Powerbank for Latitude 7480 (USB-C)

Thanks very much for the detailed reply @jphughan! That 100% makes sense that the 19V delivery is through the DC connection and not USB, which was my fear of getting a USB-A to USB-C adapter. It seems in most implementations in order to push power the connection is USB-C on both ends, and the PD requirement, which is fairly recent (last couple of years).

Would you know if Dell 7480 still checks if the battery/charger is manufactured by Dell? I've used Lenovo mostly, but previous Dell laptops I had would power on from generic power supplies, but not charge the batteries. Is that still the case with USB-C PD?

@Groovechild308  happy to help!

In terms of checking the manufacturer of the power source, there is mostly good news here overall and all good news since you’re using a 7480. USB-C uses the USB PD standard to handle charging, which is an industry wide standard. That means that as long as your power source supports USB PD and can provide voltage and total wattage levels that your laptop will work with, then you’re good to go. I have USB PD sources from 3 different non-Dell vendors and they all work with all of the Dell and Lenovo laptops in my home (and other non-laptop devices) — including my Latitude 7480.

The 7480 is designed for a 65W source, so you’ll want a 60W or 65W USB-C charger. The former is much more common to find because exceeding 60W also requires using cables rated for up to 100W, which are noticeably thicker. Most people aren’t willing to deal with that for an extra 5W, so 65W sources are rather rare — although I do have one made by Nekteck, and it works at 65W when you have a 100W cable, otherwise it only provides 60W. But the 7480 will work just fine with a 60W source WITHOUT throwing a warning about an undersized power adapter. As for voltage, to be safe you want a source that supports up to 20V output when you’ll be using it with laptops, but any 60W+ source will. The 45W sources are less certain since some of them only support that output as 15V at 3A rather than also offering 20V at 2.25A, which limits their compatibility. But since 60W sources aren’t much larger or expensive, I don’t see a point to getting 45W sources anyway.

If you’re curious, the reason I said “mostly good news overall” is that as of this writing, Dell systems will not draw more than 65W from non-Dell USB-C power sources, even if the source provides more and the system is designed for more. This doesn’t matter for you since the 7480 is only designed for 65W anyway, but it comes into play with systems like the XPS 15 models that are designed for 130W. The recent generations of that system will draw the full 130W over USB-C using DELL’s 130W USB-C adapter (Dell did something proprietary to stretch the official USB PD spec a bit, since that maxes out at 100W), but for example I also have a Nekteck 90W USB-C power source. It’s recognized as a 65W source with an XPS 15, even though my ThinkPad X1 Extreme designed for a 135W power source sees it as a 90W source. That’s a bit annoying for the XPS 15 because it’s now drawing only half the power it’s designed for, which means it will do things like reduce battery charging speed and even CPU and GPU performance to compensate for the power shortfall. Of course 90W isn’t as much as that system is designed for either, but it’s almost 50% more than the system is choosing to draw, so even 90W would allow for better performance and battery charge speeds than only drawing 65W. I’m not sure why Dell has added this limitation on their current systems, but there you go.

astounding I just recently bought one of these Dell machines and was wondering how a USB -c charger could work  period as I was searching to buy a needed charger batt. set for it while I anticipate it's delivery in the mail, and this answer is,  was very clear and thorough thanks tech.  but how bout an update for 2024 is this technology still the same as was dec.2019?

after reading the reply on the bottom I'm educated, you Dell guys are pretty good , and have restored my lost faith in the corporate technological stream for now thank you both for ? and answers sincerely..  B. B.