Well, they couldn't exactly have the Battle of Hogwarts because the D.A. wasn't implemented in the movies. I already knew there wouldn't be a battle scene at the end and didn't bother reading a shred of what was already in the movie.
Spoiler
I don't understand this part. I haven't seen the movie yet of course, but isn't the Battle of Hogwarts in the 7th book? Some elaboration would be welcome. Thanks.