Can the usb port from a monitor power the rpi3?

bibi

Hi everyone!

Did anyone tried to power supply the raspi directly from one of the usb port available on certain monitors ? or it’s just not possible?

By the way, Is there any advantages to get a monitor with usb ports ?

Thx in advance for any feedbacks, advices, comments :)

KirAsh4

While a lot of monitors have USB ports, unfortunately they do not provide enough amps to run an rpi. All of them will be capped at either the USB1 or USB2 spec, which is 150 to 500mA. Some newer monitors have USB3 in them, but even that will be capped at the 900mA spec. An rpi needs more than that. It might run, but you’ll get erratic behaviors and random crashes from it.

bibi

@KirAsh4 hi! Thx for your reply. That’s also what I assumed but wanted to get opinions from others :) anyway thx again for taking the time to answer.
I assume therefore that there is no need for any other reasons to buy a monitor with USB ports? What’s your opinion on this ?

KirAsh4

Not for MM, I can’t think of any.

bhepler

I looked into this as well and came to much the same conclusion as @KirAsh4. USB ports on the monitors added a significant expense and couldn’t provide the power for the Pi.

If you were going to power another accessory from the monitor’s USB, it might make sense. I believe one mirror builder is running external speakers from his monitor’s USB jack. You could probably run an LED strip for accent lighting from it.

bibi

@bhepler thx also for your input on this.
I wanted to be on a safe side in case in future I would need to use/add any additional components but so far I don’t see any added value to have USB ports on the screen.
Thx a lot both for your time and help

KirAsh4

And even if you find out that you need additional devices later, you are better off with a good quality self-powered USB hub. They’re cheap, they’re small, you could even remove the whole circuitry from the case for a much smaller form factor.

bibi

@KirAsh4 I agree with your point of view - safer and cheaper. I will have a look on those hubs later… I red somewhere that not all of them are efficient with rpi3.

KirAsh4

That’s correct, and that’s because of their power outputs. You have to find out that powered and that has a nice high output. I actually run one of my rpis off of an Anker wall charger that outputs up to 2.4Amps per port.

bibi

@KirAsh4 ya a wall powered one will surely supply nice output power. If you want to share your Anker model - feel free :p

KirAsh4

Lots and lots of them on Amazon. It really depends on your application. I have both 2, 4, and 5 ports around the house for various things. Hit Amazon, and search for ‘Anker wall charger’. Then look at their outputs and do the math. For example, if you see a 4-port, 40W, the calculation is:

40W / 4 ports = 10W per port
Each port supplies 5V, so 10W / 5V = 2Amps per port.

Read the descriptions on them. I generally only buy those that can supply upwards of 2.4Amps on at least 1 port (and 2Amps on the others). But they have models that can supply that much on all ports as well.

bibi

@KirAsh4 I think it’s rather 40W / 4 ports = 10W per port :-) but no prob I got the math ;-) I will have a look and again and let you know in case. Thx so much for your time! Appreciated.

KirAsh4

Yep, mistyped … corrected it now.

bhepler

@bibi said in Can the usb port from a monitor power the rpi3?:

If you want to share your Anker model - feel free

I’m using a NextGadget 20W desk charger. Plenty of power, but I just discovered that the cord is a bit short.

If you’re looking for 2.4 Amps per port, you might want to look at Skiva.

bibi

@bhepler thx you very much for sharing! :) I will have a look