutions is to plug a heater into you car's cigarette lighter socket. But do these niche contraptions actually work?

Do Portable Cigarette Lighter Heaters Work?

Cigarette lighter heaters are designed to convert energy from your car's electrical system into heated air. The problem is they can only draw so much power, so the resulting heat is paltry. That also means they cannot stand in for a standard vehicle heating system.

Car cigarette lighters are 12-volt outlets and most cigarette lighter heaters can deliver only around 150 watts of energy, which isn't much. Compare that to a common blow dryer, which usually blasts up to 2000 watts of heat.

In short, cigarette lighter heaters can produce heat, but not much and never in lieu of a traditional car heater. That makes them better suited for defrosting the windshield or warming up your hands.

Cigarette lighter heaters are too weak to stand in for a standard heating system.

Alternatives to Factory-Installed Heaters

If you’re looking for an alternative to your factory-installed heater, you should consider a 12-volt heater wired directly to the battery with an inline fuse. Another option is a residential space heater plugged into an inverter. Both of those options are limited by the amount of power that your car’s electrical system can put out.

If you’re just looking to warm your car up in the morning before a commute, then a basic space heater may do the trick. A battery-operated heater can also be effective if you merely want to defrost your windshield.

The only true replacement for a factory car heater is a universal heater that relies on coolant rather than an electric heating element, but they are far more expensive and difficult to install than any of these alternatives.

The Problem With Car Heaters and Cigarette Lighters

Cigarette lighter plugs are low in wattage. Most of these circuits are wired with 10- or 15-amp fuses. At 12 volts, even a 200-watt heater will draw over 16 amps, which is enough to pop most cigarette lighter circuits.

Any heater that includes a blower has to dedicate part of its wattage to the fan, which is why a lot of car heaters that plug into cigarette lighter sockets don’t have that feature.

Alternatives to Cigarette Lighter Heaters

Here are some workarounds if you don't want to rely on a cigarette light to heat your car.

None of these solutions can serve as a replacement for a factory-installed heater.

Wire a 12 Volt Heater into Its Own Circuit

This option requires you to connect a 12 volt heater to your car's electrical system.

What We Like
  • Use the right wire gauge for a high current power draw, and install an in-line fuse to properly protect the new circuit.

  • A 12 volt heater wired into its own circuit can put out far more heat than a cigarette lighter heater.

What We Don't Like
  • 12 volt car heaters, even those wired in this manner, still tend to be pretty weak.

Install an Inverter and Use a Residential Space Heater

This option requires you to wire an inverter directly to the battery, and then plug in a small space heater that's designed for use in your home. Even the smallest residential heater is capable of putting out more than enough heat for a car.

What We Like
  • Allows for use of more powerful heaters.

  • Residential space heaters can put out more heat than 12 volt heaters.

  • Can effectively replace a non-functioning car heater.

What We Don't Like
  • Residential space heaters consume a lot of power.

  • Your charging system may not be able to handle even a small space heater.

  • Most residential space heaters are dangerous to use in confined spaces due to fire hazards.

Either of these options can work if installed properly. Wiring a 12 volt heater into its own circuit is more efficient than using an inverter, but the wiring in an inverter is a more versatile solution since you’ll be able to use it for more than just an electric car heater.