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January 25th, 2019 13:00

Dell XPS 13 Charging Adapter

Hi guys, so i have a question relating to the dell xps 13's 45W slim USB C charging adapter... 

I've just purchased a USB C hub with power-delivery and a passthrough of 87W. Does this mean that i can directly connect my current dell-supplied charging adapter to this USB C hub and it will charge the laptop with only using 1 cable? 

Also, on a similar note, if i want to get a different USB C laptop charger for my XPS laptop, could i purchase a higher wattage charger? Or would this affect the laptop in a bad way?

Thanks guys :) x

(Dell XPS 13 9370)

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January 25th, 2019 14:00


@AlexShields1 wrote:

Hi guys, so i have a question relating to the dell xps 13's 45W slim USB C charging adapter... 

I've just purchased a USB C hub with power-delivery and a passthrough of 87W. Does this mean that i can directly connect my current dell-supplied charging adapter to this USB C hub and it will charge the laptop with only using 1 cable? 

Also, on a similar note, if i want to get a different USB C laptop charger for my XPS laptop, could i purchase a higher wattage charger? Or would this affect the laptop in a bad way?

Thanks guys :) x

(Dell XPS 13 9370)


Yes, the purpose of a USB-C hub (or "mini dock" depending on the ports it has) that supports USB PD passthrough is to allow you to connect your laptop charger to that device and then plug only that device into the system.  It's especially popular on systems like the regular MacBook, which has just a single USB-C connector.  However, the hub/docks will typically draw some power from the power adapter for itself when one is connected (rather than pulling the required power from the system), so if your laptop is designed for a 45W adapter and you're using a 45W adapter through the hub/dock, your laptop won't be getting the full 45W.  That may or may not trigger a warning on the system about an undersized power source.  It might depend on exactly how much power the hub/dock itself takes.

One other note about those devices.  If the power source changes while the hub/dock is connected, i.e. because you either connect or disconnect the laptop charger, that might cause the dock's USB ports to reset so that they start drawing power from the other source in order to provide it to whatever you plug into those ports.  So if you're in the middle of transferring a file to an external hard drive that you've connected through the hub/dock, that wouldn't be a good time to connect or disconnect the laptop charger.

In terms of other charger options, you can absolutely buy a higher wattage USB-C power adapter and it will be fine.  The laptop will only pull what it actually wants.  However, make sure you buy a good charger, because in the early days of USB-C chargers, several were found to have bad designs that could damage electronics and even create a fire hazard.  Google "Benson Leung USB-C" if you're curious.  Looking for chargers that are certified by UL and/or USB-IF is a good start.  I just bought a Nekteck 65W USB-C charger, which carries both certifications, and it works perfectly with my Latitude 7480, my wife's XPS 13 9350, and my wife's Lenovo T480.  I also bought a Nekteck 10ft USB-C cable because the charger only comes with a 6ft cable, and I realized our regular laptop chargers all offered 9ft of total cord length.  And this won't matter if you're only using 45W, but be aware that there are two levels of power support for USB-C cables.  All USB-C cables must carry at least 60W / 3A, but if you want more than that, you need to buy a cable rated for up to 100W / 5A.  When I plug a USB-C cable only rated for 60W into my 65W Nekteck charger, my Latitude 7480 only negotiates 60W, even though it negotiates 65W with a 100W cable.  (Note: USB Power Delivery maxes out at 20V, so 3A and 5A give a total of 60W and 100W, respectively. The reason the rating is sometimes provided in amps is because cable design has to take amperage into account, but not voltage.  Technically the amp rating is more correct, since if the USB-PD standard were revised to allow higher voltages, those cables would carry it just fine and therefore support higher wattages, but most people know the required wattage of their system rather than the required amperage, which is why you'll find that rating as well.)

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