Over the past six months, the state of USB-C cables and chargers has been a minefield. That's OK, you tell yourself, just stick with stock accessories and all should be well. Except no. An independent researcher has discovered that even Google's boxed chargers for its Nexus phones can be defective, putting your devices at risk.
A fellow by the name of Nathan K, a self-described "Google Top Contributor volunteer ... who does independent USB-C cable, charger, and device verification and analysis on the side", recently posted on Reddit his alarming discoveries involving Google's own charging gear.
As the above video shows, mixing and matching Nexus 5X and 6P chargers and cables could be a recipe for disaster:
Now, watch what happens when I take the Google Nexus 5X stock charger and I plug it into the wall ... I'll be using the stock USB cable that comes with the Nexus 6P, just to show you I'm using all original equipment ... This charger goes Vbus hot, this means right now this is outputting 5V, 3A.
Nathan goes on to plug the cable into a USB hub, which (incorrectly) becomes powered. It also busts the hub's on/off button, preventing it from being powered down.
He elaborates on the behaviour in his Reddit post:
Does this apply for the 5X as well, or 6P in particular? It applies ESPECIALLY for the 5X. Bad Nexus 6P chargers get "easily tricked" into being Vbus HOT. The Nexus 5X is always Vbus HOT! :(
In the video's description, Nathan states he's already reported "within the framework of Google's escalations process" and "received permission" to reveal his findings.
So after all this, what's the safest course of action? As Nathan recommends, only use your Nexus 6P / 5X charger with the cord it came with. Don't mix them with each other or third-party accessories that aren't up to scratch. He provides a list of cables he's reviewed, but the US focus diminishes its usefulness.