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USB-C Power Meter Helps You Spot Counterfeit Accessories Before They Fry Your Gadgets (gizmodo.com)
USB Type-C cables are not all created equally. In fact, some USB Type-C cables fail so badly that they will permanently damage your hardware. Benson Leung, an engineer on Google's Pixel team, discovered early last year that there's even more risk to your electronics when you've got a cheap USB-C cable with an older USB connector on the other end that doesn't properly regulate power draw. In an effort to weed out the bad cables from the good, a company called Satechi has released a "Type-C Power Meter" that makes it easy to tell if your USB-C gadgets are at risk of getting fried, or under-powered, by a sketchy accessory. Gizmodo reports: The simple pass-through adapter connects between a USB-C cable and a USB-C device, providing real-time data about the power draw, in either direction, including details about voltage, amps, and the amount of energy that's been transferred since it was first plugged in. The monitor can let you know if an external battery pack is providing the proper amount of power to a smartphone that it claims to, or if your MacBook or Chromebook is receiving sufficient power from a charging cable connected to its USB-C port to actually charge the battery. What the monitor can't do, however, is protect a device if there's a detected problem in the power flow. It's not a surge protector, nor does it have any built-in alarms or warnings because it has no idea what the power requirements are for whatever device you're using it with. You'll have to make sure you're aware of how much power a device is supposed to be drawing, and confirm that it matches what the Type-C Power Meter is reporting, as soon as you plug it in.
What bugs me about USB power is that the negotation for more than a tenth-amp (half-watt) takes place partly on the data lines. That means they need to be connected between the peripheral and the source.
So any charger device for a power-hungry gadget (such as a smartphone) will have a full four-wire connection and have the opportunity to attempt to exploit any USB port vulnerabilities of the device. Making a "condom" adapter to only connect the +5 and ground wires will normally provide reduce performance (if it works at all). Vetting one that does connect to the data lines on both sides is difficult - both to insure that it does what's intended and doesn't have a backdoor, and that it, itself, isn't such an attacking device.
Given that Russian intelligence was already caught handing out phone-cracking "USB chargers" to many countries' high officials at an international conference, the threat not just a hypothetical.
(Note that some powered hubs just tie +5 and ground to the supply, rather than try to negotiate and enforce per-port power limits, too.)
IMHO: A USB device that depends on its power source to limit its input current, and can be damaged by a host that is willing to deliver more current that it requested, is defective by design. The negotiation and enforcement is for the benefit of the power source (for instance, a laptop trying to protect its battery life).
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
No, the main reason is bad standards and poor regulation. Even for the well educated, there's no good way to tell apart a bad device from a good one.
I've heard thar we're not actually supposed to read the fine summary, but I did so anyway, and couldn't help thinking that a better title would be, "USB C Power Meter Helps You Spot Counterfeit Accessories While They Fry Your Device". But maybe that's just me.
Il n'y a pas de Planet B.