Power Supply information

[rurwin]

Most of the people coming to my website seem to be looking for information on "Raspberry Pi Power Supply". I have finally got around to adding an article about it.

Raspberry Pi Power Supplies

Standard disclaimers apply of course.

[Rob T]

Hi, what would your view on an Ipad charger be (5.1v - 2.1A)

I'd rather fork out for for a new charger that fits the exact requirements than fry my Pi but this one seems to fit the bill?

[cashaw]

Your iPAD power supply should be fine. It"s like your 13amp wall socket powering a table lamp (0.25 amps) . It doesn"t need all the current available, but the extra is there if needed.

I would always recommend over specifying your USB charger rather than trying to match the specs exactly. Driving a cheap USB charger at 100% of it"s rating all the time may cause it to fail quickly, or produce low voltages.

So in this case an iPAD charger would be perfect!

[kwixson]

The article says that it's important that the voltage be exactly right. How hard and fast is the rule? I have a 800mA cell phone charger sitting here that is 5.75V. Deal breaker?

[johnbeetem]

The article says that it's important that the voltage be exactly right. How hard and fast is the rule? I have a 800mA cell phone charger sitting here that is 5.75V. Deal breaker?

I don't know if there's an "official" specification on the power supply but I would not want to go higher than 5.25V, which is 5% over the ideal 5V. In practice, you may have a voltage drop of 0.1 to 0.2 volts across the micro USB cable connecting the power supply to RasPi and RasPi's power fuse F3, so a 5.4V power supply might provide a reasonable 5.2V once it gets past F3. However, this drop varies with how much current the SoC and other components are using at a given time, so it's safer to start with a power supply between 5.0V and 5.25V.

There's a good discussion of power supply considerations and problems at the RasPi hardware wiki: http://elinux.org/RPi_Hardware.

[felix123]

I'm using an iPad charger and it works fine.

[therealeasterbunny]

I'm using an HTC Desire 5v 1A charger.

Running Pi, 4GB SD card, usb to 2xPS2 connectors with PS2 mouse and PS/2 keyboard, hdmi with Debian GUI Windows. Seems happy enough so far.

[Kuma]

I just got my Blackberry Pearl Flip charge in from Amazon (5 USD with free shipping) and finally gave my Aunt her Kindle Fire charger back, both are great if you have one or the other lying around.