Battery shows up on the options/settings screen when you press on the center just like for the clock, or on the home page screen. When reading, all you see is the text and the page number.
The page numbers are shown on the bottom, but they are not always exact since when you change font size/type/etc., the screen could really be showing the ending of page 72 and beginning of page 73, but it'll just say page 72 on the bottom. If you want, you can change the options to show the real page number on the right side. It'll then appear on the right side at the end of whichever line is the real new page.
Not sure if that's confusing or not... but it's pretty simple when it's in your hands.
