iPod Ipod battery life and Movies

I tried searching this but I can't find any info..

I put 2 movies on my ipod classic because I am going on vacation in a few weeks and I thought it would be cool to have a movie to watch on the plane. Do watching movies drain the battery more faster than listing to music?

THANKS

Thanks, I tried looking for something that would add longer life to the Ipod, like an external battery but I haven't had any luck. Does anyone know of anything I can plug in to my ipod for extra battery life?