Mana Battery Class Six
 

This item was not added until Planes of Power. It is currently being sold by Adinel Jailbar in Iceclad Ocean, and quite possibly may be sold by other merchants as well.

No mention until PoP release, also lists PoP as required (and comments confirm):
http://web.archive.org/web/200211181...tml?item=16414

Fixed, pending update.