Can I use a cheap inverter for my laptop?

Question

I'm going to travel in a car this summer. It would be very nice if I could charge my laptop using the cigarette lighter.

Because my computer is from Apple, there's no way to directly connect the two, therefore I need an inverter that provides 120V alternating current.

There are many different models, ranging from very cheap to really expensive. The wave forms are: (from most expensive to cheapest)

• sine
• modified sine
• trapezoid
• square

Can I use just any inverter or does it have to be a sine inverter? If so, what happens to my computer in case I use the wrong one.

The laptop is a MacBook witch needs 60W.

Answer 1

Non-sinusoidal waveforms can introduce harmonics into the system which can cause anything from an annoying buzz from the speakers to disruptions in less-tolerant electronic components. Try to go for at least "modified sine".

Answer 2

I've charged/used my MacBook Pro off of a cheap $30 charger from RadioShack - I think you'll find that they're designed to work with most consumer electronics and that they'll be quite sufficient as long as you have enough wattage.