That is never going to happen as device mfg's are abusing the standard and misleading consumers in not knowing these differences. Mfgs of devices have to design the power charging circuit to limit these higher voltages and wattages of those power supplies not meant for them, which increases costs of the device. Cheap devices will always catch on fire because they do not contain the protections needed to place limits on voltage and wattage.
All legit observations. But I was focused on the part where the new cables that can handle the higher performance features of USB-C are supposed to be rated as such, and companies are lying about achieving those ratings.
So here we go again with the cables. We are stuck having to trust the manufacturer and their claims.
USB-C is actually the specification for the Plug and Socket - the whole industry is in a mess
The charging ports on my own Dell XPS17 are rated at 180W, in order to provide the laptop with it's required 130W charge rating
Seems there's a lot of "Amateur Electrical Engineers" on this Forum. !!!!!
The specs for USB-C devices are quite well known -- High watts is fine if the powered usb-c device has to say connect to a multi-port USB hub with a load of HDD's on it (it's not the USB-C end though that's carrying the heavy current), but whether the charger runs at 5 Watts or 2000 Watts (unlikely !!!) the USB-C voltage spec is either 3.3 or 5V (can't remember which). Some of those external multi-port HDD enclosures which connect to a computer via a USB lead and have their own power supply will probably have a composite - one for the bus power / fan / chip etc for the "internal OS" and the standard output usb signal for the laptop or whatever.
There's no way you are going to get several amps through a bog standard usb-c connector without it going red hot. !!!! - unless you cool it in a bath of Liquid Nitrogen or have found a way to break the Laws of Physics.
The charging ports on a laptop are powered by the internal mains / battery supply to the laptop.
I'd love to see what device needs 140 watts via a SINGLE USB-C connector -- say 5V is the usb voltage then the current (I) by Ohms law (P=IV) is 140 / 5 = 28 Amps !!!!! which would blow away European electric kettles that usually run at 7 amps @220 volts which is a much lower amperage, It's the amperage that is the heat problem which is why European electricity A/C distribution usually use much higher voltages - 384KV than their US counterparts as thinner (and therefore cheaper) cabling etc can be used.
I could also charge my Car battery from a laptop if you could get 28 amps out from the laptops charger!!!!!!
Cheers
jimbo
This is the spare power brick I use for my Laptop
Amazon.co.uk
This is shown as supplied by a third party but mine was supplied direct from Dell- As you can see It's a 20 V 6.5A supply but any of the four Thunderbolt - ports on the laptop may be used to power and also for regular TB3 Power or data purposes
The power supply will only supply the current "requested" of it. Where we can see issues is if the some form of short circuit or other fault condition occurs and causes the drawn power to exceed the ability of the wiring to manage and raises the temperature . The standard protective system is some form of temperature break or "Fuse"
I see no reference in this thread to the PD (Power Delivery) technology, which both the charger and the USB-C port use to coordinate the charging process.
PD enables the fast charging process, adjusting the power (voltage and current) to the level of the battery charge. If the battery charge level is too low, power delivered to it increases to accelerate the charge, and gradually lowers as the battery is charged. That is why chargers that supports PD can operate at various power levels. PD 3.0 can operate up to 100W.
USB C Power Delivery revision 3.1 standards 2021 are up to the 240w region 48v in 2021.
Prior to that 100w based on 20v.
USB Charger (USB Power Delivery) | USB-IF
That article is hugely informative @Helmut. Thanks
On topic - notice these notations:
" Announced in 2021, the USB PD Revision 3.1 specification is a major update to enable delivering up to 240W of power over full featured USB Type-C® cable and connector. Prior to this update, USB PD was limited to 100W using a solution based on 20V using USB Type-C cables rated at 5A. The USB Type-C specification has also been updated to Release 2.1 to define 240W cable requirements, and with the updated USB PD protocol and power supply definition, this extends the applicability of USB power delivery to a large number of applications where 100W wasn't adequate. "
Also noted this:" New 28V, 36V, and 48V fixed voltages enable up to 140W, 180W and 240W power levels, respectively. "
Notice that the wattage divided by the respective voltage is 5A in each case.
Typically, 5A current can be handled by a 22 gauge copper wire.
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