Within the past week or so (on June 14th, 2016), HP announced a recall program for select batteries from its various portable computer lineup (including Pavilion, ProBook, Presario, and Envy machines, among others).
While the batteries covered in the recall may be used in a wide range of HP's systems, the recall does not apply to all batteries. HP has supplied a quick program (usable in Windows) to validate the battery currently in a system. They have also provided a list of battery barcodes indicative of affected batteries if the program isn't an option for you.
So if you have an HP system from "March 2013 through August 2015" (or have procured a spare battery in or around that timeframe), be sure to check HP's site to see if you're affected.
Currently, details about the recall program can be found on HP's website at https://h30686.www3.hp.com/
