480, I've been wanted to get a variable voltage setup like that but don't want something so big. I see they have a mini variaiable voltage unit on the page you linked. May have to look into it.
They do have a "mini" but it is still really big. I tried the smaller ones and just decided to say frick it and got the biggest one I could find. Its so nice having a battery that lasts all day and a unit that REALLY works well. Its worth it.