Play and Charge Kit
These are new, OEM, batteries and cords. I shamelessly ripped this off another deal site where the deals are slick (I am not sure if I can directly mention them).
I was about to buy some used one on AWD but these are cheaper and include the charging cord!
From the sounds of it, they are legit and also have a page on Amazon.
Example of GeniusMods product listed on Amazon