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I have a model B raspberry pi and an external hard drive that requires more power than the usb port on the raspberry pi can provide. Is there any way to increase the power to the usb port so that I can connect the hard drive to the raspberry pi without using a powered usb hub?

  • You seem to have answered your own question! Why do you not want to use a powered USB hub? – dmeehan Aug 8 '14 at 14:56
  • I do not want to use a powered usb hub as I don't have one and would prefer a workaround rather than buying a hub. – Mowing Bar Aug 8 '14 at 14:58
  • The work around is to buy a Y-cable then, like this: amazon.com/Waltzmart-Splitter-Power-Cable-Drive/dp/B009O4ZW56/… – Tyson Aug 8 '14 at 15:12
  • Do not attempt to add more power directly to the board. A solution I use is to have a monitor with an internally powered usb hub. I plug the usb power of the pi into the screen's hub, then the Pi usb to the usb data port on the screen. This way i get 3 powered usb ports, and turning on my screen turns on the Pi. It also means Ive got only one power cable. – j0h Aug 8 '14 at 19:46
  • Get a Pi B+. This can supply 600/1200mA. – Milliways Aug 8 '14 at 23:55
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If you are willing to modify an existing USB cable, you can remove the +5V line from the Pi and add your own +5V power supply to the line. Research the pinouts before you get started. A good discussion of doing something like this is on Head-Fi.

There are a few important notes though that need to be highlighted before trying this:

  • Your external power supply, the Raspberry Pi, and the USB device must share a common ground. If using standalone power supplies, they should be on the same circuit.
  • USB devices expect +5V +/-0.2V. If you are on batteries, what is your expected behavior when the batteries are dying. If you bring your own power supply, have you tested it for conformance both without and with a load?
  • The USB device may not tolerate line noise, so be aware of your power supply type and what kind of filtering comes with it. An existing USB power supply, like those needed for the Pi, are probably your best bet.
  • Do not let your external power supply connect to the host +5V pin since the behavior on the Pi probably involves letting the smoke out of the wires.
  • I would think twice before using a Y-splitter in combination with an external power supply, since you will be violating the line on the previous bullet.
  • I had decided to create my own Y splitter usb cable to power a portable drive and connect it to Pi. I then first switched on the power to the drive and then powered the Pi. What happened was that the Pi would power on even when I would power just the drive. The mistake that I had done was I did not cut the red power line going to the pi in my home made Y cable(as mentioned in zerolagtimes first line in his answer). I did not know that the Pi can take power – ad77 Mar 2 '15 at 10:08

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