Librem 14 - USB C charging

How does the USB C charging work? I kind of just figured it would be like charging my phone and just plugging in a USB C cable into the right port. I know only one of the USB C ports supports power delivery and the other is just for data. But which is which? I don’t see any labeling on the laptop for either and they look identical. So I just tested plugging in my charging cable into both ports and neither triggered the battery icon to update to indicate that it’s charging.

I notice in the tech specs page for the Librem 14 it states " 1 Port (supports Power Delivery sink for charging the laptop / Display Port alt mode, video output up to 4k @ 60Hz)". Is there some toggle to switch between power delivery and using it as a display port or is that automatic?

its the port on the right side of the laptop. The power delivery source needs to be able to negotiate and provide enough power for the laptop. I don’t think your standard phone charger would be able to provide enough power.

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Ahh, yeah I was wanting to use my solar backpack battery to charge my laptop and it does seem to work if I use the correct port on the battery.

Ha :slight_smile:
A solar panel would be great, indeed!

But type-C so called “Power Delivery” (PD) is not as simple as former USB charging where the source just provided 5V DC and was done with it - eat or die. PD is very complex and like it was already mentioned here requires the source and the sink to negotiate the terms, the negotiate a so called “contract”, where the source tells the sink which different voltage levels it can provide and also at which rate (current). Then the sink, in this case the laptop, picks one that suits best and confirms this back to the source. If both are happy, current flows.

In the case of the Librem14 the source needs to be able to provide at least 19V voltage, else it will not work at all. The current should total up to about at least 40W to 50W as a minimum, the DC charger that comes with the laptop provides 65W and the battery charger and power consumption control is tuned for 65W, so I would recommend a type-C source with 60W or more.

Cheers
nicole

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Could I use a power brick from the Mac Book Pro that I charge via USB3?

as above, you need a USB-PD charger which can supply 3A @ 20v minimum. If your MBP charger meets that, then yes. If it’s below that, it may charge, just less quickly.

Well, I tried it and my Mac Book Pro USB C chargers works with my Librem 14!

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Caveat on USB C charging. If I leave it plugged in and sleeping with USB C charging, I can’t get it to wake up and so I end up rebooting it.

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have not seen/heard of this before, will have to investigate

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I’m not able to reproduce this here, what firmware, OS, kernel, etc are in use?

Hi all! Has anyone found a good external battery for the L14 via PD that also works for phones / etc? Loving the machine and happy I made the L14 purchase. Thanks for the hard work, librem team.

I have some issues regarding the charging of my Librem14 via USB-PD. I am using the right USB-C Port, which is the one with USB-PD support. Are these known, is there are fix available or planned? Maybe someone from the staff can say something about this? @nicole.faerber

The first issue applys to 3 of the 5 chargers I tested:

  • Plugging the charger in while the Librem 14 is powered of, does not work (the Laptop is not charging).
  • You can get it to charge while it is turned off, by connecting the cable while it is turned on (booting is sufficient) and powering it down. This way, it keeps charging while it is turned off.
  • With all of these chargers, charging does work while it is turned on.

Second issue:
With one of those 3 chargers (the PinePower Desktop) I can see that when it is charging this way while it is powered off, it is only charging at 0.7-0.8 A @ 20V. So it is charging fairly slow.This is the case as well, when I close the lid of my Librem 14.
When it is powered on, I can see that it is charging at higher rates as well. But mostly when it is beeing used. So for example just beeing at the login screen, it only charges at about 1A @ 20V.

With this, I can also see why it isn’t charging when I plug the cable in while it is turned off:

  1. When plugging in the cable, while it is turned off, the displayed Volts change to 5.1V, while it stays at 0A. As the Librem 14 requires 20V, charging does not work.
  2. When plugging in the cable, while it is turned on, the displayed Volts change to 20V, it starts charging as well.
  3. When powering down now, it stays at 20V.

This makes it seem, like the USB Power-Delivery negotiation does not work correctly, when the Librem 14 is powered down.

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I can confirm, that both the “Anker PowerCore Elite III” and the “Anker PowerCore+ USB-PD” do work with the Librem 14, given the issues (“limitations”) mentioned in my last Post in this thread.

However, the second one “only” charges with 45W, while Purism recommends 60W (which the first one can do). However, charging with 45W did work for me as well, given an “normal” use, it just was fairly slow. So more an keeping it running then actually gaining charge.

Hi,
the OmniCharge Mobile 25600 does work for me. And I also have a Baseus 65W one, which does work too. The important thing to check is that it can deliver 20V@3A or better 20V@3.25A.

I’ve noticed that it doesn’t always start charging while off too.
But sometimes it does. I’ve noticed that changing the orientation of the USB Cable for some cables and/or power stations does the trick (don’t know why) and it also always starts charging when connected behind my USB-C PD and Display Out docking station, even when powered off and the battery is empty so it won’t boot anymore.

I’ve also had some slow charging issue. Normally when charging and turned on but idle, the laptop used around 30W. But at some point it dropped to 20W. Then also the OS won’t show an estimated time to full, but still says it’s charging (what it then does really slowly).
But this only happened behind one docking station (which was rated at 60W) and after the Laptop was under some load. So I don’t think the problem was the laptop here.

Still PD charging could be more reliable with the Librem 14 and for on the go I’ve bought a USB-C to DC jack adapter which does always work and will do the 20V negotiation. They only cost a few bucks.

Thank you for the info! I did end up buying the Anker 737 / powerCore 26k and it is working great. I appreciate the input.

Nicole, is that 65W recommended for both size battery options? The barrel jack charger that came with mine (with the larger battery that covers the second M 2 slot) is 90W. I can get USB PD chargers in 65W or 100W. I bought one in 65W based on the text above but am now thinking might that 100W model have been more appropriate for my model.

Well, this depends a bit on the usage. 65W is totally fine for average use. But if you crank everything up to 11 then it can get tight, which could mean that actually the battery drains while the charger is connected.

The problem is that if the CPU burns at full load, all cores plus GPU at full plus all USB ports used for bus powered devices and the display backlight at maximum, then the power budget can be above 65W. But when does that happen?

So for the majority of use cases 65W should be totally fine. Of course more can not hurt and can in some high power use cases be better. But do not be sorry to have bought that 65W supply, it should be fine.

Cheers
nicole

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