
Digitec GaN 4-Port Fast Charger
240 W
Digitec GaN 4-Port Fast Charger
240 W
I have the digitec GaN 4-Port Fast Charger 240W charger with a Vivanco 240W cable (https://www.galaxus.ch/de/s1/product/vivanco-longlife-usb40-c-c-kabel-metallstecker-u-nylon-geflecht-5a-240w-schwarz-20m-2-m-usb-40-usb-k-39527946?supplier=4867603) and would like to use it to charge my Dell XPS 15, which requires 130W. According to the specifications, port 1 of the charger should deliver 140W, yet my laptop says I have a slow charger connected. Am I doing something wrong? Thanks for the help!
I don't have the described laptop myself, but from what I read on the Internet, the laptop cannot be charged via a charger with 130W according to USB specifications...
The 130W Dell "USB-C" AC adapter (https://www.digitec.ch/de/s1/product/dell-usb-c-ac-adapter-130-w-notebook-netzteil-24661326) delivers an output current of 6.5A according to the specification. 6.5A x 20V then gives the 130W. However, the USB C specification limits the current to 5A in any case, as the cables and plugs are not expected to deliver more.
This is probably a case of "manufacturer overtakes specification on the right". When USB Power Delivery (PD) was introduced, the power was limited to 100W (5A x 20V). Dell probably wanted / needed more and bent the specification a bit (Dell will probably say that a specification-compliant alternate mode has been implemented - but this does not change the fact that a standard power supply according to PD version <=3.0 cannot deliver 130W). Since May 2021 and USB PD version 3.1, higher voltages (up to 48V) and thus 240W can be supplied via USB C with "Extended Power Range" (EPR) and with suitable cables. This is exactly what the digitec Charger delivers on port 1: 5A x 28V = 140W. However, the current remains limited to 5A even with the latest specification - and the power is therefore limited to a maximum of 5A x 48W = 240W. Dell is still outside the specification with its 6.5A and 130W (see e.g. https://www.reddit.com/r...).
In short: You have done everything right, but unfortunately you still need the Dell power supply to be able to charge at the maximum speed, as Dell does not adhere to specifications.
Unfortunately, I was unable to find out whether your laptop charges with at least the standard-compliant 100W (5A x 20V) with the charger you purchased. At least with the early 130W "USB-C" laptops, not even that seemed to work (see e.g. https://www.reddit.com/r...).