General charger through USB-C

The European Parliament voted today for a law demanding that from year end of 2024 all devices must have and use a standard USB-C port for charging so that mobile buyers don’t have to buy a new charger with the new mobile (to save resources and money). So far so good the idea.

Thinking in our L5 which is unwilling to charge from any other “normal” 5V source, what this would mean?

How do you come with this statement?
Many of us use the Librem 5 through a docking station which means that we are charging the Librem 5 through a different source then the shipped charger.
Since I learned that 5V 2A are also sufficient, I know often use a Samsung 5V 2A charger instead of the Purism 5V 3A charger.


I am skeptical as USB-C is just the form factor with so many different implementation behind, that there is a huge potential for a pure chaos.

Just thinking of Raspberry Pi 4 as an example which initially shipped boards that were almost impossible to power without the Raspberry Pi charger. And even after the revision in later versions it is still risky to use them without the Raspberry Pi charger (which is btw marked as 5,1V and not 5V).
Before getting the Librem 5 I was also totally unaware about how different one USB-C can be from another USB-C and how complicated the topic is. I wonder if the people who voted today in the EU Parliament realize the huge implications.

Another example - I have a power bank that has both USB-A and USB-C output slots.
When I power Librem 5 with a USB-A to USB-C it gets more power than if I power it with a USB-C to USB-C from the same power bank. The USB-C to USB-C should on paper be able to deliver more power, but in reality the USB-A to USB-C delivers in this case more as apparently the USB-C to USB-C negotiates lower A.
The topic is really huge.


In 2013 I have ordered and built this Minty Boost kit:
It charged nicely my Openmoko Freerunner and later in 2015 my Ubuntu mobile BQ E4.5. It delivers “nearly” 5V @ 500mA. You can’t use this with the L5.

I wouldn’t call that a “normal” power source though. But then again, the L5’s 5V 2-3A isn’t really “normal” either. But hey, at least it’ll stop Apple from insisting on their lightning connectors.

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Yes. I think the execution will be poorer than the idea. In other words, while the idea is reasonable and the motivation is fine, in practice it will not work as well as people hope.

For example, it could have the perverse “unintended consequence” that people throw away all their existing USB-C power equipment and buy new equipment because the existing equipment doesn’t work well enough in practice with their new device that came without power equipment.

SNAFU. They never do …

I can see a situation where you have to carry around a USB-C power meter to debug this sort of thing. Or maybe USB-C chargers will come with that built in.

Allegedly, USB-A powering the Librem 5 is limited to 500 mA, which is sort of enough to run the device but probably not to charge the battery.

I assume that USB-C PD negotiation is “failing”. Possibly the power bank does not support the right power protocol and version. Do you have documentation for it?

cat /sys/class/power_supply/tps6598x-source-psy-0-003f/uevent

is your friend.

Or maybe Apple will keep the lightning connector and provide a USB-C to lightning adapter i.e. a small passive adapter that is enough to do charging but maybe not enough to do data.

The EU may have been at least as concerned about wireless charging as they were about lightning.

Although you are talking about PD protocol … here are my two cents. IMO (concern), it is about having APPLE 2.4A protocol negotiated (up to 5.2V range) to charge Librem 5, as sink (over USB-C output source as well), and therefore produce extensive heat (in short). It is about mostly having Apple 2.4A protocol present (if not avoided) within USB-A or within USB-C power supply controller. It is about that the same power bank with few charging outputs having ports with and without APPLE 2.4 present:

Badly selected charging port (if so):

As pictured above (perhaps needs to be further researched), but SAMSUNG 2.0A protocol is not disturbing factor (interfering protocol) as when charging Librem 5 with such power supply Librem 5 will pick up USB-DCP (5V/1.5A) protocol (might upload some evidence if needed).

P.S. Now someone might understand on why here related manufacturer lough, not so much as before, while transparent presence is gone now (to them it is that Apple 2.4A protocol being sold all over) over this particular decision (supporting/being present within so called general full protocol power devices).

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If I understand what you saying, yes, the EU might have to come back after a few years of customers tearing their hair out with combinations of device and charger that don’t work or don’t work well and standardise which actual charging protocol is offered.

For sure, when it doesn’t work, you can get finger pointing. Device manufacturer blames charger manufacturer and vice versa. That is a problem that did not previously exist.

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According to OP:

so not an adapter, but maybe an additional charging port, although I have my doubts about that.

The devil would be in the details.

If the goal is to allow mobile phones (and other affected devices) to be sold without a charger - if the goal is to allow two disparate phones to use the same one USB-C charger (not necessarily at the same time) - then there is nothing wrong with using an adapter.

What does the legislation actually say? I don’t know and I’m guessing that neither you nor the OP know either. :wink:

An adapter is a fairly sensible approach given that there are a zillion legacy devices that won’t have a USB-C port anyway. That way you can use a new charger with a legacy device (assuming that the legacy device outlives its existing charger). (In the Wade household it seems that it is the cable - lightning to USB-A - that dies first. We’ve had to replace several.)

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Quarnero, The gadget you show in the pictures, what is this exactly for a model and from where could I get it? It seems to not have an USB-C interface, or I’m wrong?

You mean the USB power meter? I bought mine from Amazon. It has USB-A going across and USB-C going at right angles (hence does both).

I have different experience. Having USB-A to USB-C in the path leads in my experience to better results and both negotiations and measurements above 0,5 A.

My interpretation is that when having USB-C to USB-C you might come to problems in the negotiations and end up with 5V 0,5A, while with USB-A in the path it falls back most likely to BC 1.2 which is up to 5V 2A for our case.


Fair enough. I was relying on e.g. Librem 5 USA - Read Before Ordering but it does depend on exactly what “non-PD sources” means or for that matter what protocols the USB-A port at the supply end is capable of.

All the more reason to need diagnostic tools for when the power protocol doesn’t work.

I come back to: Or maybe USB-C chargers will come with [a USB power meter] built in.

I guess that this info from August 2021 is outdated in the meantime.

Actually it does have two (entrance and output) USB-C ports:

Anyway, @guru, please check those two links: and (and let me know which one might suit your needs, A2 shown here, and relatively cheap, you can send PM to me, in German please, explaining your preference). Gadget shown in my previous post is old one and I’m not recommending it for purchase as of 2022. Also AVHzY CT-3 might easily be the best USB meter (but I do not need additional one).

And, IMHO, all actually comes down to getting equal readings from D+ and D- (from USB tester): 0.04 and 0.04 when Librem 5 battery at 100%, coming down from 0.07/0.07 (or so, I’m tired now) when USB-DCP protocol negotiated for both D+/D- outputs in parallel. Actually I cannot explain this, not even coarse, not yet.

I own such a small gadget as well. When I connect it to the L5 power supply with two original USB-C cables it charges the L5 see photo (though, the gadget does not say anything about the used protocol). See first photo:

If I connect the gadget to the power supply with some USB-C / USB-A changer, it does not charge, see 2nd photo. Why it does not work that way?

I think because it has to go either across (USB-A to USB-A) or down (USB-C to USB-C).

So if you want to use the supplied charger with an adapter to USB-A, you will then also need to use a USB-A to USB-C cable to connect the USB meter to the phone.

I believe there’s a manual available for that device but it is probably in Chinglish which would be even more challenging for a person of non-English speaking background. :slight_smile:


Oh, yes. And it is working that way:

There is a relatively good manual in PDF in:


Thanks for related manual! As written there this USB tester is able to: Fast charge recognition mode: QC2.0, QC3.0 and therefore would show/differentiate only two stated protocols or show (see page 6 and note that you can read D+ and D− which would be for both channels at around or less then 0.04 for both, when USB-DCP protocol actually used, after red LED light turns off):

As second, please note that your posted picture shows that you downgraded current flow three times: once is OK (will increase charging time somewhat but protect Librem 5 from getting hot (and, let us guess, somewhat increase its battery life). Having two cable pull-up 56k resistors is already too much but should charge Librem 5 battery anyway (with having its screen off). Just avoid USB-A channel of this gadget (see below), especially if not directly connected to USB-A power supply output (those USB-A ports, power supply ports, are more then often QC protocol series related, in orange color, rather not the very special blue reserved for BC1.2 protocol, yet sometimes hiding the one to be avoided: Apple 2.4, while not having good taste with Librem 5, at least not to what I expect to get out from used power supply when Qualcomm/Apple protocols not needed). Also please do not use USB-C to USB-A adapters for charging purpose in general (like Anker OTG adapter shown), while those usually cannot transport more than 5V/1A, and might burn out easily (I guess, but certainly relies on particular adapter features).

Also, please start to move around those four multi-function buttons just by having only connection between original Librem 5 power supply and USB-C input to learn more about those switches (gadget screens options, seven independent screens, I guess).

Now, just to add to what @irvinewade correctly noticed, I’m quite sure that your USB gadget is not of bidirectional type and therefore can be used just in direction of arrows printed there and (as already written here today) actually two one way channels (USB-A input->output and the other channel) bridging each other (but not crossing).

Micro USB port there is probably not supporting charging function either (while no micro USB output there, confirming again what already kindly noted).