Power Inverter

A power inverter can run all sorts of electrical kit in your car. But which one flicks our switch?

Auto Express Car Reviews

February 2006

Forget forking out for all those special car adaptors and chargers - buy an inverter and you can enjoy mains electricity in your motor to power phones, DVD players, laptops, games consoles and the like. For a fraction of the price of in-car options from makers of phones or PCs, you can simply plug in one piece of kit, cutting down on the cabin clutter and cable spaghetti.

Inverters are a great solution, particularly if you use your vehicle as an office on wheels. But don't get carried away thinking you'll be able to have power tools on tap just about anywhere! While the correct specification kit may be available, your battery will soon be sapped of power.

A 300-watt lamp pulls around 25 amps which, within minutes, will render your battery incapable of starting the engine. All our test units cut off when the supply dropped to 10.5 volts, but even at that level there is a good chance that your motor will not be able to spin fast enough to fire.

If you want to use a specific piece of equipment, check its wattage - this is usually marked on the casing, if it's not specified in the instructions or handbook. Inverters work best with loads that use a constant draw of current, such as computers or phones.

Kit which demands a heavy initial surge, such as a television, can often prove tricky, and you'll need a much more highly rated inverter to cope. And, of course, never plug in seriously power-hungry heat-producing kit, such as irons, heaters or hairdryers.

If you regularly use high-wattage components away from home, consider a small generator. Versions are available to cope with just about any load, although lower-powered examples are easier to store in the car boot.

Can it take the strain? We used a phone charger, DAB radio, coolbox and laptop on each unit to find out. A 100W lamp and 300W arc light provided further challenges. We also assessed the leads, connectors and specifications - particularly the continuous-draw figure, which is the most relevant.

Verdict

Although Ring's MP75 may seem an odd choice due to its maximum power rating, it's well priced and ideal for most typical uses.

The Nikkai made up for the lack of cigar-lighter plug with its brilliant performance at a very good price for those who need plenty of power. Carpoint's 150W did well, but the adaptor proved slightly irritating.