I am not sure whether it is possible, but it would be really nice to work on my laptop while I am out on the roads. I have tried buying a converter which you can plug it in the lighter and the laptop starts working. But there is an issue with this thing as well. The laptop is only working when the car is running and it stops as soon as car stops. Now I am thinking of running it with two deep cycle RV batteries which are in parallel. How can I use two deep cycle RV batteries for my laptop? Can someone please give me relevant information regarding my query? Thanks.