Plugable 4-Port SuperSpeed USB 3.0/2.0 Hub (With 4A Power Adapter) charging rates?


#1

Will the Plugable 4-Port SuperSpeed USB 3.0/2.0 Hub (With 4A Power Adapter) charge an ipad?

If so at what rate 900mA?

What is the maximum any one port will put out?


#2

Hi Lamar,

Thanks for posting! One thing that’s very important thing about USB charging, is the device chooses how much current to draw (based on standard signaling and software negotiation … or in the case of Apple devices, non-standard signaling).

A hub can only control at which point it triggers an “over-current” condition.

So even though our USB 3.0 hub has a 4A adapter and will deliver 900mA per port to a device that pulls it – only USB 3.0 devices will negotiate up to that amperage.

The iPad won’t. iPads will only negotiate up to higher current (than USB 2.0’s standard 500mA) via Apple’s proprietary signaling. If you’re curious, here’s a teardown of how that signaling works – it’s very interesting!

http://www.ladyada.net/make/mintyboos…

This behavior is outside of the USB specs (Apple does not support the USB “Battery Charging” spec, which is how you’d get higher amperages in a standard way … see our Battery Charging hub http://plugable.com/products/usb2-hub… for details).

It all adds up to the fact that there are no standard USB hubs that can charge an iPad at its full rate – which is unfortunately extremely confusing to consumers!

So in short, a 4A USB 3.0 hub like this is no help for the iPad - but it is useful for using with USB 2.0 devices today, and USB 3.0 devices today and in the future. And for making sure that any standard USB 2.0 device (500mA) or USB 3.0 device (900mA) can get full power.

Hope all that background helps. Again, thanks for asking ahead!
Bernie


#3

Hi Bernie,

I am looking for a Usb Hub to Connect 2 iPads and 2 iPhones and 1 iPod Classic to our Home Computer for Backup and Sync.

Also, when the Home Computer is off, I would like the hub to charge the devices connected.

Do you have any products that uses apple proprietary signaling to negotiate higher currents?

I am sure there would be a lot of people who would like to buy few of these.

With best regards,
Devang


#4

Hi Devang,

Sorry, we don’t have any products that support Apple’s proprietary charging methods. Definitely there’s huge demand for this - but the water is murky. Apple has not been supportive of a 3rd party hardware ecosystem in this area.

And unfortunately, Apple has not submitted their methods back to a standards body like usb.org, nor do they support the standard USB Battery Charging specification.

Sorry for the bad news,
Bernie


#5

Bernie,

Just received an iPad mini. Now I have an iPad 3rd gen, the iPad mini, and my iPhone5. I know that you don’t support Apple’s proprietary charging, but I think that the iPad mini and iPhone 4 can live with the approx 1A ports (they both ship with the smaller 5W adapters), and I can live with a slower charging iPad.

The question that I have is whether the 4-port actually is able to deliver 900mA to each port. When I have used other ports, they begin to blank out when the full sized iPad is plugged in because of the higher power requirement of that device.

Thanks,

Ben


#6

Hi Benjamin,

Thanks for asking! Yes, what devices are willing to pull is the limiting factor. We’ve tested the ports themselves at 900mA – both with devices and with big resistors (dummy loads) that let us test higher amperages.

Hope that helps. Thanks again!
Bernie


#7