Marko is right about the inverter. Your tower would need 12, 5 & 3.5 volt regulated supplies. Since it is a switching power supply it may be possible to dump raw 12-16 volt into and let it do it's job, but SHOW ME
With the price of laptops nowadays, I would think that's the way to go. Cigarette chargers are available or cheapy 80 watt inverters will work. And in the long run, it should draw less power and less drain on the campers batteries.