Re: Powering Librem 14 directly from DC power outputs

I have a portable battery with varied power outputs. Some DC. Some AC.

I want to power a Librem 14 directly from the DC outputs, without converting to AC then back to DC using the power cable.

Can the Librem 14 charge thru USB ports?

If not, what power outputs would best work with LIbrem 14? And where might I get an adaptor?

Battery output options:

Car Power Output: 136W

USB-C Output: 100W

DC 5521 Output: 13.6V, 3A Max per port

AC Output: 600W

USB-A Fast Charge: 18W

USB-A Output: 12W

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is probably your simplest (and safest) option. But you would want to check what the Librem 14’s actual power requirement is to make sure that 100W covers it e.g. look at the existing AC-DC converter.

It is unclear whether you only want to “charge” the Librem 14 or actually operate it - but either way USB-C is a good option.

If you have a cigarette lighter output (is that the “Car Power Output”?) then you can get an adapter to USB-C but you would definitely need to check what power the Librem 14 requires and then get an adapter that is rated for the job. (I have such an adapter but that’s only for my Librem 5 and, simultaneously, Mrs Wade’s iPhone so the power requirement is modest.)


The Librem14 requires a DC input of at least 19V DC, so a type-C charge port regardless of Watt must be able to get up to 19V DC. I think most type-C supplies starting from 45W do 20V DC, which will work.

But please be a bit careful with type-C chargers. We had a lot of unpleasant surprises with type-C on the Librem5 and the Librem14 already. Type-C is complex and complicated and if it is not properly implemented on both sides then bad things can happen - wrong current/voltage gets negotiated, wrong timing etc.

So what I am trying to say, carefully test it, if something does not behave as expected then disconnect and do not try it again.



You can get a USB-C PD to barrel jack adapter that ought to do the trick. I use one with most of my fleet on a regular basis (but not my L14). Most systems (not speaking about Purism specifically), have a tolerance of at least +/- 10%, so even if the PD adapter feeds it 20V you’ll probably be OK. YMMV.

Why do this instead of PD directly? Based on some of the other users’ experiences, it sounds like it can be difficult to charge an L14 from flat via USB-C.

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Sure, like using the adequate quality 20V silver matte 4017 cable? Just while it is quite better that @Emily follows your kind advice precisely (if searching for a workaround that will do the job, properly do the charging job when at least equal to 65W USB-PD port used, just while and at the same time because here proposed cable will not allow negotiation of irrelevant charging protocol, like …, if so while depending on the “PD” power supply in usage, with the USB Type C cable that ensures transport of 20V/5A, as the one linked here). Another type of PD trigger/adapter (but coming from the same school) would be:

Recommending above while currently using (for many months now) from … to DC5.5×2.5 one:, and while using the recommended one in DC5.5×2.5 as well (but not currently :blush:), and can confirm it works as described (if and when related link opened).

Just in order that you understand related better, Librem 14 will not even recognize it is connected to the some power supply (at 13.6V), I might bet on this. Therefore only DC20V output from the JNS S31 IPS or from the MAXOAK K2 185Wh power banks, for example, would do the proper charging magic (with using adequate charging cable and adapter for the 4017 barrel jack).

@nicole.faerber, are you saying that the librem 14 can take 20 V, 21 V, 22 V, … DC? so the voltage specification is merely an approximate lower bound? that’s very interesting because i had (apparently wrongly) gotten the impression that computers in general were quite picky about getting an exact voltage, plus or minus perhaps 1 V. of course, i don’t even know what a volt is.

No, it is not (as tightly and modern age related to the PD2.0 and PD3.0 protocol specifications). In addition, technical facts are telling us that by itself BQ24715 supports input of 6-24V in order to charge 2S or 3S Li-ion batteries. But here it is mostly about getting/working under DC18V-20V range as (and if) PD protocol properly triggered from the used PD 20V power supply that provides reliable 3.25A (or more) at his related USB-PD 20V output port.

P.S. Also and if you open and “read” carefully above linked product page you will notice 20AWG “number” as well. Actually just referring toward designs with the DC 4.0mm×1.7mm connectors, as standard ampacity of a 20AWG copper wire is probably around 5.0A and therefore should be considered as a minimum (in order to avoid additional heat that will be produced, although it comes free of charge :blush:, yet only when and if covered by the RMA and especially if the used USB-C to USB-C cable was not the USB-IF certified one, and even if up to the 20V/3A USB-IF certified only) to be used with the Librem 14, considered even before any other type of USB-C cable intended to be connected/used as a power delivery one.

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