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  • USB C - different capabilities and cables

    From David@21:1/5 to All on Sat May 6 14:31:38 2023
    I chanced across this: <https://www.amazon.co.uk/90W-Charger-Reavio-Compatible-Chromebooks-White/ dp/B0B7RWVQNG/>
    which is marked up as having two ports Type C1 and Type C2 each capable of
    45W.

    I then tried to look up exactly what this was and drowned in too much
    detail.

    So what are these two types, what cables would they require to deliver the marked power, what other options are there to deliver this power or higher?

    I am confused, apart from anything else, by having a fast charger for my
    Realme mobile phone which doesn't seem to fast charge anything else.

    I also think I read that the cables carrying the higher power levels need
    to be 1 metre (2 m?) long max.

    All very confusing.

    Cheers


    Dave R


    --
    AMD FX-6300 in GA-990X-Gaming SLI-CF running Windows 7 Pro x64

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  • From Theo@21:1/5 to David on Sat May 6 18:44:51 2023
    David <wibble@btinternet.com> wrote:
    I chanced across this: <https://www.amazon.co.uk/90W-Charger-Reavio-Compatible-Chromebooks-White/ dp/B0B7RWVQNG/>
    which is marked up as having two ports Type C1 and Type C2 each capable of 45W.

    I think the numbers are just marking ports 1 and 2.

    I then tried to look up exactly what this was and drowned in too much
    detail.

    Type C can carry USB-PD:
    5V up to 3A (marketed as a '15W' charger)
    9V up to 3A ('27W')
    15V up to 3A ('45W')
    20V up to 5A ('100W')
    28V up to 5A ('140W')
    36V up to 5A ('180W')
    48V up to 5A ('240W') https://en.wikipedia.org/wiki/USB_hardware#USB_Power_Delivery

    So a '45W' charger likely offers 15V, 9V and 5V. The device can choose
    which it prefers, so eg a 5V only device won't get more than 15W.

    So what are these two types, what cables would they require to deliver the marked power, what other options are there to deliver this power or higher?

    Up to a '45W' charger requires a 3A capable cable, higher requires a 5A
    capable cable. If the cable is marketed as '100W' then it should be able to
    do 5A.

    I am confused, apart from anything else, by having a fast charger for my Realme mobile phone which doesn't seem to fast charge anything else.

    As well as USB-PD there are also a panoply of proprietary fast charge protocols. Some like Qualcomm QC 2 just do the same steps as USB-PD, but others can offer power in fine steps - effectively this offboards the
    charging circuit and its heat generation from the phone into the charger. USB-PPS does the same in a standardised way.

    https://en.wikipedia.org/wiki/Quick_Charge

    The above suggests that Realme and Oppo use the proprietary VOOC protocol.

    I also think I read that the cables carrying the higher power levels need
    to be 1 metre (2 m?) long max.

    It shouldn't matter, as long as they put enough copper into the cable to
    carry the current - something cheapskate vendors don't like doing.

    Although VOOC has some weird stuff going on with the cable: https://en.wikipedia.org/wiki/VOOC

    Theo

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