I have a power adapter that is rated at 50W (5V, 10A output), and I was wondering if it would be safe to run a single pi from it?

I am planning on using it for powering more in the future, but would it require 10 be connected (in parallel) to prevent damage?

  • How are planning to power more in the future? Using a USB hub? Commented Feb 4, 2013 at 14:16
  • by using more wires
    – topherg
    Commented Feb 4, 2013 at 14:28
  • ebay.co.uk/itm/… is what I am using
    – topherg
    Commented Feb 4, 2013 at 14:30
  • 3
    Thanks for posting the item. This is really what I would call a hard-wired power supply. Also, to answer the 2nd part of your question, you will need to connect the multiple devices in parallel to keep the output voltage at 5V. If you connected them in series ohm's law will cause the voltage to divide between the two devices depending on their resistance. You should be fine connecting more than one device as long as you ensure you never exceed the power supplies 10A output current limitation. Commented Feb 4, 2013 at 15:32
  • 2
    One risk: 10A will be able to burn much fatter wires/components than a smaller supply if something goes wrong. Good short circuit protection helps, though, but that depends on the psu.
    – XTL
    Commented Feb 13, 2013 at 14:40

2 Answers 2


50 watts is the maximum power the supply is capable of providing. RPi will take only what it requires from the power supply. As long as the voltage is 5 volts and the supply is capable of providing the current RPi requires (.700 amp) you're OK. So your power supply is OK to use with a single RPi.

  • 1
    To clarify, it will work fine as long as you are using a regulated supply. An unregulated supply will likely put out significantly more than 5V unless it's loaded to near its current rating (10A in this case). If you put a voltmeter on the supply (with nothing else connected) and power it on, and see ~5V, it's a regulated supply.
    – Doktor J
    Commented Dec 8, 2014 at 18:26

Some switching supplies need a minimum load to get good regulation. It probably won't damage the RPi, but you should confirm that the voltage is 5V without too much ripple if you can.

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