Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

240W USB-C PD chargers are nearly here, says Framework CEO

theverge.com

Post reply on HN
Print view View original

21–30 of 138 posts

Re: 240W USB-C PD chargers are nearly here, says Framework CEO

#21

Post by zamadatix »

dtx1 wrote: post #2

It seems Gallium Nitride are quite the revolution in power density for charging equipment

It's been quite nice to have a 150 W charger in such a small form factor. Particularly since these charges tend to come with multiple ports in case you want to go from "I'm just charging my MacBook" to "I want to plug a couple of things in overnight at the hotel but don't want to pack a bunch of chargers". Typically that's some combination of my watch, airpods, phone, and laptop.

My current charger of choice is the Anker 747 150 W, 3 usb c (equal capabilities per port of 100 W) and 1 USB A (24 watts) but there have been a lot of other models released since then. Somewhere around ~240 W might be when I look at options again, right now my MacBook won't charge at full speed due to the 100 W limit on the 747.

Re: 240W USB-C PD chargers are nearly here, says Framework CEO

#22

Post by droopyEyelids »

thulle wrote: post #16
fnord77 wrote: post #8

why was 240W picked as the upper limit for PD? Why does there even need to be an upper limit?

I'd assume it's not specified as a upper limit but that it's just the highest voltage/current-pair currently defined. On a more fundamental level, there's the physics of how much power you can pass through a cable/connector safely.

This made me curious if it would ever be possible to see some material more conductive than copper in consumer cables.

Doing a quick bit of research there isn’t really any other option. Silver has 7% less resistivity than copper, but it tarnishes.

Aside from that, humanity hasnt discovered other options!

Re: 240W USB-C PD chargers are nearly here, says Framework CEO

#23

Post by kube-system »

TylerE wrote: post #17
fnord77 wrote: post #8

why was 240W picked as the upper limit for PD? Why does there even need to be an upper limit?

Because you have to size the cables based on amperage. The highest voltage supported by USB-PD is 20V. At 20V to deliver 240W you need 12 amps. That's already a fairly high number. At 300W you'd need 15 amps. So unless you want to drag around an NEC type cable as thick as one of your fingers, you need to set a limit. Edit: Fixed math. I haven't had caffeine yet.

That was my first question -- is this still going to be at 20V? The kind of current that would draw is crazy for those tiny pins.

Looks like the spec goes up to 48v now:

https://en.wikipedia.org/wiki/USB_hardware#USB_Power_Deliver...

Re: 240W USB-C PD chargers are nearly here, says Framework CEO

#24

Post by edgineer »

TylerE wrote: post #17
fnord77 wrote: post #8

why was 240W picked as the upper limit for PD? Why does there even need to be an upper limit?

Because you have to size the cables based on amperage. The highest voltage supported by USB-PD is 20V. At 20V to deliver 240W you need 12 amps. That's already a fairly high number. At 300W you'd need 15 amps. So unless you want to drag around an NEC type cable as thick as one of your fingers, you need to set a limit. Edit: Fixed math. I haven't had caffeine yet.

The 240W profile uses 48V

Re: 240W USB-C PD chargers are nearly here, says Framework CEO

#25

Post by ScottKolo »

TylerE wrote: post #17
fnord77 wrote: post #8

why was 240W picked as the upper limit for PD? Why does there even need to be an upper limit?

Because you have to size the cables based on amperage. The highest voltage supported by USB-PD is 20V. At 20V to deliver 240W you need 12 amps. That's already a fairly high number. At 300W you'd need 15 amps. So unless you want to drag around an NEC type cable as thick as one of your fingers, you need to set a limit. Edit: Fixed math. I haven't had caffeine yet.

While amperage is indeed a problem, PD 3.1 uses 48 volts to deliver 240W. https://www.usb.org/usb-charger-pd

That’s only 5 amps, but such a high-ish voltage is enough to lead to arcing. Charging cables are likely to require additional safety measures.

Re: 240W USB-C PD chargers are nearly here, says Framework CEO

#26

Post by rektide »

CoastalCoder wrote: post #7

Is it possible for a (laptop + USB-C PD power charger) to support multiple charging rates? My Lenovo Legion 5 has a 300W charger. Caveats: (a) I'm not sure if that's input power or output power; and (b) it's not a USB-C PD connector , but my question isn't specific to this laptop. Airplane A/C power outlets aren't willing to deliver that much power. And even if I was willing to slow-charge the laptop on an airplane o…

Great ask. There's no reason devices couldn't negotiate lower power. With USB-PD, power sources offer Power Delivery Objects: different charge modes they can do. It's up to devices to pick.

Right now most devices pick the highest power option (that they can handle). For a variety of reasons, it would be super sweet if we could pick lower power options! Maybe it's a multi-device charger & you want to leave more capacity for other devices. Maybe you want to slow charge your battery to extend it's life.

Almost every usb-pd device can accept lower power options, if plugged into a charger which doesn't offer the maximum rate. The only thing missing today is software, is user control over the power delivery negotiation process. Very very achievable, with minimal effort.

Re: 240W USB-C PD chargers are nearly here, says Framework CEO

#27

Post by f_devd »

TylerE wrote: post #17
fnord77 wrote: post #8

why was 240W picked as the upper limit for PD? Why does there even need to be an upper limit?

Because you have to size the cables based on amperage. The highest voltage supported by USB-PD is 20V. At 20V to deliver 240W you need 12 amps. That's already a fairly high number. At 300W you'd need 15 amps. So unless you want to drag around an NEC type cable as thick as one of your fingers, you need to set a limit. Edit: Fixed math. I haven't had caffeine yet.

USB-PD now supports 28, 36V & 48V as well because of the higher wattage limit[0] (240/48=5A which is about what the cables are rated for I believe)

[0]: https://www.usb.org/usb-charger-pd

Re: 240W USB-C PD chargers are nearly here, says Framework CEO

#28

Post by Springtime »

Will be interested to see if AllThingsOnePlace reviews it, as have been following their particularly in-depth power adapter reviews and their last review[1] of a Framework charger (a 60W model) showed it performed well both in efficiency and other metrics though not the highest performer or value in its wattage range.

Wouldn't ordinarily mention a Youtube channel on HN but felt their detailed testing, comparisons and teardowns would probably be of interest for the topic.

[1] https://www.youtube.com/watch?v=XyG8QEe6GIk

Re: 240W USB-C PD chargers are nearly here, says Framework CEO

#29

Post by parineum »

kube-system wrote: post #23
TylerE wrote: post #17

Earlier quoted context omitted.

Because you have to size the cables based on amperage. The highest voltage supported by USB-PD is 20V. At 20V to deliver 240W you need 12 amps. That's already a fairly high number. At 300W you'd need 15 amps. So unless you want to drag around an NEC type cable as thick as one of your fingers, you need to set a limit. Edit: Fixed math. I haven't had caffeine yet.

That was my first question -- is this still going to be at 20V? The kind of current that would draw is crazy for those tiny pins. Looks like the spec goes up to 48v now: https://en.wikipedia.org/wiki/USB_hardware#USB_Power_Deliver...

It's 48V.

Re: 240W USB-C PD chargers are nearly here, says Framework CEO

#30

Post by parineum »

awelxtr wrote: post #18
fnord77 wrote: post #8

why was 240W picked as the upper limit for PD? Why does there even need to be an upper limit?

I know that increasing voltage at those minuscule distances that usb-c opeates can cause electric arcs which is dangerous Increasing current on the other hand heats stuff up which... is also dangerous

USB-C solves the arcing problem in a similar way that CCS (EV chargers) does. It doesn't engage the high voltage pins until a low voltage pilot makes contact.

I'm not sure exactly how USB solves that for disconnecting (CCS locks the connector in) but I imagine the pilot would disconnect first and that would kill the PD pins during disconnect.

Post reply on HN