Many of those small "ceramic" heaters need 1500W. That means you would need a big inverter that connects directly to the battery. Every power inverter has a power rating in watts. The typical inverter intended for use in power outlet (lighter socket) is 200-400 watts. That's enough to power electronics and lighting, not power tools or heating devices. A hair dryer requires 1000 watt power inverter.
Car inverter is an electronic device that takes a DC input and converts it into an AC output. Since car batteries provide DC voltage, and most consumer electronics work on AC, inverters are useful for using laptops and other devices on the road. However, there are some vital constraints to keep in mind whenever you use an inverter in your car. Factors like the capacity of the car battery, rated output of the alternator, and output wattage of the inverter can all play a part in determining which devices can be plugged in and used.
Power inverters for car can work in just
There is some truth to the frying the car's electrical statement. Depending on the load placed upon it, it may cause the alternator to run at full output, which most of them (at least from the factory), are not intended to do for more than a very short amount of time (typically less than a minute). A continuous high load condition can overheat the alternator, leading the failure.
A car power inverter will take the 12 volts DC from your car; usually from your cigarette lighter and turn it into 110 volts AC, which is what you get out of your home power outlets. This allows you to plug household electronics into your car. the most common would probably be your laptop. Home UPS systems do the same thing, except instead of using a car outlet they use a 12 volt battery. I used a old home UPS system I had laying around that had a bad battery.