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I read that the current should be at least 700mA. can I use HTC Google Nexus One charger as my Raspberry Pi power source supply ?

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Does the charger supply over 700mA? –  XTL Aug 14 '12 at 7:55
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Yes- The HTC chargers are the recommended power supplies! Only cheap knock off's run at 500mah (like from eBay) Original HTC chargers all supply 1000mah. –  ppumkin Aug 14 '12 at 10:00
    
Yes, you can! :) –  Marius Butuc Jan 23 '13 at 2:55

3 Answers 3

up vote 12 down vote accepted

First of all, you should check the label on your charger. You should find how much current it can provide. It's the only proper way to check this. Even if somebody here has HTC Google Nexus One, he may have different charger. You should not assume that the product will always have identical accessories (even thou it's very often true).

Please keep in mind, as I mentioned couple times in different answers already, that charger rating is not the only important parameter. It's very important what voltage will you get from your supply under load. It's easy to test if you have a multimeter. You should check voltage between TP1 and TP2 points on your RPi after you turned it on (it should be between 4.75V and 5.25V).

There is one another parameter - it's voltage ripple. This one is hard to test as multimeter will always show average voltage. You would need to have oscilloscope to test this. Also note that although the RPi only requires around 500mA to run, connecting USB devices, especially WiFi dongles and other high-powered devices will require a power source with higher current than 700mA

So the truth is - you have to test this yourself. If your label says it's at least 700mA, it should be working. You should connect it and test if your RPi is working stable. If you are getting random hangs or repeated keyboard characters or any USB device seems to be disconnecting/reconnecting itself, it may be that your power supply is not good enough. Please note that it should not be dangerous to use power supply as long as it provides 5V and all microusb ones should. Worst that could happen is corrupting the filesystem (not really likely) on your SD card after RPi hangs or reboots itself. Re-flashing the card will fix this.

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I'm not convinced about aspects of this answer. Each USB port is limited to 140mA, so that's 280mA in total. Plus the 400mA used by the SoC, I would like to see evidence that you can pull more than 700mA from a charger. –  Alex Chamberlain Aug 14 '12 at 10:32
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Keep in mind that there are couple other things that could take power other than USB ports and SoC. There's LAN chip that IIRC can take up to 230mA, there's HDMI, GPIOs etc. And the problem is not about how much current can RPi take but about the voltage that the power adapter can provide at at that load. Most adapters I have seen drops a lot of voltage when they are providing current close to it's max. And it's always good to have some safe margin for power consumption peaks. –  Krzysztof Adamski Aug 14 '12 at 10:53

Umm.. Have you looked on the charger? Most chargers will have a little printed information box on them: you want to look for something that says:

Output: 5V 1A

or similar. If it shows over 700mA (or 0.7 A) then it will be good.

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Can't it be too high? I'm a little bit noob-ish about electronics so sorry about this simple question. –  Wietse de Vries Aug 19 '12 at 19:31
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@WietsedeVries Nope, the Pi will only draw the current it requires. (ie you could use a 100A power supply, and it would work just as well as a 1A one) –  bearbin Aug 19 '12 at 20:08
    
Off-topic: Applies that for every electronic device? –  Wietse de Vries Aug 19 '12 at 20:40
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@WietsedeVries I am quite sure yes, but not for voltage! –  bearbin Aug 20 '12 at 7:01

Yes you can I use it without problem it is 5V 1000mA

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