Is Charging a Laptop in the Car Bad?

I'm going on a roadtrip and I was wondering if it'll harm the car's battery by charging the laptop while we're driving? Thanks!

Suggestion:

You ar possibly going to use an inverter to convert DC to AC then use your PSU to charge your battery (Unless you have an adapter to go from the 12volt car system to your system voltage)
Either way there will be no real effects on any of the items unless you get the wrong voltage going into your laptop