Though the saga of exploding batteries has been very disruptive to Samsung's Galaxy Note 7 roll-out, there have been one or two crumbs of comfort of the South Korean firm. Notably, units issued to the Chinese market — the launch of which occurred at the height of the recall drama — include 'safe' batteries unaffected by faulty SamsungSDI juice pack. Amperex Technology Limited, which has since assumed the lion's share of battery production for the Note 7 in general, has been responsible for the batteries inside devices hitherto sold in China. With reports of a device recently having caught fire in China, Samsung's botched release could have gone from really bad to much worse. However, the company has hastily noted on its website that this particular episode has been caused by external heat. 

Any repeat of spontaneous battery explosions in China would be disastrous for Sammy. The company declared Note 7 models sold in China as safe thanks to their Amperex battery components, which are also found inside the many units that Samsung has rolled out to replace faulty SDI ones. If it was discovered that devices were catching fire even with the Amparex batteries, the China launch — as well as the global recall -- would be in severe jeopardy.  

Thankfully for Samsung — as well as Note 7 owners in China and those who've exchanged their recalled model for a new handset — there's nothing to worry about. In this instance, says Samsung, the damage "was caused by external heating." Without getting too specific, the company added:

According to the burn marks on the sample, we surmise that the source of the heating comes from outside the battery, and it’s very likely that there was an external factor causing the heating problem.

It's quite possible that the owner of the device in question merely sought to capitalize on reports by intentionally heating up their device. Either way, if you've exchanged your Note 7 or purchased it since the recall, there's no cause for concern.