The Raspberry Pi doesn’t come with its own power supply so you need to decide how to power it.
The recommendation from the Raspberry Pi website is that they have “found that purchasing a 2.5A power supply from a reputable retailer will provide you with ample power to run your Raspberry Pi”. After doing some research online it appears that most newer Raspberry Pi’s will draw about an amp at full load.
Actually its relatively easy to find a power supply for Raspberry Pi. This is because you can power the Pi by a standard 5 volt Micro USB port. These requirements are similar to most mobile phones and tablets. This means that a standard mobile charger with a USB connector should power the Pi.
If you don’t want to use a phone charger you can buy a specific Raspberry Pi power supply. There a number of these online designed for the Raspberry Pi.
Why I wont be using standard chargers
Using a single charger works well for a single Pi but running 5+ will become messy with wires. I wanted something to power my Pi which would only require one power socket and power multiple Pi’s at the same time.
One of the main requirements is that whatever I am going to use should be able to provide enough current to run multiple Raspberry Pi’s.
How to power Multiple Pi’s then?
I spent some time researching the power requirements of a Raspberry Pi. It is generally agreed on that at full load they can require about an amp of power. I finally decided on purchasing the Anker PowerPort 10 to run the cluster.
The Anker PowerPort 10 is designed as a high speed charger and is able to deliver 12 amps of power across its 10 USB ports. This has a maximum of 2.5 amps on any one USB port which is more than plenty for any one Pi.
This charger is one of the more powerful ones available and should be enough to power my cluster at full load. It was important to purchase a reputable brand as cheaper chargers can have noisy power lines. This can affect the operation of the device attached and at worst case damage them.
One of the features I like about the Anker power supply is the switch at the back. This means that to turn off the USB ports I wont need to access the power socket switch. This is important as I plan to tuck away the cabling to make the cluster have a clean interface.