USB-C cables power vs plug power

Posted 25th Nov 2022 (Posted 13 h, 11 m ago)

I bought a 25W Samsung plug + usb c cable. This cable, when used with a 65W plug, can somehow charge my laptop. And separately I bought a 100W Baseus usb c cable which charges my laptop at same speed. So does the "100W" cable advertisement mean anything? Or are they all able to carry the same power?

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12 h, 27 m ago
Yeah it's what the cable is saying it can safely carry up to, you wouldn't want to put 100W of power over a cable that can only carry 5V/3A for risk of melting and potential fire, with Power Delivery I think there is smarts in the chargers and cable to prevent a charger putting out more power than the cable can take however this relies on using reliable cables/chargers and I would always manually make sure I'm not trying to charge a high power device with a lower Watt cable

Most outputs on the chargers will be a maximum of 3A and only the voltage changes to get the higher W output, this makes it safer for all cables, the Baseus 100W cable can carry up to 20V at 5A for compatible chargers and devices (edited)
8 h, 20 m ago
100w and above cables have an e-marker chip to announce they can handle the current. The laptop will just charge at up to 65w. If you connect it to a 100w charger (and the laptop can charge at 100w), you'd only get 65w from it so it would charge a bit slower.
2 m ago
IIRC the USB-C spec says all cables should be built to carry 3A. That translates to 60W if connecting a device and power supply that both support USB-PD's 20V mode.

It also optionally allows a cable to be built to carry 5A, although that cable has to be equipped with a chip to tell the devices either end that it's capable of this. If that marker isn't present then the devices will only transfer a maximum of 3A.