In fact, I don’t know of a way to disable the sync feature, other than disabling iCloud. It will back up your entire iBooks ebook library to iCloud, including the ebooks you have downloaded from free ebook sites (as well as the annotations for those ebooks). That first step is a killer, especially if your older iDevice can’t run iOS 9 (luckily you do have other options), but once you are past that point you should have no trouble at all.īased on what I have seen, and on similar reports over at MobileRead, iCloud for iBooks is automatic.