back to article USB-C levels up and powers up to deliver 240W in upgraded power delivery spec

The USB Promoter Group has announced the completion of USB Power Delivery Specification Revision 3.1. Wake up! This is no mere standards document, because this one improves USB-C’s power-carrying capacity from 100W to 240W, where implemented. “With the new capabilities of USB Power Delivery 3.1, we now enable higher power …

  1. Mishak Silver badge

    Gaming laptops

    I know someone who has a gaming "laptop" that needs two 300W+ PSU's if it is ordered with the highest spec graphics card. One of these weighs more than my laptop and PSU combined!

    1. katrinab Silver badge
      Mushroom

      Re: Gaming laptops

      Like the Alienware Area51m R2?

      10900K + RTX 2080 Super.

      Very nice specs, but utterly dumb to put that in a laptop enclosure.

      Reviews are mostly - "battery life is rubbish but I expected that"

      1. Mishak Silver badge

        Re: Gaming laptops

        Not sure if it was that one, but something similar - he sees the battery as a (short term) UPS and nothing more!

        1. Cederic Silver badge

          Re: Gaming laptops

          One power supply rather than two, and I bought a second power supply for my overnight accommodation rather than carry one around, but I did buy a laptop of that ilk when I was working away from home four nights a week.

          Meant I could use the same computer in both locations with minimal fuss and still get 'better than the average desktop' levels of compute and graphics.

      2. Tomato42

        Re: Gaming laptops

        they're not dumb, they are a desktop PC you can put into a single backpack

        1. Pascal Monett Silver badge

          We have Internet today, there's no need to lug around a computer to game with friends anymore.

          Every Monday and Friday I have a gaming session in the evening with my friends. We play a range of games and we chat via Teamspeak at the same time. Works fine.

          Of course, if you want to participate in a LAN competition, we're not talking about the same thing, but even then, I would think there are some who prefer to lug around their tower instead of trusting a laptop.

          1. Snake Silver badge

            RE: gaming in a backpack

            "We have Internet today, there's no need to lug around a computer to game with friends anymore."

            I don't game. So, for me, these rather 'luggable laptops' are workstations that fit into a backpack. They are excellent for those with small apartments yet still wish some horsepower, or those with multiple locales that they wish to power-work from.

            For me, both qualifications apply. When COVID hit I packed the laptop and left my weekday flat to stay in my rural home. All my data, applications and conveniences came with me without having to attempt to drag a desktop around, with monitor, on public transportation.

        2. katrinab Silver badge
          Unhappy

          Re: Gaming laptops

          I hate to imagine what the thermal throttling would be like with those components in a laptop enclosure.

          1. MacroRodent
            Happy

            Re: Gaming laptops

            > I hate to imagine what the thermal throttling would be like with those components in a laptop enclosure.

            Maybe add a pair of plugs for circulating cooling water? We need a standardized H2O plug specification.

            1. Fred Flintstone Gold badge

              Re: Gaming laptops

              We need a standardized H2O plug specification.

              Gardena, Hozelock ...

              :)

              1. MiguelC Silver badge
                Alert

                Re: Gaming laptops

                personally, I wouldn't want those leaky bastards anywhere near my laptop

                1. Anonymous Coward
                  Anonymous Coward

                  Re: Gaming laptops

                  If you treat a proper Gardena plug well and use the right hose, leakage is impressively minimal, but one cheap imitation in between can ruin it.

                  Also, joke :)

                  1. Anonymous Coward
                    Anonymous Coward

                    Re: Gaming laptops

                    Hoser

  2. Erix
    Mushroom

    Coming soon

    USB Power Delivery Specification Revision 4.0: use your USB-C cable to charge your Tesla.

    1. Fred Flintstone Gold badge

      Re: Coming soon

      It's probably going to be the reverse soon given the way "G" specs drive higher and higher power use: you'll need a Tesla to keep your 10G mobile phone powered..

    2. Anonymous Coward
      Anonymous Coward

      Re: Coming soon

      I can't wait to have an extremely high wattage USB-C socket on a cellphone.

      I've always said it, ever since the Apple campaign "there's an app for that" well I can't indulge in my glass blowing hobby on a train, or smelt gold to make jewelry on the tube or toast a sandwich for my lunch on the go. I also can't perform an impromptu spot weld on a busted bus shelter when I see it.

      With this new spec we're one step closer.

      1. Irony Deficient

        Re: Coming soon

        I can’t […] toast a sandwich for my lunch on the go.

        I take it that this device never appeared in your local kitchen appliance shop? (Its cradle could be powered by a portable battery pack if its internal battery doesn’t last until your lunchtime.)

    3. Version 1.0 Silver badge

      Re: Coming soon

      This means I can make a pot of tea just by plugging the kettle into my laptop.

      1. Anonymous Coward
        Anonymous Coward

        Re: Coming soon

        .. as opposed to putting it on top (I had one of those, not really suitable for the "lap" part of a laptop) as it got *seriously* toasty.

    4. Anonymous Coward
      Anonymous Coward

      Re: charging your Tesla

      you are making the assumption that

      1) Everyone would want to own one

      2) Everyone could afford one

      3) Other and often better EV's are available.

      Personally, and after a brief period owning a Tesla, I would not want to be seen dead in one ever again.

      I now drive a Polestar. A vastly superior vehicle and no I don't care about full self-driving or operating my car as a Robotaxi.

      As for charging it over USB... 240w is an awfully slow way to charge a car.

      call it 250W. That's 4 hours per kW and for an 80kWh battery that 320 hours or more than we week.

      I wish you well. Personally, I'd rather watch paint dry.

      1. Anonymous Coward
        Anonymous Coward

        Re: charging your Tesla

        Polestar - that's a Volvo isn't it?

        I think your post pretty well identifies you as a Volvo driver. Don't forget your hat.

        1. runt row raggy
          Coat

          Re: charging your Tesla

          don't be silly. a "polestar" is a successful stripper. and i don't think it's spelled "volvo".

          1. richdin

            Re: charging your Tesla

            ua for the UX

      2. Anonymous Coward
        Anonymous Coward

        Re: charging your Tesla

        It just takes some time to getting into watching paint dry. The problem is usually that it's dry by that time.

    5. Inventor of the Marmite Laser Silver badge

      Re: Coming soon

      I've already seen on the 350kW EV chargers, that the cable is water cooled.

      They're still bloody heavy cables though.

  3. batfink

    I predict excitement

    So, the average punter is going to use any old USB-C cable, because it fits in the hole. Then they're going to pump a nice amount of current down it. What could possibly go wrong?

    1. Stuart Castle Silver badge

      Re: I predict excitement

      Probably the same thing that happens when people try and chuck a full 13 amp load down a cheaply made mains cable that can barely cope with 3amps.

      1. Anonymous Coward
        Anonymous Coward

        Re: I predict excitement

        That's actually one of the two arguments in favour of the UK style lump of a power connector:

        1 - it is fused to the capacity of the cable (although tt's too easy to insert an unsuitable fuse).

        2 - it ensures you know which lead is live and which is neutral so you can place a switch in the right wire.

        That said, from a risk managament perspective option (2) is maybe not good because it creates an assumption with a latent possible error condition, whereas most European plugs are symmetrical and thus force switches in both leads.

        1. IanRS

          Re: I predict excitement

          Switches in both leads might be the required practice these practice these days. It might even be carried out in new installations. However, it is certainly not always in place in older installations. Light sockets in particular can still be live even when the switch is off.

          1. Anonymous Coward
            Anonymous Coward

            Re: I predict excitement

            I have not touched any live part for decades now without first testing for live current. Somewhat OCD I even do that with power down, but I figured it's a good enough habit not to break it for the sake of appearances. Leaving it automatic means I'll even do it when I'm distracted, which does happen.

            In my younger days (long ago, thus) I did manage to accidentally hook myself up to 220VAC and didn't like it much. I liked a brief encounter with 380V even less, and I think that's about the last time I touched potentially live metal without testing.

            1. John Robson Silver badge

              Re: I predict excitement

              "I have not touched any live part for decades now without first testing for live current. Somewhat OCD I even do that with power down, but I figured it's a good enough habit not to break it for the sake of appearances"

              Not OCD at all...

              How do you know that you.ve powered down the right circuit without testing for live *before* you turn the circuit off, and then again afterwards?

              1. Joe W Silver badge
                Pint

                Re: I predict excitement

                And depending on your measurement device you need to test a known live wire afterwards as well... to others it might look like OCD, but I enjoy living all the same, thank you very much.

                So thumbs up and have a cold one (_after_ workin on the electricity stuff).

                1. The First Dave

                  Re: I predict excitement

                  I've always lived by the mantra of "assume it is live, regardless"

                  And never had a shock from the mains.

                  1. Anonymous Coward
                    Anonymous Coward

                    Re: I predict excitement

                    never had a shock from the mains

                    Ah, but then you don't know what you're missing.

                    :)

                    1. N2

                      Re: I predict excitement

                      Its only 240V AC

              2. Terry 6 Silver badge

                Re: I predict excitement

                I've mentioned this one on ElReg before, but it's quite appropriate here.

                Many years ago I was changing the light switches in my newly bought ground floor flat. Though I'd turned off the mains I obsessively checked each wire with a mains testing screwdriver. And the one by the front door lit up. It turned out that the previous owner's old mum had lived in the flat above, with the entrance adapted to allow access to both flats. So he'd wired the light switch to the upstairs flat in some Byzantine (and I'm sure illegal) way. Which meant it was still live.

                So no, it's not OCD, it's just trying to stay alive.

                1. sebacoustic

                  Re: I predict excitement

                  so now she's got a bitcoin rig dangling from the porch light fitting...

                2. PRR Silver badge
                  WTF?

                  Re: I predict excitement

                  > I obsessively checked each wire with a mains testing screwdriver. And the one by the front door lit up.

                  Terry's upstairs controlling the entry light *may* have been a legal connection. Stairways often have switches top and bottom for obvious safety reasons. This causes much confusion because There Are Many Ways To Do It(T).

                  My true tale: House from 1830. Original wiring by Tom Edison. Much later wiring done by homeowner's 'clever nephew'. The kitchen had no grounds, despite 3-conductor cable. That can be fixed. Best with power off. Breakers not clearly labeled, of course. So I plugged-in a radio and turned breakers off-and-on one-by-one. The radio never faltered.

                  WTF?? I reversed the game. ALL breakers off. The radio DID shut-up (otherwise I'd be rich selling perpetual power). Breakers on-and-off one by one. TWO breakers killed the radio.

                  The idiot had wired two 20A breakers onto the same 15A circuit. Not in the panel, that would be too easy. I had to open EVERY outlet box and un-do most of the screws to find the cross-connect.

                  Note also that on US 120-120 split there is a 50% chance of mis-wiring this wrong and making a 240V short circuit. Which may explain why the panel wiring looked odd.

                  1. Ken Moorhouse Silver badge

                    Re: Breakers on-and-off one by one. TWO breakers killed the radio.

                    Fred Karnaugh's Circuits springs to mind.

                  2. Terry 6 Silver badge

                    Re: I predict excitement

                    These were two separate flats. They'd temporarily ( and without planning permission as far as I could tell) been given a single entrance for upper and lower flat. But both had their own mains supply and been returned to two flats ahead of the sale. Unfortunately he'd not sorted out the light switches by the entrance.

              3. Anonymous Coward
                Anonymous Coward

                Re: I predict excitement

                "How do you know that you.ve powered down the right circuit without testing for live *before* you turn the circuit off, and then again afterwards?"

                Nonono... the right question is "How do you know some yutz hasn't taken an angle grinder to your tagout padlock so he can charge his phone?"

                1. Inventor of the Marmite Laser Silver badge

                  Re: I predict excitement

                  Upvoted just for "yutz"

            2. sebacoustic
              Boffin

              Re: I predict excitement

              In my younger days I had a pysics prof tell me that a "proper" lab scientist needs an electric shock every so often, one kV making you feel "quite lively".

              Nowadays i mostly turn off the power when working on circuits though I have done it without, being careful, and knowing that the off 240V zap does little harm.

              When working as an electrician (in even younger days) in a working factory, sometimes it was considered unavoidable to wire something up while live, with well-insulated tools, shoes, and an abundance of caution.

              1. Anonymous Coward
                Anonymous Coward

                Re: I predict excitement

                It's only less dangerous if you're insulated and only make contact at one point so you get a decent warning but no current flow that will freeze your muscles so you can't let go, messes up your heart rhythm and does some cooking along the way from point A to point B via your body.

                I've been there too, things that could not be switched off. I have found that after considerably simplifying my response to such request ("no"), solutions could be found.

                Electricity deserves respect - it can and will kill you if given half the chance.

            3. MachDiamond Silver badge

              Re: I predict excitement

              " I liked a brief encounter with 380V even less, and I think that's about the last time I touched potentially live metal without testing."

              I used to work on test equipment and the CRT on a oscilloscope may be small, but it's still over 1kv. Only did that once. I love the LCD models.

        2. Danny 14

          Re: I predict excitement

          most plug in brick PSUs are double insulated so wont be fused though. The earth pin will be plastic.

          1. Dr_N

            Re: I predict excitement

            And by "double insulated" it normally just means a tougher plastic enclosure.

          2. The First Dave

            Re: I predict excitement

            Double-insulated does indeed imply 'not earthed', but it MUST still be fused appropriately.

            1. the spectacularly refined chap

              Re: I predict excitement

              Double-insulated does indeed imply 'not earthed', but it MUST still be fused appropriately.

              No, the fuse is there to protect the mains flex, not the appliance. If there is no flex (e.g. plug top PSUs and chargers) there is no requirement for a fuse nor is one usually provided.

              It's also quite possible for a device to conform to both class I and class II, in which case yes it is both double insulated and earthed. A device I'm working on right now does exactly that. Wooden enclosure and double-insulated construction. However inside there is a florescent lamp ballast and low voltage PSU module. Those are metal cased, not usually live but they are still earthed, even though it would not be a dangerous condition by itself if either case did become live.

        3. sreynolds

          Re: I predict excitement

          There is a such a huge design flaw in the UK and EIRE plugs - anyone who walks around without shoes in a house knows - is that the flat plug when upside down causes immense pain.

          1. Anonymous Coward
            Anonymous Coward

            Re: I predict excitement

            No, no, that's by design.

            It ensures that nobody leaves plugs lying around, and at least triples the chances you'll be able to find a plug in the dark. All you need to do is to take off your shoes.

            Is it Friday yet?

            :)

          2. Nick Ryan Silver badge

            Re: I predict excitement

            Yep, but it makes them so much easier to find in the dark...

          3. the spectacularly refined chap

            Re: I predict excitement

            There is a such a huge design flaw in the UK and EIRE plugs - anyone who walks around without shoes in a house knows - is that the flat plug when upside down causes immense pain.

            That is by design and a safety feature. The right angle design and square pins make it impossible to plug a device by yanking the cable. That avoids the flex becoming damaged near the plug. Does make for a trip hazard but less of a fire risk.

    2. Fred Flintstone Gold badge

      Re: I predict excitement

      Well, that's the exact reason USB-C cables have chips in the connectors. The cable tells the power supply what it's capable of.

      1. Mishak Silver badge

        Re: I predict excitement

        Hmm. I used a Belkin (I think) one to power my Macbook once - it was thicker than the Apple cable (which I did not have with me), but it got alarmingly soft in use!

        1. Wade Burchette

          Re: I predict excitement

          Learn a lesson: Never ever use anything Belkin, no exception. That now includes Linksys. To say Belkin products are garbage would be an insult to garbage.

          1. ITS Retired

            Re: I predict excitement

            I've never used a Belkin anything that worked up to the package description it came with. It is reassuring to know I'm not alone.

        2. Anonymous Coward
          Anonymous Coward

          Re: I predict excitement

          The magic word is "Belkin". Let's just say that I'm no fan.

      2. Graham Cobb Silver badge

        Re: I predict excitement

        And what stops knock-off suppliers making cheap USB-C "extension" cables with a plug on one end, a socket on the other, and straight through wiring, with no chips involved?

        Is negotiation clever enough to detect deliberate rule-breaking like that?

        1. Anonymous Coward
          Anonymous Coward

          Re: I predict excitement

          Yes, without the chipset it defaults to being a boring USB-A cable (5V 1..2A)..

      3. Roland6 Silver badge

        Re: I predict excitement

        >The cable tells the power supply what it's capable of.

        But not the user...

        So we can expect complaints that my super-duper device isn't charging, only to find that the wrong plain black USB cable was selected from the drawer...

        1. Cynic_999

          Re: I predict excitement

          No different to the complaints that a USB device is not connecting to a PC - because a charging cable that does not haver the data lines connected was used.

          1. doublelayer Silver badge

            Re: I predict excitement

            And anyone who has some power-only USB cables knows how irritating that situation can be. It's gotten to the extent that I'll give away or recycle any power-only cables just to avoid it. So maybe a labeling requirement isn't so bad after all.

        2. Androgynous Cupboard Silver badge

          Re: I predict excitement

          > But not the user...

          You're not wrong. Even the thickest of the thick has a fighting chance of picking up a cable and identifying it from the plug, but no more. The ebay cable purchase lottery has already become stacked against you, just as it is with other things-that-look-identical (eg microSD cards)

          1. Roland6 Silver badge

            Re: I predict excitement

            >The ebay ... purchase lottery has already become stacked against you, just as it is with other things-that-look-identical (eg microSD cards)

            Just sourced some mPCIe WiFi adaptors and M.2 SSD's - where not only do you have to worry about pins and keys matching, but also the card size fits the laptop and that (in the case of the WiFi adaptor) the chipset used on the card is compatible with your motherboard chipset...

            I thought I was intelligent, but am beginning to think I might be a bit thick! :)

    3. Dan 55 Silver badge
      Mushroom

      Re: I predict excitement

      No problem, the negotiation phase will sort that out.

      I mean, there's never been any problems with USB 3 or USB C chargers or cables before, have they? Especially off-brand ones.

      1. Anonymous Coward
        Anonymous Coward

        Re: I predict excitement

        "never been any problems with USB 3 or USB C chargers or cables before, have they"

        I know where you're coming from but maybe think of it like this and see whether anything changes: dodgy "USB" charging gear has probably killed more people than (say) Grenfell Tower. Both caused in large part by pennypinching and or deliberate dodging of the rules.

        Information sources include London Fire Brigade, Electrical Safety First, etc.

    4. Neil Barnes Silver badge

      Re: I predict excitement

      Yes, because the cynic in me expects that there will very shortly become available cables which claim to be able to handle the power, even in the negotiation phase, but lie...

    5. John Riddoch

      Re: I predict excitement

      I'm really hoping the standards makers have thought of this and made sure that chargers can't supply too much and devices won't accept too much unless they detect the appropriate conditions at all 3 points (charger, cable, device). Not easy to do while maintaining compatibility, but I know from experience that fast charging doesn't work with any old cable, so there's something there already.

      Not all chargers or cables are equal and navigating the compatibility between them all is a pain.

    6. Sorry that handle is already taken. Silver badge

      No excitement in most cases, unfortunately

      No, the controller will detect a high impedance cable and send the appropriate number of elections down it. No more (and usually far fewer) than it can handle.

      Have you ever noticed that if you plug your phone and the cable it came with into its 2A charger, it will deliver 2A, but if you throw it on a cheap ebay cable, it will deliver 0.5A? The charge controllers are generally designed to deal with low quality cables with minimal drama.

      1. Anonymous Coward
        Anonymous Coward

        Re: No excitement in most cases, unfortunately

        "send the appropriate number of elections down it"

        Now, now Donald. Biden won fair and square.

        1. Sorry that handle is already taken. Silver badge

          Re: No excitement in most cases, unfortunately

          Uhh... that was a weird mistake.

        2. Ken Moorhouse Silver badge

          Re: Now, now Donald. Biden won fair and square.

          "Not if they were mail-in electrons he didn't."

          D. Trump.

    7. DS999 Silver badge

      This isn't actually more amps

      This is 5A @48V, previous versions maxed out at 100 watts which was 5A @20V, so no greater risk of fusing the cable.

      In addition, USB-C requires active cables to enable 5A power delivery, otherwise it is limited to 3A, so no one should burn down their house with 240 watt PD using a cable not designed to carry that much power.

  4. Boothy

    Do OnePlus still use a proprietary fast charger standard, rather than USB PD?

    I've got an old OnePlus 3, it's USB-C, but you can only fast charge if using their provided charger and cable, use a USB PD charger, or a different cable, and it just trickle charges.

    Does anyone else do that?

    I've no issue per say with them using some other standard, but that really aught to be in addition to USB PD, rather than instead of.

    As it stands now, it means you still end up with two sets of chargers and cables, if you want to cover fast charging, even though both, or more, devices are USB-C.

    1. Me too

      RE OnePlus Warp Charge 30

      As far as the Nord at least, yes. Warp Charge 30 just makes 6A available at 5V instead of upping the voltage to keep the current to reasonable levels. Maybe it's cheaper to do that than pay for the licensing to do USB PD.

  5. Anonymous Coward
    Anonymous Coward

    I wish they fixed the hub issue

    Annoyingly, at present you can't really get a USB-C to USB-C only hub, so you're still stuck with a mix of USB-C and USB-A connectors.

    Not as complete a migration as I'd hoped for..

    1. Mishak Silver badge

      Re: I wish they fixed the hub issue

      Intel are supposed to have released a device to allow USB-C only hubs to be produced. Not seen one yet...

    2. Danny 14

      Re: I wish they fixed the hub issue

      USB-C docking stations come close. they come with other cruft though and mess with the host device (adding VGA, network and sound etc)

  6. Anonymous Coward
    Anonymous Coward

    hope it's enough

    In theory USB-C can provide power transfer in both directions.

    But I recently purchased an electric car, and even plugging in chargers to both the USB-C ports in the car seems to have virtually no effect topping up the car's state of charge.

    Fortunately it looks like there is a filler cap hatch on the outside body of the car, so I am guessing for now I can just add some petrol until they can get this charging business to work.

    1. Anonymous Coward
      Anonymous Coward

      Re: hope it's enough

      OK, I'm not at a stage yet with my phone that I need a car-sized electric generator to keep up with the charging :)

    2. Danny 14

      Re: hope it's enough

      funnily enough, a rep was at our work last week, he had a BMW i8. Those are quite interesting beasts, fully electric on the front with a small petrol engine on the rear. I had never seen one up close before and they look pretty good.

  7. Andy The Hat Silver badge

    240W?

    Hell that's (clickety clack> 48A at 5V!

    Having a connector that delivers that is one thing - though I can't believe the current USB-C standard connector style is adequate for that after a couple of insertions and some pocket fluff on the connector - but designing a cable that's anything longer than a pigtail which will deliver 48A whilst coiled up, laying under a book on a desk next to a radiator without overheating or giving excessive voltage drop...? There is no diversity to allow for here (as interchangeability between devices is key) so the cable has to be able to deliver maximum power (48A) whatever the configuration. Under the standard UK wiring regs, 4mm2 cable would be pushing it in free air but assuming that size and the connector able to physically support the weight, at 48A the cable voltage drop alone of a 1m cable (is that a reasonable maximum length?) would be 1.68e--2*48x2=1.6V ... so the maximum voltage of any connected appliance has to be assumed as 3.4V (without building a buck psu into each device) ... is that feasable?

    Seems to me this may be a standard which is technically possible but may not be that useful in a practical context - a wall wart will be replaced with an internal buck boost supply in every device which means bigger devices and far less efficient power delivery due to the cable losses. If all devices are natively 3V DC or less it would be ok but is that possible? Am I missing something?

    1. Spoobistle
      Facepalm

      Re: 240W? Music power!

      This new spec allows up to 48V, so that would be about 5A. Just hope the "negotiation" doesn't go wrong or you could have a whole new lot of light emitting diodes, transistors, resistors etc in your teensy device.

      Anybody remember Music Power? This was a rating that enabled fag packet size speakers to do 50W. I can just see the cheapskate tat-floggers putting out tinsel cables rated for "240W (Do Not Use for More Than 3 Seconds)". Then we'll doubtless get stories like "My Nan always crochets matinee jackets for our tech, how should we know it was going to catch fire while the cat was lying on it..."

      1. Andy The Hat Silver badge

        Re: 240W? Music power!

        Wasn't aware of voltage negotiation in the spec ... from experience I'm not sure if that makes it better or worse. I had a battery charger with it's charging terminals contacts floating at 240Vdc. After the initial shock (sic) I discovered all was well and good as the charger automatically detected the battery terminal voltage and set the output to the required charging characteristic ... until in this case it hadn't. Which is why I had it on my desk along with a battery with its arse blown off ...

    2. katrinab Silver badge
      Paris Hilton

      Re: 240W?

      100W is 5A x 20V. I presume they will be upping the volts rather than the amps?

    3. Anonymous Coward
      Anonymous Coward

      Re: 240W?

      Hey, you must admit that a USB-C power supply would be even more universal if you could also weld with it :).

      Somehow I don't think this will happen at 5V, though. As cables signal themselves what they're capable of there's also scope to further up the voltage so you keep the amperage down.

      In effect, that's what QC3 phone charging does with "regular" USB cables - if it cannot find a QC3 compatible device on the other side it will simply stick to 5V to prevent toasting anything else that users may plug in.

      1. Roland6 Silver badge

        Re: 240W?

        >Hey, you must admit that a USB-C power supply would be even more universal if you could also weld with it :).

        Somehow I don't think this will happen at 5V

        Never tried arc welding with a Durcell AA battery? The arc produced is sufficient to melt solder.

        Which would indicate that hot swapping of these new USB-C cables is not to be recommended...

    4. Dave559 Silver badge

      Re: 240W?

      Heck, anything that requires certain power cables to be a bit beefier and stronger can only be a good thing. Why, yes, I am writing this as someone whose current weedy MagSafe2 cable has got to the terminally fraying/disintegrating stage, again (and these are stupidly hard-wired into the transformer part, rather than being a sacrificial removeable/replaceable cable). Apart from the actual MagSafe connector, the functional design of these PSUs is appallingly dreadful (their UK mains plug also has effectively no hand grip on it, and so is very hard to unplug, because it's not as if you would ever take a laptop on the move with you, would you?).

      It's ridiculous that these are punier and a worse design than decent phone charging cables, which are only fractionally thicker, but are now mostly designed and made with a braided cable outer to make them much stronger and long lasting. This really is incredible advanced technology, well, apart from having been used in power cables for irons for donkey's years…

      If Apple are, as rumoured, going to be reinventing the MagSafe cable, let's hope they actually get it properly right this time (although, to be honest, I'd now much prefer being able to use a relatively standard USB-C cable + magnetic adapter for power on either side of the laptop, depending on where the nearest suitable wall socket is).

      1. katrinab Silver badge
        WTF?

        Re: 240W?

        I checked my extensive collection of UK plugs, including two the ones on two magsafe chargers from 10ish years ago, and they all have effective hand grips on them. Certainly, I have never struggled to pull a UK plug out of a UK socket.

        1. Dave559 Silver badge

          Re: 240W?

          Hmmm, maybe Apple changed the design at some point? Mine is for an 2015 MBP, and the plug (on the supplied plug to transformer cable) is only about half as thick as a normal UK plug, has completely smooth vertical sides (rather than the concave finger recesses that standard(?) plugs have), and is a very tight fit into the plug socket, all of which do conspire to make it (unnecessarily) hard to pull out!

          1. Anonymous Coward
            Anonymous Coward

            Re: 240W?

            Replacements for those are available in abundance on Amazon and the like, so if it really bothers you, change it.

            Or get a typical main cable for a radio or something that end sin a figure eight type plug. Unplug UK plug from PSU, plug in power lead and off you go. Also super handy for when you're abroad and forget a power socket adaptor, most places have those spare.

            1. Roland6 Silver badge

              Re: 240W?

              Up voted another solution to a problem I've been having with users who have poor grip and so are unable to hold the dimpled plug with sufficient force to remove it from the socket.

              I've typically glued a finger handle onto the power adaptor.

      2. Anonymous Coward
        Anonymous Coward

        Re: 240W?

        Personally I found that one of the most massive benefits of moving to USB-C power: finally I can just rip a frayed cable out and replace it with a new one instead of having to replace the whole device (or opening it and re-solder the cable). Heck, I can even use a non-Apple power supply.

        Apple also finally dispensed with the stupid lugs on the power supply which were a great invitation to destroy the power cable sooner by actually using them and winding the cable around those sharp edges. Not their best idea IMHO.

  8. Mike 137 Silver badge

    Dissipation?

    @Andy The Hat

    Good point about the cable voltage drop, and you'd need at least 2.5 mm2 cores to carry 48 amps safely. (c. 2 kA/cm2).

    However quite apart from any cable, at the 50 milliohm specified maximum contact resistance, there's going to be quite a voltage drop at the pins. There are four connections for VBus and four for GND, so the maximum loop resistance for the entire connector is 50x2/4 = 25 milliohms. Assuming VBus is at 5V, the total dissipation in the connector will be 482x0.025 = 57.6 watts, each connection dissipating about 7 watts. It's going to get hot.

    1. Fred Flintstone Gold badge

      Re: Dissipation?

      I think you may have just plausibly suggested that new chipsets for this may include a mandatory temperature sensor. I don't think that would be a bad idea anyway.

    2. Anonymous Coward
      Anonymous Coward

      Re: Dissipation?

      "Assuming VBus is at 5V,"

      Why would any sensible person assume that? Clearly lots of commentards here seem to think it will be the case, I am seriously *hoping* that they are wrong.

    3. Cynic_999

      Re: Dissipation?

      Except it doesn't need to carry anything close to 48 Amps. If both device and PSU signal that they are capable of operating at the higher power levels, they switch to a higher voltage in order to deliver the high power with a lower current. At 48 volts, 240 watts will require the cable & connector to pass 5A of current.

  9. Pascal Monett Silver badge
    Thumb Up

    Wow

    The amount of geekery in this thread is impressive.

    I would have thought that a 700+ page specification would be a guarantee of thoroughness and reliability - after all, this is not Borkzilla wat wrote it - but apparently there are a number of more intelligent people than me that have a lot to say about it.

    El Reg is the best.

    1. Anonymous Coward
      Anonymous Coward

      Re: Wow

      Also, specifications only specify.

      They rarely explicitly focus on what ingenious but dumb users can get up to (in my experience a lethal combination), nor do they poke fun at themselves.

      That's our job :).

    2. Roland6 Silver badge

      Re: Wow

      >I would have thought that a 700+ page specification would be a guarantee of thoroughness and reliability...

      Given the history of the UK 3-pin plug and socket Standard, the question that has to be asked: how many women were on the committee and had their contributions accepted...

      1. Anonymous Coward
        Anonymous Coward

        Re: Wow

        What does the gender of the committee members have to do with it?

        1. Roland6 Silver badge

          Re: Wow

          Read the history of the UK 3-pin plug!

  10. mark l 2 Silver badge

    While I see that having the ability to delivery 240W is handy. I do feel like its every other week we get some change to the USB specification. We had 4 revisions to the USB power delivery specification between 2017 and 2019 and now another just announced in this article. (And that is not even taking in to consideration all the different specs for bandwidth that they have released).

    Do those proposing these updated specifications not try and think ahead for more than a couple of years of what people will be wanting on there devices?

    1. Ken Moorhouse Silver badge

      RE: Do those proposing these updated specifications not try and think ahead...

      You are aware that USB stands for Unique Selling Bonanza?

  11. Red Ted
    Go

    We need more power, Igor!

    *Cackles Manically* and throws over the metal-and-bakelite knife switch...

  12. Terry 6 Silver badge

    USB confusion

    These are consumer devices. Sadly the labelling and descriptions of the various assorted USB connectors already around is so appealingly confused, if not to say obfuscated, that I just have a bad feeling about this.

    PCWorld magazine, funnily enough had a column on this a week or two ago. It's even more confusing than I'd realised, and that was very confusing.

    1. Anonymous Coward
      Anonymous Coward

      Re: USB confusion

      I only have that on Monday mornings before coffee :)

    2. WolfFan Silver badge

      Re: USB confusion

      Hmm. Do you have a URL for that? A quick look at the site doesn’t show it.

      1. Terry 6 Silver badge

        Re: USB confusion

        Sorry, no, recycled already. And it will be buried within a column, alongside other comments. That being the house style or something along those lines, I think.

        1. WolfFan Silver badge

          Re: USB confusion

          Thanks anyway.

  13. Blackjack Silver badge

    USB-C cables are not exactly durable... While yes is almost freaking impossible to fix a charger port of a laptop unless is a very generic port, the charger itself does tend to last more that the actual laptop to me.

    1. Roland6 Silver badge

      >USB-C cables are not exactly durable...

      Nor are the USB Type-C sockets that some many devices fit these days...

  14. Elledan
    Happy

    What's this 'USB-C'?

    I think I may have a USB-C port on the laptop I bought in 2019, but I'd have to check to make sure as I haven't used it yet. I'm honestly more bothered about having enough USB-A ports on my laptops so that I can actually plug in USB sticks, mice and external keyboards without dumb dongles.

    I think I'd prefer a standard barrel jack configuration for laptops over using USB-C with USB-PC, but whatever incinerates your USB cable, I guess?

    1. Roland6 Silver badge

      Re: What's this 'USB-C'?

      >I think I'd prefer a standard barrel jack configuration for laptops over using USB-C with USB-PC, but whatever incinerates your USB cable, I guess?

      The outstanding advantage of the standard barrel jack connector is that there is no confusion as to which port/'hole' it goes into.

      I've found that many laptops only have one USB Type-C port that will take the power adaptor; when the laptop has to the casual user an identical USB port in identical positions (last port to the rear next to the screen hinge) on either side of the screen users will plug the power cable into either port and then complain their laptop isn't charging. I 'solved' this problem by the use of magnetic USB adaptors to make it obvious which (USB) port the power adaptor is to be plugged into (it also helps to prolong the life of the port).

      I have similar issues with devices that have both USB 2 and USB 3 ports, plug in a USB 3 capable device in a USB 2 port and whilst the message informing me that I should use a different port to get best performance, its of little real help as Windows has proceeded to mount the device and the message gives no assistance (to non-IT users who don't remember the blue tab marking of USB 3 ports) as to which of the other USB ports might be faster.(*)

      (*)This raises a question as to whether this new USB standard has introduced new port colour codings...

  15. DS999 Silver badge

    "One charger to rule them all"

    The sad thing is that if a phone supported a 240 watt charger some idiots would trumpet that as an advantage of that phone, while pointing and laughing at phones that could support "only" 30 or 60 or whatever more reasonable number of watts today's fastest charging USB-PD phones support.

  16. Paul Hovnanian Silver badge

    Phones are not Laptops

    I understand charging a phone via the available USB port. Real estate for ports is precious on phones but the power requirements are not high.

    Laptops have more room for additional ports. So why a serial bus port for these levels of power? Why not come up with a universal power port more suited to these levers of voltage and current (I ask facetiously)? Like all the iGo/Targus configurable power bricks that ended up in a landfill because laptop manufacturers had to tweak the interface just enough to make them not work? Or worse yet, the software handshakes between proprietary power supply, battery and laptop that could disable charging with a firmware revision when the vendor decided it was time for you to buy new kit (Dell, I'm looking at you).

POST COMMENT House rules

Not a member of The Register? Create a new account here.

  • Enter your comment

  • Add an icon

Anonymous cowards cannot choose their icon