Solar Laptop Charger for Camping Setup

[MassiveOni]

heya,

i was just reading another post about a solar laptop charger, and i was getting a headache, and got lost in all of the posts, so i thought i would just start a new topic and ask again.

myself and my partner both have dell latitude laptops, i have the e6400 and she has the e6500, both use the same charger, blah blah blah.

what i would like to do is get a 12v car charger and a solar panel, to use to charge the laptop while we are camping for a few days, but i dont know how many watts the panel needs to be to be able to charge it.

the charger i was going to use is

the panels i have looked at are



or one like this



now they most likely wont me the one i get, they are just an example of what i am looking for, small enough to fit in the boot and store in the shed while not camping.

i dont know how many watts are needed to power the laptop

ok, my question is if the laptop input voltage is 19.5v 4.62a and the car charger is 12v, what panel would i need to power the laptop.

also before someone asks it doesnt worrry me if it "powers" the laptop, ie puts in as much power as the laptop is using, but i would like for it to be able to just recharge the laptop during the day, for use that night, i may even look into getting a few 12v batterys, which can be used at night, and recharged during the day.

thanks