0 Ohm Resistor 3-Cell Battery Mod for Librem 14

[FranklyFlawless]

There were no technical issues, and no other significant hardware components were upgraded during that time.

Librem 14 charging and battery problem

It was for an upgrade. When I ordered my Librem 14, there was only the 4-cell battery at the time, which only allows for one included NVMe drive. I wanted to use two NMVe drives instead, so I told Purism to not include the 4-cell battery so I could use the space for both NVMe drives. Later on, when the 3-cell battery became available, I shipped the Librem 14 back to them to install it and the second bracket for the other NVMe drive, so it can be properly secured on both ends instead of just th…

[carlosgonz]

@FranklyFlawless

and no other significant hardware components were upgraded during that time.

so that mean that your machine it is L14s looks like.

[FranklyFlawless]

Indeed, the genuine article.

Purism Librem 14 v1

[carlosgonz]

@FranklyFlawless

Indeed, the genuine article.

Ok it is L14

[carlosgonz]

@FranklyFlawless looks like Nova NV41 it is TOP Machine for Qubes on their certified. However i could never buy it this NV41 Clevo-OpenSource-Propietary-Computer.
I get very Nervous about OpenSource things, for sure as Open Source it is not Libre Software.

[carlosgonz]

@walidmujahid how is going?

I changed to 3 cell battery on my L14 just now and evethithing work good, without changes any resistor.

[jonathon.hall]

@walidmujahid I checked in with support to get the answer here for you.

For future readers, this is not needed on all Librem 14s, only specific board revisions. If you are switching your Librem 14 from a 4-cell battery to 3-cell, you can compare it with the photos below.

Devices that need the 0-ohm resistor look like the middle image. Between the battery connector (left) and the M.2 Wi-Fi socket (right), there is a single transistor marked Q37, and there’s no 0-ohm resistor across the left side leads. You need to install the 0-ohm there and solder it to the two leads on that side. (Orientation does not matter.)

The left image is a more recent revision, Q37 is not populated, instead R76 is placed across two pads. This device doesn’t need the change. (Note that there is another transistor in a similar location marked Q26 in this revision, don’t confuse it for Q37.)

The right image is a device with the 0-ohm resistor installed. Either battery can be used, this change has no effect on the 4-cell battery.

[carlosgonz]

@jonathon.hall as you can see on @FranklyFlawless picture that Q37 looks different or place than ur 3 photo examples…
Also the Resistor that do not support 3 cell what ohm it is?

[jonathon.hall]

Yes, that’s another board revision. That one does not have Q37 at all and doesn’t need any change.

You’re right, I probably should’ve included that one too, guess I was focused on identifying Q37 (and the fact that the revision on the left has an easily-confused Q26).

@carlosgonz

Also the Resistor that do not support 3 cell what ohm it is?

This change isn’t replacing a resistor, it’s adding a 0-ohm resistor across those two leads of Q37.

[carlosgonz]

@jonathon.hall
What is the Function of the Button that appears marked in Red below in the Photo?

Thanks.

photo from FranklyFlawless above.

[jonathon.hall]

It’s a power button, it’s identical to the power button on the keyboard.

[carlosgonz]

@jonathon.hall

It’s a power button, it’s identical to the power button on the keyboard.

Great.
Thanks for all the responses, i appreciate it.

[walidmujahid]

Thank you all for your help. Sorry for not replying sooner. Tommorow I am going get my brother to help who has access to a fine tipped tool solder. I’ll update you guys as to the success.

[walidmujahid]

Alright. Thank you everyone for your discussion and help. The resistor is installed and the battery is finally charging. It’s at 8% now and has 16:48 left to go. I marked @jonathon.hall answer as the solution.

[carlosgonz]

@jonathon.hall

It’s a power button, it’s identical to the power button on the keyboard.

It is possible to use that power button with a new Purism M2 E UART Module to debug BIOS?

Thanks

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Dear @FranklyFlawless can you share a photo of the bottom of your Librem 14? i pretty sure that ur Librem 14 it is v2.

Thanks

[FranklyFlawless]

It is version 1 and from the earliest batch, as it does not have a CMOS battery.

Workarounds for running Librem with dead battery?

The first run or two did not have the extra battery, so you were probably correct in that you didn’t see one when you had it open. Mine at least didn’t and I had one of the first L14’s.

[carlosgonz]

@FranklyFlawless

It is version 1 and from the earliest batch, as it does not have a CMOS battery.

Really? is very interesting for some reason…
As far i know there are Librem 14 v2 out already.

Thanks

[jonathon.hall]

@carlosgonz

It is possible to use that power button with a new Purism M2 E UART Module to debug BIOS?

Should be, you’d need to enable the UART console in coreboot, configure it for UART 2, make sure the GPIO pad muxing is correct (maybe do it in bootblock if you want bootblock tracing), etc.

BTW the EC ignores power button presses (either button) if the lid is closed and AC is unplugged, as resiliency to make sure it doesn’t spuriously wake up in a bag, etc. So you have to either plug in AC or open the lid a bit for it to respond to this power button.

[jonathon.hall]

@carlosgonz

Really? is very interesting for some reason…
As far i know there are Librem 14 v2 out already.

The RTC well (powers the CMOS RAM and clock) is also powered by the system battery, which means the CMOS battery is mainly for redundancy if the system battery is so discharged that it can’t power the RTC well.

We did start adding them though as loss of the RTC clock is more impactful to systems using PureBoot with a Librem Key than to the average computer that can just sync it again after boot. (The RTC clock relates to GPG key validity and TOTP if you use it as a backup for HOTP, all of which happens when there is no network connectivity.)

edit: And there’s no Librem 14 v2 yet, the minor revision made recently is called v1-02. Some components changed like the audio codec and CPU stepping, but there’s not really any functional difference so it’s still v1.

[FranklyFlawless]

@jonathon.hall

And there’s no Librem 14 v2 yet, the minor revision made recently is called v1-02. Some components changed like the audio codec and CPU stepping, but there’s not really any functional difference so it’s still v1.

The minimum Coreboot and PureBoot version supported also changed to 4.21-Purism-3 and Release 28.2, respectively, although I do not recall any threads needing to specifically downgrade firmware for either Librem 14 revisions, only the Librem Mini v2.