I've bought one form ebay, the seller says it's from an OEM. But Chinese sellers tend to think OEM stand for "Cheap Chinese knockoff" instead of "Original equipment manufacturer".
So I don't know, we'll see. lol
He shipped it using China post which is why I chose him instead of ibuygou. The prices are crazy there because China post no longer ships batteries unless they are stored within a device. So that makes you wonder if it even ships, it may never arrive. Too bad there's no tracking number.