> The only slight snag is some cheaper itema refuse to use PD and insist on plain 5V/2A - buy most decent travel chargers have NON-PD ports.

Every PD port will handle non-PD USB-C consumers correctly, so not sure why would you care about non-PD ports. There is no "plain 5V/2A" in USB-C though, it's either plain USB (100/150/500/900mA depending on enumeration state), 1.5A or 3A. If you want to advertise exactly 5V/2A, you need PD.

Same!

I've also returned a few USB devices that ship with a USB-A to USB-C cable and ONLY charge in that mode, they also MUST charge with USB-C PD.

The two so far were a therapy light and some Zippo hand warmers. Like, who in the hell would design a device that has a USB-C port on it where only a fraction of chargers will work on it. It feels even worse than proprietary charges, because you see a USB-C port on it and think, oh I have a plug that fits it, and then it doesn't F**ing work. Idiot engineering/product teams, making the world suck with their falsely advertised USB-C ports. If anyone of you are on a team that ever makes this decision, just know that it is a stupid decision, and jump ship when you can.

I'm hoping we'll see most e-bikes at least use 240W usb-c pd charging (I figure I have about a decade until I will wish I had some assist and buy one, so probably by then, they'll have gotten there...)

I also have assorted products that won't charge c-to-c (some from respectable manufacturers even, like Philips), but I see you can get little adapters with 5.1K resistor you plug into said crappy devices to cover that, I will have to try some out.

I'll bite. What type of watch do you have that has a direct USB-C port on it?

I think you are confusing the devices with USB-C that require USB-A, and devices that charge the standard USB-C 5V/3A/15W. The USB-A ones cheaped out in including the resistors that signal legacy USB mode, they work with the ones in the cable or adapter.

Lots of people assume that USB-C always uses USB-PD, but the basic signalling is done with resistors. Lots of devices only need 15W, and it is better than USB-A charging. If you want faster charging, buy more powerful chargers.

What toothbrush do you have? I've been looking for a USB-C charger for mine (standard Oral-B toothbrush) but the only ones I've found were from no-name Chinese brands and didn't work at all.

For travel I have a bunch of cables with adapters on the end (choose usb-c, lightning, micro-usb). Can use usb-c, but have the ability to use the others.

It has helped out in a bunch of unexpected situations (usually someone else's device)

we are talking about a lightweight charging cable. you can carry more than one. boom, redundancy. being ideological about a cable connector is the nerdy equivalent of jony ive obsessing over macbook thinness.

You can always use a „PD Decoy“ if the voltage is USB compatible. A 5 / 9 / 12 / 15 / 20 Volt barrel plug is trivially USB powerable.

USB-PD 3.1 provides both a Get_Battery_Cap message, which asks the sink to tell the source the capacity of its battery) and a Get_Battery_Status message, which asks the sink to inform the source about the current charge of its battery.

Here's an example capture of an exchange between my MacBook Pro and iPad: https://imgur.com/a/8rZlN9X

The iPad responds to Get_Battery_Cap with Battery_Capabilities, which reports the total capacity in Wh:

USB Vendor ID: 0x05AC Product ID: 0x0000 Design capacity: 280 Last full-charge capacity: 280 Battery reference: valid

And then when the MBP asks for battery status, the iPad returns a Battery_Status message:

Battery is present. Present capacity: 14.2Wh Charging state: charging.

Later on, as the charging continues, the iPad will issue an Alert message:

Reported alerts: Battery status changed. Affected batteries: Fixed battery slots: 1

And then the MBP will send a Get_Battery_Status again, and so on. (Example capture here: https://imgur.com/a/TI5maV0

What's really cool is that this exchange happens both ways—the iPad also sends a Get_Battery_Cap message to the MBP, because it is also capable of acting as a source, and, if the laptop's battery drops sufficiently low, the source/sink roles may swap (using a DR_Swap message) so that the iPad ends up charging the MBP!

Yes, since PD 3.1 (see "Get_Battery_Status" request).

The vflex has a status LED that shows negotiation status. When it fails it will still output 5V, though, they don't seem to have any mosfet to switch the output off entirely.

https://werewolf.us/

I don't think I've ever seen one of those type of converters output anything but 5V upon negotiation failure. Which one did you use that did that? Their logic being "pick the closest available voltage" I presume?

Those are called trigger boards. I haven't found one with buck converter to make 12V. 12V is in earlier PD standard so lots of chargers support it but you have to check each charger and lots don't say. The guaranteed solution is PPS chargers that have variable voltage.

iirc theres ones that do. However I dont recall there being any clean fix to the amperage constraint issues. Especially when a lot of usb-c chargers will vary output as they heat up with usage.

Which is kinda part the issue, usb-c charging bricks, they aren't usb-c power supplies, there is no expectation of sustained output capacity. Thankfully at least some the multiport ones have renegotiation more or less solved cleanly rather than what is essentially rebooting the PD controller.

There are things like this: https://www.adafruit.com/product/5501 haven't used it, trying to find one for my mini pc, mostly so I can use a usb c power bank as a tiny DC ups.

Actually, that was 5v, not 9!

I have a couple like that in my mini rack. The problem is the power supply: these take 65W, so I figured I could get a quality 140W charger and power them both, but it turns out that things like "unplugging something else" would kill their power. I had to spend a lot more on a StarTech charger to get the performance I needed

The issue is that a USB charger is not a USB power supply. A charger does its best, but makes no guarantee of constant power delivery or duty cycle. The power supply absolutely must provide its rated output at 100% duty cycle.

A lot of SFF PCs already come with a power brick. Just with a 12V barrel jack instead of a USB-C port. Compared to that design you really wouldn't safe much space. Though I admit that USB-C would be convenient. Maybe with a tiny battery

> And if USB-C could somehow provide a range of voltages to the motherboard, SFFPC's could be downsized even more

You reeeeeeally don't want to do that. Cable inductance is a big deal, among other issues. You want the main DC-DC regulators on the board, usually right at the load, for the main loads. Most of the PSU bulk is for dealing with mains itself: handling 50/60Hz or mains isolation is just physically large. Getting in secondary 20V DC (or so) from a single connector and then regulating it down on board is pretty much the ideal solution.

(I can't even begin to comprehend the horrors of a USB-PD negotiation involving multiple voltages. It's already the worst standard I've ever had to deal with.* Don't make it worse!)

(* Not hyperbole, it is truly, truly awful. At least things like 60601 are bad because, you know, they're covering lots of stuff like lifesaving medical devices. USB-PD is... holy hell, it is just bad.)

There are some SFF PCs that can take USB-C power.

Lenovo have some,but sometimes require adapter cards. And a few of the Chinese N150 units will take PD power

It's great for hot swapping and more portable than a laptop.

You joke, but this is enough to make recharging an e-bike practical. E.g. https://amplerbikes.com/pages/nova

That's only a single ampre at standard European mains voltage. It's still a lot of power for those tiny connectors and insulation, but an order of magnitude insufficient for those appliances.

I bet that cable gets plenty hot at 200+ watts.

I remember scoffing years ago at USB powered coffee warmers. Maybe the situation has changed.

I mean my electric Fan and standing lamp are both powered by USB-C.

There are things that shouldn't be powered by USB-C. But there are plenty of sub 100W consumer electronics devices that really should be USB-C. I waited years before Panasonic released their lamdash shavers using USB-C.