Ideas for a laptop power supply/charger for my high powered laptop

I have been looking for a power converter/booster, so that I can wire it into my truck to power my high powered laptop. I could not find a suitable power device anywhere and resigned to making it myself. I have built many simple circuits and repaired a few circuits boards (mostly caps on computer motherboards) and the like. I found the following which almost fits the bill but can't supply enough continious power for my laptop. Below are the input and outputs I need.

Input Volts: 12vdc to 16vdc (standard automobile elec system)
Input Amps: I have up to 40amps on a fuse box tap.

Outout Volts: 20Vdc
Output Amps: 11Amps or 220watts. (more would be ok also)

The device I found that almost fits the bill is a PST-SR700-Adjustable
formerly PST-DU700, at this webpage

12 volt power supply catalog.

Could anyone offer a diagram capable to meet this above output needs? Or better yet a device already assembled that I can add on the connector that fits the laptop so that I can power/charge it in my truck.

Thank you for any info.

Wayne

Use the AC adapter that came with the laptop and go down to a local electronics store and buy yourself a small inverter, an inverter that small shouldn't cost you much.