It’s been a while since Samsung has been in the news for its exploding Galaxy Note7 batteries— we sincerely hope any of our readers who bought one has returned it to the company for a refund—but a team of enterprising engineers developers who solve problems for a living may have discovered the root cause of the disaster.

Samsung has been mostly mum about the issue since it announced in October that it was suspending production of the popular phablet (more than a month after the first cases were reported), but all the while Instrumental has been researching the battery boondoggle behind the scenes. at it found is that the batteries themselves weren’t faulty; rather, Samsung’s push to make the case as thin as possible likely comprised them:

“The Note7’s lithium-polymer battery is a flattened ‘jelly-roll’ consisting of a positive layer made of lithium cobalt oxide, a negative layer made of graphite, two electrolyte-soaked separator layers made of polymer. The separator layers allow ions ( energy) to flow between the positive negative layers, without allowing those layers to touch. If the positive negative layers ever do touch, the energy flowing goes directly into the electrolyte, heating it, which causes more energy to flow more heat—it typically results in an explosion. Compressing the battery puts pressure on those critical polymer separator layers that keep the battery safe.”

Instrumental lends some credence to the theory that Samsung’s drive to beat Apple in the thinness game contributed to the problem, speculating that the changes might have come late in development of the hset the “newest versions of the batteries might not have been tested with the same rigor as the first samples.”

However, until Samsung releases some kind of an official statement, it’s hard to know for sure when the problem surfaced. For a multi-billion dollar recall, the company hasn’t been very forthcoming on what steps it is taking to rectify similar problems in future devices, despite repeated calls for transparency.

The impact on you at home: ether you bought a Galaxy Note7 or not, the prospect of your phone spontaneously combusting is a scary one. Any light that can be shed on what caused the issue is certainly helpful, until Samsung releases an official statement, we’re going to have to rely on these sort of third-party investigations to get any insight into the matter. It’s somewhat reassuring that the Instrumental blames the case rather than the actual batteries, it’ll be interesting to see how the design of the Note8 (assuming there is one) is affected by these developments.