I currently have four raspberry pi's connected via ethernet to each other. They are currently powered by four 1A power adapters which works fine. But I was wondering if there are any devices out there that can supply enough power through usb to power the devices from a single power source. All the usb hubs I've found so far only provide a maximum of 500mA, which isn't enough.
If anyone has any links to something on amazon or ebay, that would be excellent.
Although for the moment I only need 4 high power usb ports, in the future I will be introducing more pi's to the system. So if I can add more devices per hub, then that's even better
If you don't have a problem using a soldering iron for an afternoon of nice DIY, I would suggest buying a 5v regulated power supply, like these on ebay, in combination with some wire and these connectors or similar and you can add a great amount of RPis to one supply. For example the 40A supply that is on the top of my list would have no problem at all to power 40 RPis. You'll be done for a little over 30 USD.
You are not going to find USB2.0 HUBs that officially supports more then 500mA per port, for the simple reason that 500mA is the maximum power output for a single USB 2.0 port according to the USB 2.0 specifications. In reality however many of the USB Hubs just connect the input power supply to all the output power contacts of the various USB output ports of the hub, meaning that you could dissipate the full power of the Hubs power supply over one port. But for this you need to open the Hub and see if it is constructed like that, if so you can also add a bigger power supply to the Hub itself and dissipate 1A per port without problem, BUT AGAIN: You need to check this on a PER HUB basis!
The cheapest way to do this is to get an old ATX power supply. The specs on the box should get you the max current on +5V. http://en.wikipedia.org/wiki/ATX#Power_supply
connect pin 14 to 13 to switch on.
Pins 4, 6, 21, 22, 23 give +5V.
24 pins connectors means 3 +5V more outputs as ATX 2 was intended to adress the growing demand of that voltage on post 2000 CPU/motherboards.
To power the Pis, I would recommend to solder some USB sockets, and use standard cables, rather than cuting the cable or soldering micro-USB plugs.
I have one of these, and I tested it with a Raspberry Pi B+ and it powers it up. Powers up all sorts of stuff, save for some Windows Mobile PDAs I have. They could just have bad batteries though.
There's all sorts of USB power supplies and testing gadgetry on Amazon and eBay, so you don't HAVE to make something if you don't want to.
I'm not affiliated with Sabrent, but since no one across a few different questions knew about these types of devices, I figured I'd throw in my $.02 (In case you noticed me preaching about these things).