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by coldtea 91 days ago
>No need to overthink it. USB cables should just label themselves with their bandwidth - it's not rocket science.

And yet, this requirement already misses the other thing it should state: it's power rating. Because even two cables with the same bandwidth can have widely different power rating, and thus powering capacity or charging speed for different devices.
2 comments
ssl-3 91 days ago
I have no respect for a man who can't label a cable with more than one figure.
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Dylan16807 91 days ago
Don't take this comment too seriously, just a curiosity.

Powering capacity sometimes matters, but are there any devices out there where the charging speed would be meaningfully different? As in, they use significantly more than 60 watts to charge? (I looked up some of those super fast charging phones and they don't seem to be following the USB standards in the first place.)

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masklinn 91 days ago
> but are there any devices out there where the charging speed would be meaningfully different? As in, they use significantly more than 60 watts to charge?

Any device which can charge at 100W or more? Like lots of laptops, as well as my ebile batteries?

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zimpenfish 91 days ago
> Like lots of laptops, as well as my ebile batteries?

Soldering irons can benefit from being able to peak above 60W when heating.

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ssl-3 91 days ago
They certainly can.

A dainty little USB-powered Pinecil v2 can peak at ~126W with appropriate firmware and an EPR 28v PD 3.1 power supply. It's an impressive feat. :) (And, yes, it requires a USB cable that is e-marked for 240W before this is allowed to happen.)

That said: 28v EPR is a bit usual. A more typical configuration runs on 20v USB PD at no more than ~64W, like a cheap, genuine [safe], used 65w Lenovo laptop charger cheerfully provides.

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Dylan16807 90 days ago
The question was about charging.
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Dylan16807 90 days ago
"Lots of" laptops? Upon searching a bit harder I think the 16 inch macbook pro can probably do it. Most laptops that can hit 50% in half an hour don't have a big enough battery to charge at much over 60 watts.

Ebike is interesting.

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masklinn 90 days ago
> Upon searching a bit harder I think the 16 inch macbook pro can probably do it.

The 16" MBP can charge at 140W over USB-C since the M3 (before that it's limited to 100W over USB-C, Magsafe was required to hit 140), the 14" can charge at 100W (specifically 96W) over USB-C: https://support.apple.com/en-us/102378

Framework's 16" can charge at 85W (1C on an 85W battery), and it can also pull 160W from the charger under load (possibly under load + charging).

Getting clear infos from Dell is impossible but it looks like a number of laptops are provided with 130W chargers, and their "ExpressCharge" is apparently a bit under 1C, so their 96Wh battery expresscharge laptops likely charge around 85W (and require 130W chargers to do so).

etc...

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Dylan16807 90 days ago
I don't see anything about charging at 140W on that apple page. I do see it saying 50 percent in half an hour which is a lot less. For the 16 inch that's near 100W, for the 14 inch with an almost 70Wh battery that's about 70 watts.

I guess 85W is enough to make a difference from 60W, but it's pretty close.

> and require 130W chargers to do so

Only if that's a weird artificial requirement, no way charging is only 60% efficient.

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