A power inverter is an device that converts low voltage DC (direct current) battery power to 115 volt AC (alternating current) common household power. Power inverters generally have between one and three outlets, allowing you to use your car's battery to power small appliances, electrical equipment, tools or even a laptop computer. All power inverters are not the same however, and you should have a good idea of what you will be plugging in and how much you will be using it before you decide to purchase one. Also consider how much you use your laptop on the road, since you have a choice of a temporary or permanent power inverter in your vehicle.

Choosing a power inverter for your laptop computer isn't simply a matter of plug and play, you need to know what the manufacturer's specs are for your laptop's power requirement. Once you have that information, find a power inverter that provides a minimum of 20% more power than your laptop requires. Also make sure the inverter is rated to provide continuous power, as some inverters are made to shut down when overheated. Again, keep in mind if you will need to plug in any other appliances or electronics when your laptop is plugged into the inverter, because you may require much more than the minimum amount of power.

When shopping for a power inverter, consider whether you will be using it frequently in a vehicle. If this is the case, you might choose an inverter that is hard wired to the vehicle's battery. If you are not sure you will need a permanent installation, you can easily find temporary ones that plug into the cigarette lighter outlet of your vehicle. A good rule of thumb is if you are going to draw more than 150 watts of power, it's better to go with a direct connection to the battery. Keep track of your usage of the laptop and make sure you run your engine regularly to recharge the battery. Most laptops can run 3-4 hours before charging is necessary.