No - irrelevant was not only appropriate but less harsh than what I said to myself.. I did find the thread in the archive you mentioned along with the battery photos. I have not found a replacement battery for the PE but
www.ebookreaderdiscounter.com lists one for the edge. I know nothing about these folks but that's the only source I saw other than custom battery pack assemblers with large initial order requirements. I know hobbyists assemble their own packs but that's above my pay grade.