>>2516453>>2514956Depends what you're using the laptop for and power requirements.
I have picrel and watched movies on my tablet for 8 hours straight and charged my phone at the same time and only used half a battery, I have 7 batteries so that's a long time.
A high end gaming laptop is going to use 250-300W so you're going to drain the laptop battery in an hour and a car battery in 2.5 hours. Then you're going to need to run a small generator(900W) every 3 hours for an hour, provided you have a fast charger that can topup your car battery in that one hour window. And you'll need a good deep cycle car battery, probably a marine battery otherwise you'll fuck it's capacity.