Amazingly informative thread on USB-C charging.
Thanks everyone for sharing your experiences using external battery banks. I am getting on a 9 hour flight this week. Just purchased this beastie https://www.amazon.co.uk/dp/B09FT4SHSV. My average usage seems to last 4hours or thereabouts. On flight without wifi/BT and probably much lower brightness, should last longer on its own. Let’s see.
Will report back on how good/bad/ugly it is. Was split between this unknown brand vs a 60W Anker PowerCore III. Went with the promise of PD100. 
I thought aircraft provide USB charging ??
Hmm!
Some, yes, but far from all. I’ve had more than a few seats where the port wasn’t working (even in business and first class). USB and those “universal” AC outlets take a lot of abuse, can be difficult and costly to replace, and are considered “NEF” (non-essential equipment and furnishings) at most airlines.
Bringing your own battery bank is a far safer play, especially on a flight that long.
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Reporting back, the above battery bank does seem to be able to keep the laptop in “Plugged in” mode. My battery charging is set to 80% and once it gets to 80% the amber light blinks. So I unplugged the power adapter, plugged the battery bank in and Windows continues to show “Plugged in” icon and the amber light is still blinking. Which I assume is enough proof that the bank is providing necessary wattage (?). The battery is not hot or warm for that matter.
Now to run it down and see how far it extends the laptop uptime.
My first experience with USB C chargable laptop, absolutely stoked at this 
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I have a Maxoak 185Wh battery bank which I want to use with my laptop.
So I got this. a “BiXPower USB Type C Power Converter” which is a 60W
It wouldn’t connect the orange light would flash and the usb sound would beep also I presume it couldn’t negotiate a power level.
so I got a “PWR+ car charger” which is 90W it works mostly, but sometime has the same failure mode.
I am on linux and I think this dmesg
usb 3-9: reset full-speed USB device number 2 using xhci_hcd is related.
Anyone have any thughts on what is wrong? Any logs or utils that I can run to get better insight into the problem?
Unfortunately, it’s difficult to diagnose USB-PD issues from within Linux. Everything relating to PD negotiation happens within the embedded controller and very little information is exposed to the OS. If you really want to know what’s going on, you’ll need an inline USB-C power analyzer. I’ve been using this one:
https://www.amazon.com/MakerHawk-Bluetooth-Voltage-Multimeter-Voltmeter/dp/B07P45FQW3/
That said, I have a few random suggestions that may help. The Maxoak + BiXpower combination should work in theory, as long as you make sure you’re using the 20V output from the bank. You’ll probably want to power on the bank first, then plug in the adapter to the bank, then plug the adapter in to the laptop.
It’s worth trying flipping over the USB-C cable if it’s not working. In theory USB-C is orientation-insensitive, but I’ve seen a fair number of cheap USB-C devices that don’t implement the line muxing and therefore only work in one orientation. Note that the analyzer I linked to above has this issue; when connecting power supplies with the analyzer inline, you sometimes need to flip one of the connections to get it to negotiate correctly.
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There are some debugging logs they can access to see what voltage/current is being negotiated:
cat /sys/kernel/debug/cros_ec/console_log
At least, on kernel 5.19+ (as of now, 5.19-rc6 is the latest.)
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@Kieran_Levin What if the laptop is connected to an external charger, say the original one? What protocols does each port support? Does any port support Power Delivery as a source device at 5v+?
Just basic 5V USB no matter what.
Well “basic 5V USB” can be pretty complicated nowadays… Because we have:
USB2.0 5V 500mA
USB3.1 5V 900mA
USB BC1.2 5V Up to 1.5A
USB Type-C Current@1.5A 5V 1.5A
USB Type-C Current@3.0A 5V 3A
USB Power Delivery 3.0 5V/9V/15V/20V Up to 5A
No change from normal battery power
each port will source 5V at 1.5A. One port (out of the 4) can also request up to 3A.
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@Kieran_Levin I have seen very interesting information in this thread (thanks!) but something I’m still missing is how feasible/easy it is to have a USB-C device that the laptop (e.g. acpi) really sees as a battery, not as a charger. For me, this has at least two main implications:
-
keep power saving active (and this has been mentioned before, and could be done manually, but it’s suboptimal)
-
do not try to charge the internal battery, just draw from the external battery the power to run the laptop (to avoid the inefficiency of the charge/discharge and maximize the time the laptop can run)
I believe that’s a weakness in USB-C power delivery. I hope I’m wrong but I don’t think USB PD devices need to identify if they’re a battery bank or an AC charger. So there might not be any way to do what you’d like automatically.
Read through half the thread, still my question is unanswered:
As far as I am aware, charging at lower speeds is generally more efficient, due to less conversion loss and less strain on the battery.
Since the laptop is said to take any charger, would it theoretically be sensible to put it on a slow phone charger when charging overnight? Or am I missing something here?
I tried a 15watt charger that works with Samsung phones. The Framework did charge overnight, but even that did not bring up a full charge. The unit was shutdown at the time.
I have no issues using any charger 30 watts and above.
For reference, my unit is a batch 1, 1185 I7
Was that a USB type C charger that supports USB-PD? Because 15 W should be able to fully charge the Framework’s 55 Wh battery in ~5 hours.
But if it’s not a PD charger, it would be falling back to the old USB charging spec of 5 W (or possibly 2.5 W). At 5 W, I would expect it to take ~12 hours to fully charge.
I believe it’s a PD charger, but I do not have it near me to check.
It may be an older standard for quick charging, as I believe the charger port is USB-A.
Plus my overnight is usually no more than 5-6 hours.
After the one test, I’ve always used a minimum 30 watt charger.
If a charger uses the USB type A port, it does not support PD. PD requires the extra conductors that are only present in the type C connector.
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