What DC to AC Inverter Should I Buy?

I'm interested in getting this new Dell Vostro for college reasons, and am finding myself in a situation where I may have to be using it in the car sometimes...

Laptop batteries typically dont last as long as it takes for me to study...so that's when I found out there are DC to AC inverters.

At first I was like there's my solution, but a little searching online told me I have to "beware" of what I buy when it comes to this. This is not like a conversion from 3.5mm to RCA, USB A to USB mini b, where all those types of converters are the same. Each DC to AC inverter seems to have its own specs.

So what should I be looking for? I've read laptops are pretty delicate and require a certain level of quality when it comes to inverters. I don't want my 400 dollar laptop to screw up.

Thanks for the help.

Sure. Because some are capable of running little more than a cell phone while others are designed to support a refrigerator and coffee pot with watts to spare. For sure, you need one capable of providing stable ~115VAC (in the US) with enough current capability to provide at least enough watts to meet the demands of the notebook's power supply, and it's load (the notebook).

Dell makes, or rather I am sure rebrands this 175W model and I am sure that will do fine. However, Dell also sells a Belkin 300W which I think would be a lot better for several reasons.

• The 175W model hangs out the lighter/accessory socket. Inverters are heavy and I think depending on the socket orientation, over time and many potholes, a mobile environment could strain the socket, and perhaps the plug too. The 300W Belkin uses a cord and you can relocate the inverter out of the way (as long as it can get ventilation - it looks like the case serves also as a heatsink).
  
• While I suspect 175W easily supports using just about any notebook while keeping a trickle charge on the battery, it might be taxed if the battery is fully discharged and you start placing heavy demands on the hardware too - depending on the notebook's hardware, amount of RAM, graphics solution and screen size. 300W leaves plenty to spare to plug in your phone too.
  
• The 300W Belkin is less expensive.