Largest text size in iBooks?

I'm Blind and can use it

'm legally blind and use an iphone and ipad I love apple because they build zoom functions in to almost all there devices. I have not found a way to change the text size its self in ibooks but te zoom feature in accessibility you can zoom in on any screen very far. If you put the ipad in to portrait mode and. go to the home screen and zoom all the way in the battery icon will fill the top third of the screen. Its pretty easy to use with a little practice he will be able to read very well with the accessibility features. There is also voice over that will read text on the screen I am assuming it will read ibooks to you but I don't have my ipad with me right now to use. I left it in a friends car fail. I would try it out at the store it works great if you have any other questions feel free to pm me. sorry for any miss spellings/ grammer mistakes I'm blind and its very late