I have been after one of these for a while, and since acquiring this one, I have never looked back. I can now use appliances which normally run on mains electricity, in my car. This is a positive (no pun intended) boon, and I am sure these will be fitted in all cars one day.
If you have ever used a laptop in a car, you will have had to get a twelve volt charging lead, to go with all the others you have needed, such as phone chargers, USB iPOD charger, etc. These are all adding to the collection of spagetti we accumulate in our cars. These inverters could be an answer to the problem. Instead of having to trawl through listings on eBay, or trudge through one shop or another, looking for the charger to fit your particular laptop, (which just happens to be the ultra rare one) you can simply use your mains lead.
Your car can be a mobile office, with a printer, scanner, and any number of low consumption electrics. You can charge up your rechargeable batteries for your camera, flashlight, or other appliances. I am talking about charging these up while on the move, meaning there is no chance of draining the car battery, and the bonus being "free electricity".
An inverter, changes your direct current from your vehicle, to alternating current, just like you have in your home. 120 volts is used in the United States of course, while we in Great Britain, and most of the rest of the world, use 220 to 240 volts. It goes without saying you need to get an inverter with the correct voltage output. See here for voltages around the world.:- http://www.kropla.com/electric2.htm
The next thing to consider, is the Wattage, Watts are just a measurement of power. (I use a capital W, because Watts are named after the Scottish engineer James Watt). A 100 Watt light bulb will four times more energy than a 25 Watt bulb. My inverter is rated at 300 Watts, so will power three 100 Watt bulbs, or even twelve 25 Watt ones! This is sufficient for my needs, but there are inverters with much bigger outputs.
To give you a rough idea what appliances you can use, we will use mine as an example. My 300 Watt inverter could supply a cell phone charger, a DVD player, a Playstation, (or a Wii, X-Box 360 or PS3), a 19"LCD TV, a laptop, even a juicer! or a fluorescent light fitting, even small power tools! You can only get this performance while the engine is running of course, otherwise you run the risk of a flat battery.
My inverter is like most others, has a single outlet, and is protected by a fuse. I have overload protection, and also thermal protection too. In the event of the input being less than ten volts, the inverter is supposed to turn off, but I have yet to test this. My model has wires fitted with "crocodile clips" that go direct to the battery, or can be plugged into the cigar lighter socket.
While driving, I can use a midi-stereo system, meaning I can use my Mp3 player. I did not have this facility in my car, apart from using earphones, and batteries in the player running out. Now I can play my "extra stereo" all the time I am driving, without flattening any batteries. I can even use the remote control.
These are now available for around fifty pounds, depending where you shop, and the output you require. The inverters are small, weigh very little, and are so useful. In an emergency, these can even be used as a source of power for lighting your house. (See here.) I can certainly recommend these wonderful items.