Total power output from all USB C ports

I am considering building a 3 display portable computer based on those cheap 15 inch USB C portable monitors in a portrait orientation and framework mainboard and battery all wrapped up in a 3d printed folding housing. I know the mainboard and battery could easily drive one display and considering the mainboard isn’t driving the built in monitor I’m pretty sure it could do two no sweat. but I’m curious if anyone has an idea as to how much power can be pulled from the mainboard simultaneously. I will be supplying 96 watts with a rather beefy PD bank, and draining the mainboard attached battery isn’t much of an issue because I only need the unit to last 3 hours off a charge. I would like to keep this as relatively simple as I can and avoid the use of USB C hubs because if it works, I’ll be using it pretty heavily.

In summary, how much power can I pull from/push through a framework mainboard without killing it?

As a reward for anyone who made it through that wall of text here is a picture of my Framework mainboard Daily Driver. Triple 4K monitors connected to an i5 11th gen acting as an email/spreadsheet surfer and as a thin client for my more powerful machine.

That’s easy. Each port can deliver up to 100W (20V@5A). No monitor should be pulling anywhere near that kind of wattage, especially if designed to be portable. I’m guessing around 10-15W max per monitor? Given the amazon answer from the manufacturer for this portable monitor it seems 10W is a reasonable guess. I would not go higher res or higher refresh rate as that will increase power draw.

That has some schematics if you want to know more technical stuff.

It looks like you wont be able to daisy chain monitors together unless they support PD passthrough and video on the same cable and that seems unlikely and would definitely drive up the cost of the monitor so You’ll need to use all ports to make this a reality but it is :100: achievable. Your best bet is to find a portable monitor with an integrated USB hub to avoid any docks.

Ports can supply a max of 5v at 3amps on two ports and 1.5 amps on the other two. Input doesn’t matter as long as it’s PD.


I can accept being wrong but why is power delivery different than power inputs?

The circuitry for supplying the higher voltages required by PD for the >15W range of outputs probably isn’t present on the mainboard as its not something most people expect a laptop to do. Usually the only devices that have bidirectional USB PD are power banks.

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What voltages, currents, and wattage is the Laptop capable of supplying to a connected device? Also, is it restricted in anyway (ie. do I need to change a setting to let it provide more)?

I am trying to power a device that requires 9V-20V from a USB-C cable, but it consistently claims an under-voltage condition. I suspect it is getting 5V and is unable to negotiate for more, but I don’t have a good way to confirm that is the case. It can peak out at 65W, but I am not planning to use it for extended periods of time, a couple minutes at a time is my use case so I’m not worried about killing the laptop battery.

I think recall it being limited to 5V, but I don’t have a source I can link.

I don’t believe this is wise honestly. 9V is ok but outside of what most USB is designed to output. The bigger question is at what amperage are these voltages going to be used? At 65W with 9v that is 7 amps!! 20V is around what the Framework laptop prefers to charge at, through a specific charging BMS. Desktop computers do not output 20V and they have power supplies plugged into the wall.

When you factor that your Framework could require that exact same voltage for operation, then you would have a race condition, and a battery not designed to supply that kind of output.

I’m not an expert, but I’m advising you to look to powering your device externally.

The device scales its power output, 65W only occurs at 20V! Otherwise, I agree that would become a hot cable pretty quickly.

That being said I have been running it off of an appropriately sized USB charger without issue, but had been hoping to power it on the go when I don’t have access to the grid. That doesn’t happen often so I might just invest in a portable battery that can handle it.

Thanks for your responses!

Welcome to the forum, but please read more :slight_smile: for example
Asked your query be moved here

But with a 55W battery and a max of 3A x 4 what do you want?

My apologies, I searched for quite awhile before posting. The keywords I was using kept bringing me back to discussions of how to charge the laptop and inevitably to a post asking if you can charge the laptop with 4x 15W chargers :roll_eyes:

3A @ 5V is plenty for most devices intended to be used with a laptop. My use case is definitely atypical and would have been a nice to have feature. Thanks for pointing me to this thread.