XPS Developer Edition 7390 not charging from Belkin Thunderbolt 3 dock

@TheseusLinux  if you haven't already, make sure you're running the latest BIOS release on the XPS 13 and the latest firmware for the dock in case this is some sort of firmware-level interoperability bug.  If that's not it, then considering that you've already confirmed the system charges from multiple other devices, this might be a question better posed to Belkin.  The XPS 13 models are designed for a 45W power source.  They normally pull that as 20V at 2.25A, but I remember someone reporting that they could draw 45W from a power source that only supplied up to 15V output, which would have been 15V at 3A.

Also, when you have the dock connected, does the OS show that a power source is connected but that the battery isn't charging, or does the system not register an attached power source at all, i.e. the battery continues DIScharging?

Based on your description, it sounds like the Dell dock you're using is the WD15.  The model is on a sticker located on the underside of the dock, near the upper-right corner of said sticker.  That dock can supply either 90W or 130W to attached Dell systems, depending on whether the dock itself has a 130W or 180W power source connected, or 60W to non-Dell systems.  However, the WD15 is a regular USB-C dock, i.e. non-Thunderbolt, and since it also only supports DisplayPort 1.2 over USB-C from source systems, it can only run a single 4K display at 30 Hz (or a single 2560x1600 display at 60 Hz, or dual 1920x1200 displays at 60 Hz), whereas Thunderbolt 3 docks can run dual 4K displays each at 60 Hz.  The Thunderbolt equivalents of the WD15 and WD19 are the TB16 and WD19TB, respectively.

As for third party dock recommendations, given that the XPS 13 has relatively modest power requirements and supports Thunderbolt 3, pretty much any USB-C or TB3 dock should work.  A friend of mine uses the CalDigit TS3+ dock with both his XPS 13 and 13" MacBook Pro and doesn't have any issues, and it supplies up to 85W, which is enough for a 15" MacBook Pro.  Don't worry that the 85W output is 2W short of the 87W from the MBP's normal charger.  The missing 2W won't make a practical difference, the MBP can operate from lower wattage sources if needed, and the 87W actually comes from Apple using a USB PD charging profile that isn't compliant with the standard (slightly more than 20V output).  In fact the Apple 87W charger doesn't support some standard USB PD charging profiles (like 15V output), which makes it a lot less useful than it could be since it prevents some other standards-compliant devices from being able to charge from it properly.

Anyway, my friend connects one of his displays to the CalDigit dock via DisplayPort and the other to the dock's USB-C port using a USB-C to DisplayPort cable.  But again, I'm not sure why your Belkin dock wouldn't be able to charge the XPS 13.

Looking more closely at the bottom of the Dell dock it is indeed a WD15.

Near as I can tell the battery is discharging as there is not lightning indicator as there is with the WD15 or the supplied charger.

I don't own another Thunderbolt 3 dock so maybe this is an issue with all Thunderbolt 3 docks or just the Belkin dock.  I do know that the Belkin dock does supply power to my Latitude as well.

It wouldn't be an issue with all Thunderbolt docks because Dell and others make Thunderbolt docks that charge systems just fine, including the XPS 13 models.  As I mentioned, my friend is using a CalDigit TS3+ Thunderbolt dock that's charging his XPS 13 and 13" MacBook Pro just fine.  And Thunderbolt vs. regular USB-C makes no difference for charging anyway because both of them use the USB Power Delivery spec.  Power is handled on a completely separate communication channel and over a completely different set of pins than are used for Thunderbolt or regular USB-C video/USB 3.x traffic.

Hi!

I have this issue with 9570 now too. It is started with latest BIOS or WIN10 updates. I have I-Tec power adapter. In BIOS I can see, that there is 65W input, but discharing. Before updates was all ok.

Pavel

I have no idea if this is an issue with:

1. Only the Belkin TB3 dock

2. All 3rd party (non-Dell) TB3 docks

3. All TB3 docks (including Dell's)

I wish there was a cheap way to find out.

@Pavel XPS  the XPS 15 9570 is designed for a 130W power source, and Dell systems currently limit themselves to drawing 65W over USB-C from non-Dell sources, even if the power source can provide more and the system would benefit from more.  I have an XPS 15 and a Nekteck 90W USB-C charger, for example.  My Lenovo system recognizes it as a 90W power source, but the XPS 15 only recognizes it as a 65W source.  If you run a system from an undersized power source, you can experience behaviors like slow battery charging and significantly throttled CPU and GPU performance as the system tries to operate within the reduced power budget.  And under very heavy load cases, as a last resort the system will continue draining its battery to make up for the power shortfall if all of the throttling measures it tries first still don't allow it to work within the constraints of the undersized power source.  In your case, you're operating with only half the power the XPS 15 is designed for.  None of this is the result of a recent BIOS update.  This has been true of Dell systems in general for years, including previous generations of the XPS 15.  And a Windows update wouldn't have been a factor since charging is handled at a system firmware level, not an OS level.

The additional wrinkle with the XPS 15 is that its 130W power target is above the 100W max of the official USB Power Delivery spec.  Dell did something proprietary on some of its docks in order to stretch the spec to deliver 130W to such systems, but you won't find that implemented anywhere else.  The current generation Dell docks that would provide 130W to that system are the WD19 with 180W power supply (not the 130W power supply it can also be ordered with) and the WD19TB (comes standard with 180W power supply).  The latter uses Thunderbolt 3 and can therefore support higher-end display setups than the former, which uses regular USB-C.  If you don't want to use one of those docks, you should keep the system's 130W AC adapter directly connected in addition to the dock in order to maintain proper performance.

Hello, I understand about this - I know that 65W is max for this chargers via USB-C. It is ok for me. I have high voltage work only few times in office (where I have this charger hub). Problem is that BIOS and Windows know about charger and 65W voltage input, but for all time is discharging. Before updates was all ok, and there was only "slow charging" - but I could run for all day in my work, without drained battery - now with charger I have only ~6 hours - because as source of power is battery only.

And  - I think that BIOS is very low-voltage enviroment - so why I can see now that input is 65W but discharging?

@Pavel XPS  I'm not sure why the BIOS would be identifying a 65W power source and would still be discharging rather than charging.  I haven't seen that myself.  As one admittedly long shot idea, one thing you can try is reflashing the same BIOS you're already running.  I know that sounds unlikely to make a difference, but I once had an XPS 13 where I updated the BIOS and the system said it was successful, but several weeks after that I noticed that when I put the system to sleep, it would completely cut power, causing the system to start from scratch afterward and of course causing me to lose everything that was open when I put the system to sleep.  I don't use Sleep often, so I didn't immediately make the connection to the BIOS update.  Instead I spent a bunch of time checking drivers, BIOS settings, etc., and right when I was about to wipe the hard drive and reinstall Windows from scratch, I remembered the BIOS update.  I wondered if just reflashing it might fix anything.  I didn't actually think it would, but I figured spending 2 minutes doing that was worth it before spending multiple hours rebuilding my system.  The reflash fixed the problem.

Or of course you could try downgrading back to whatever BIOS release you were running before unless the new version has some other fix or enhancement you really need.

BIOS was reflash due to support team request. No change. Second problem what I have (maybe had) is sleep mode as you. From re-flash it is maybe ok, I will know after some more time.

Hi, new bios have fixes with usb-c power-delivery. So problem is on your side. But after update - charger not charging battery still. Today I will have change motherboard in warranty - so will see.

New MB was bad - LCD backlight did not work ... no more DELL, sorry.

But charging on this MB was ok - BIOS v1.13 there.