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powering RPi via computer's usb port?

Posted: Thu Aug 09, 2012 2:22 pm
by jehan60188
I know i've read that my computer's usb port shouldn't be used to power the Rpi, because it can't supply sufficient current, but it seems that for usb 3.0 the "USB-IF has upped the maximum bus power output from about 500 mA to 900 mA" http://www.techspot.com/guides/235-ever ... ut-usb-30/

so it seems usb 3.0 will be able to provide more than enough power?

Re: powering RPi via computer's usb port?

Posted: Thu Aug 09, 2012 2:28 pm
by bredman
Some people have reported success, but there are no guarantees.

Re: powering RPi via computer's usb port?

Posted: Thu Aug 09, 2012 2:37 pm
by RaTTuS
when I powered it from my computer usb ports it worked fine ... I've now moved it elsewhere

Re: powering RPi via computer's usb port?

Posted: Thu Aug 09, 2012 2:40 pm
by JoeDaStudd
It depends on what your planning on running on the Raspberry Pi and any extras like usb dongles, wifi adapters, etc .
I've heard of good quality 750mamp mains adapters failing to supply enough to run a wifi adapter and the RasPi at full load.
Then again for headless with no usb devices I can't see why it wouldn't work.

To to fair the best solution in terms of powering the RasPi via a desktop computer would probably using a pc psu which has a usb connection on the back for charging mobile phones as it will be rated (ampage wise) much higher then any standard usb port.

Re: powering RPi via computer's usb port?

Posted: Thu Aug 09, 2012 3:10 pm
by yttriuszzerbus
This is definitely possible, but your USB port might not be able to supply enough power for many peripherals. Also, if your PC switches off (think Windows Update), it'll take your RasPi with it. Putting "usb wall charger" into Amazon.co.uk, I see some that cost only £3-4, and it's definitely worth the small investment.

Re: powering RPi via computer's usb port?

Posted: Thu Aug 09, 2012 3:16 pm
by Jim JKla
Mine worked fine but I have since moved to a Belkin 7 Port Powered 6v 4a Hub F5U010.

Spec only supplied because every time I mentioned it I've been asked the spec ;)