Hah. Glad to see this.
While this doesn't happen with the original lightning cable and charger,
it happens with another one from my iPad Air.
I suppose it has to do w/ the current and cable-resistance in my case, as I have it attached to an USB extension chord (although it is indeed weird it only happens when it reaches a 100%)
leaving the charger in there after getting the message, even though it does not look like it is not charging anymore, I really think it is. I have been streaming music for like a half hour and it has not moved beyond 100%