DC to AC power inverters allow you to use devices in your automobile which normally plug into a 110V AC electrical outlet, by connecting them to the cigarette lighter. While some devices have DC power jacks and can be directly attached to the lighter with a power cord, a DC-to-AC power inverter eliminates the need for device-specific cords and allows devices which only have AC cords to be used, by converting the lighter socket into a standard three-prong outlet. Here are some tips on choosing the best power inverter for your purposes…
1. Determine how much wattage you will need to power the device(s) you are intending to use. Some electronics have their maximum wattage consumption printed on a bottom or rear panel, while others may list it in their instruction manuals. A “Kill-A-Watt” meter (available on Amazon.com for about $25) can be used to monitor how many watts a device is using. Be sure not to confuse this with voltage or amperage. Check the maximum wattage the DC-to-AC inverter is capable of supplying to determine if it is sufficient. For example, the Lenmar NVD-75 provides up to 75 watts, while the Whistler PI-200W can deliver 200 watts of continous power. Some models can provide a higher level of power for a limited period of time, or a continous lower wattage. Generally, the higher the maximum wattage, the more expensive the inverter will be.
2. The additional safety and convenience features offered by DC-to-AC power inverters vary significantly. Here is a list of the features included on some models…
POWER SWITCH: While some of the less expensive inverters must be unplugged when not being used, others have a switch for turning them on and off.
MULTIPLE OUTLETS: Some power inverters, such as the Lenmar NVD-175X, have a cigarette-lighter style DC outlet next to the AC outlet, allowing a device with a cigarette lighter cord to be powered without unplugging the inverter. Also, quite a few of the more expensive models have a 2nd three-prong AC outlet.
INDICATOR LIGHT: Many power inverters have an indicator light to remind you that they are operating, and/or to verify that the connected device can be powered by the inverter.
LOW-BATTERY DETECTION: Some inverters, such as the Xantrex XPower 75, will detect when your car battery is running low on energy, then automatically shut down and/or sound an alarm.
USB POWER: A few DC-to-AC inverters have USB ports so that devices which would normally be powered by a computer’s USB port can run on your cigarette lighter’s elecricity. Small fans, vacuum cleaners, lights, and other devices are available which can be powered by USB ports.
COOLING FAN: Many high-wattage inverters have a fan to keep them from overheating, including some Black & Decker models.
DIRECT BATTERY CONNECTION: A few of the more heavy-duty power inverters, like the Cobra CPI-450, have clips which allow them to either be directly attached to a car battery, or powered from a cigarette lighter through a regular DC cord.
OVERLOAD/OVERHEAT PROTECTION: Some power inverters are designed to shut off automatically if there is a power overload or they become overheated.
OUTLET COVERS: A few inverters include an outlet cover which can be placed on the electric socket when it is not in use, to prevent it from collecting debris. These can also be purchased separately as they would be for household electrical outlets.
DC CORD: Some inverters have a DC cord with the plug on the end of it, rather than a plug directly built into the inverter as many smaller models have. This allows the inverter to be placed elsewhere in the automobile and prevents it from getting in the way.
3. Don’t buy a more expensive unit than you need to. It is possible to spend $50, $100, or more on a power inverter of this type, but a $5-8 generic inverter from eBay may be sufficient if you only need to power a low-wattage device like a portable radio or small battery charger.
Overall, try to select a DC-to-AC inverter which meets your needs without exceeding them unnecessarily, and is both convenient and safe to use. Power inverters can be purchased at electronics stores like Radio Shack, Wal-Mart department stores, and some shopping websites. While most models are in the $15-50 range, some cost as little as $5 or as much as $500.
