Working on part 3

So I've hit a big bump as far as King of the Dead goes. I'm detailing a large battle that takes place, and it's chewing up a lot of my time, but it will be the bulk of part 3. I'm trying to keep each chapter to around 15 pages, so you can keep track of where you are in the story with more ease, but I'm not sure if I need to break them down even further. What doe anyone think about a good chapter size? Right now, they sit at about
10k-15k words a chapter. Does 7 sound better?