Laptop discharging under high load when using a USB-C charge-thru adapter

I have a 4K display, a USB-A keyboard/mouse and the framework charger plugged into a the Apple USB-C multiport adapter (USB-C Digital AV Multiport Adapter - Apple).

(I’m running Ubuntu 21.04, with BIOS version 3.07)

I’ve noticed under heavy load (can be simulated with cpustress or video calls), the laptop starts discharging. When I disconnect the charger from the adapter and plug it in directly into another USB-C port, it stops discharging.

Additionally when when laptop has low charge, it doesn’t like to charge from the usb-c multiport adapter (the OS keeps flipping between charging / not charging).

Some reports suggest that this particular charge-thru adapter can only push out 60W. Is that the reason? Seems that framework charger only delivers 5W more, but didn’t realize it would make such a big difference.

Any idea what’s going on?

Try checking the power exchange to/from battery and see if your adapter is pushing less power into, also check if battery is reporting charging or discharging. Might be its safety mechanism of the multi-port adapter to not fuse when shorted.

Battery reports as discharging when power adapter is shown as online (even under low system load). The above script reports values between 8 - 12, when the power is plugged in via the adapter, but 0 when the power is plugged in directly.

So it does look like the adapter is faulty, as it reports power is plugged in, but the system isn’t drawing power. Is there a way to see how much power is being delivered by AC adapter?

I’ll try plugging this into other machines, as this likely looks like a faulty usb-c adapter. Thanks!

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@Tejas_Viswanath I have one as well, and for some reason it only negotiates 20V/900mA to the host even when the charger is more powerful. I have no clue why but seems to be a bug in the adapter.


There are some OEM adapters too which go beyond the USB-C spec, like for in mobile devices, oneplus5 18W dash charger only good gives 5W on VivoV20 and VivoV20 33W flash charger only gives 5W on oneplus5, idk why.

Probably there are some company specific parameter, might need to read the apple spec how handshake for >5W is completed for its charging hub.

This is because Dash Charge, Flash Charge and Warp Charge (and a few others) are not part of the Quick Charge standard implemented by Qualcomm, and thus the chargers don’t play nice with other devices.
Additionally, Quick Charge (any versions of it) have nothing to do with the USB PD protocol. But Quick Charge 4.0 supports USB PD protocols (with some additions)

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Thanks @Kieran_Levin that is helpful. I’ll get another adapter.

Curious - how does one go about measuring what is negotiated over the USB-C? Are there any software tools that can help with that, or do we need specialized pass-through devices to measure the voltage and current?

Do I understand well here…
The Framework PC laptop cant charges the battery with the official charger (just buy) when the CPU is full using is capacity ? That is it ?
Am on Manjaro, just noticing a battery issue, I was asking why :slight_smile:
(constructing Python2)

Yes, under heavy load, the laptop will consume more power than the charger can provide (at least for a few seconds).

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The gen 12s turbo up to 65W iirc (or 55W; somewhere along the lines)
Throwing in fans, display and other parasitic loss and you would be below the brick output of 60W.
But you should be able to mostly “get-even” with the power draw.
It might also be because of a “cheap” dock that might not be capable of delivering all the 65W power to the laptop (e.g., instead it can only deliver 45W)
In which case isn’t really the framework brick’s problem.
You can try plugging in the laptop directly to see if it helps. If anything it will waste less power in the hub.

Am not sure to understand how to do in pratique.
I can buy a bigger charger from FW.

For gaming, I have no problem under a Windows 10 partition.
Same game on Manjaro Steam need to stop my game (do a pause, recharging)

It’s OK but it is a limitation.
A full charging could help the acceptance of FW pc on the market :slight_smile:

I will searching an alternative charger :

To fix my surcharge use…

  • I change my BIOS settings == I put CPU in : “Non Turbo-Mod”
  • I also try “Slimbook” Application

( now am fine playing my game )

You likely need sniffers (with the built-in negotiation chips and code). Alternatively, you can dismantle a USB charging cable and probe the VBus (positive and negative) pins. This can give you an idea of the voltage they agreed on.

From the design Apple approached its most likely that it’s a limit within the “Multiport AV Adapter”. Its a slim design so it wont have a large capacity to carry through lots of power.

Or Apple’s software lock, but given the protocol its not likely to be the No 1 factor.

The FW13’s PSU has capped. I tried 60W, 65W and 100W power bricks, all give 20V 2.7A when the battery is not full regardless of what you are doing. When idling the battery charges at ~44W and when gaming it charges at ~4W, i.e. no constant current charging, the charge rate is capped by the power rating of the internal PSU if the power brick is at or above 60W, until the battery reaches constant voltage charging.