Determining Amp Rating For Carputer

Im working on the finishing touches of install on my carputer and need help figuring out the rating for the fuse to put inline w/ the power for the computer (the power that goes to the motherboard). The power cord that plugs into a socket in my room here says the following:

input: 100-240V~ 1.5A 50/60hz
Output: 19V----3160mA LPS

then at the bottom of the information on the power adaptor it says the following:

input: AC 100-240V 50/60hz 118-158VA
output: 19V----3.16A


is any of this info useful for determing the fuse to use for the power in the car? reason i am using the adaptor that runs in my room is cause the power source i have for using in the car doesnt include any information on the adaptor part, as its a multiple AC/DC options on it.

[Aleromaster]

I belive I had a 20 amp fuse feeding the computer power supply. But that was overkill. I think the cigarete adapter that I cut off the adapter had a 2.5A fuse in it but not sure