Laptop battery life in Linux

I'm getting a laptop for Christmas and i wanted to know how battery life is in Debian compared to windows. I have heard that it gets significantly lower but i cannot find any good information on it. So if anyone has any experience with linux on laptops I would like to know how well your battery life is. If it is lower what would be some good ways to improve that.

 

same if not better due to overall lower cpu and hdd read/writes.

 

I get slightly better life out of my Eee. Best ways to improve it? Turn off wireless, bluetooth, camera. Unplug unnecessary usb devices. Dim the screen.