[ecomodded]

I have my inverter wired directly to the battery where it is fused with one of those car stereo fuses. I think doing it this way gives the inverter plenty of juice to invert.

I am thinking if you run a fused power line from the battery to your inverter it will start charging your big laptop with no problem.
Even being a big gaming laptop its charger should still not use more then 135 - 150w at full tilt boogie.

What you can do is look at the charger and read its output or amperage , times that by the volts & that will give you its max draw in watts.