After plugging in to charge, I get a message by the battery "not charging". What is wrong?
After about fifteen minutes plugging in to charge, I get a message "not charging" nest to the battery. What is wrong?
iPad Air 2, iOS 11
Perhaps a faulty charge cable or fault charging/power adapter block or both.
May need to replace one or both of these.
Even you have other known good charging cables and other charging/power adapter blocks, test with these.
If none of the above, you may need to purchase replacements.
Sorry & Best of Luck to You!