If you haven't bought the laptop yet I would suggest buying the omnibook line instead of the pav. There is a big difference between a retail and business laptop. The Pavilions, presarios, etc in the manufacturers home lines usually don't last past the warranty period. The business ones are the ones than run for years and are much sturdier built. As far as the power supply, some of the business line don't have the brick. Makes a much neater setup, just plug straight into the inverter. But if you do have a laptop with the small brick power supply, then the 12v version is just a dc-dc converter much like we built to eliminate the inverter to pc supply setup. You can also find third party power supplies for more popular laptops.