MacBook, movies and battery life

[bgd]

Could people give me an idea of how long the battery would last on a MacBook watching movies using Quicktime?

I periodically travel between the UK and NZ and wondering how many hours viewing I could get before I have to abandon the massive 13'' screen for the risible airline offering.

 

[fatties]

this is not on quick time so not sure how its going to help but i get about 2+ a bit hours watching dvds + surfing net continuously on max light and max volumn... you should get more if its not a dvd right? (and dimmed down)