Charging Laptop in car - battery life

My car have a 75W AC outlet, i was wondering if i can charge my laptop in my car during driving (my laptop said the 85W required)

also would it takes up my car battery life or it will be fine as long as i keep the car running during charging?

Thanks in advanced guys, i just got my first car 2 days ago.

you can charge it, no damage to your car, but it will take a long time and since your car doesnt have the neccesary wattage called for, dont know the effect on your laptop charger, may cause it to run/charge a little warmer than usual, could it shorten its life? dont know.

You can't suck 85w through a 75w outlet. You'll fry it and blow fuses or at least default the inverter to shut down from overage protection. Those inverters are also rated at 14.4v so they can advertise bigger than they actually are.

Go get a 100w inverter, minimum.

I believe your laptop may draw less than the rated power for charging only, so you may be okay.
Often power supplies show a rated max capacity, but that does not mean the laptop will actually draw that amount all the time. As far as I know, laptops consume more power when they are actually turned on and plugged in instead of just charging.

I suggest contacting your laptop manufacturer or going to a electronics repair store. They have equipment that can measure power consumption, and can measure the useage your laptop uses when charging only.

Try it.
Worst you can do is blow the fuse to the inverter in your car.