21

After searching all over my house, all I could find was an LG "Travel Adapter" with an output of 5.1V == 0.7A.

Will the extra tenth of a Volt harm the Raspberry Pi?

  • == is my best attempt at the direct current symbol. – tehtros Sep 10 '12 at 14:23
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    well there is Unicode U+2393 ⎓, but most browser's probably don't display it correctly. – orlp Sep 10 '12 at 19:45
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No. You have +5% tolerance. This means that the voltage should be between 4.75V and 5.25V. 5.1V should be fine.

Moreover, you can find such adapter on a list of verified power adapters on RPIs wiki.

Keep in mind, however, that 0.7A is quite low. It is recommended to have at least 0.7A but remember that you are on a low side of this parameter. Please also note that power adapters does not always provide what they say they are and there is some tolerance to it's values (and it's usually not specified by manufacturer). So if you have any problems with your board, I suggest you to do simple voltage test as described on this wiki page. Actually, I suggest to do this even if you don't see any problems and also test the voltage given without load on the PSU before connecting it to RPi.

  • Thank you for the link to that page! It was very helpful to me, and most likely to other people as well. – tehtros Sep 10 '12 at 14:38
  • Fast answer hey :-) – Piotr Kula Sep 10 '12 at 14:39
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    You are however, assuming that the adapter variance won't exceed the Pi's tolerance. – Rig Sep 12 '12 at 17:18
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    This is true. That's why I said "should" be fine, recommended to do the test and warned that PSUs not always provide what they say they are. But it's true I could be more specific about this, let me correct this. – Krzysztof Adamski Sep 12 '12 at 20:39
8

.1 wont hurt it but in general terms yes- stick as close to 5V as possible. The BCM chip and HDMI takes power directly from this input so going overboard will hurt it.

1A is recommended for when you are using it with loads of things plugged into it. It will fine with 0.7A but if you start to experience wierd things like resets in the middle of a encoding then you need a better power adapter.

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    Also note any USB devices take this voltage directly as well. – user606723 Sep 10 '12 at 20:03
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    Unfortunately, it's not taken directly. It goes through fuses which drops the voltage. So especially on older revisions of the board (with polyfuses on USB ports) having a little more voltage than 5V at input may be a good thing for USB devices. – Krzysztof Adamski Sep 12 '12 at 20:45
  • Also, there is a TVS diode (at least on A+, B+ and 2B models) across the 5 volt rail, so in principle, supply voltages "sufficiently" above 5 volts will cause that diode to conduct the excess voltage to ground. Exactly how much above 5 volts is required varies, but the principle is that it's not so much higher that components on the board would be damaged. – nsayer Apr 17 '15 at 14:28
  • Been powering Pi Rev 1 to Pi 2 the lateest rev with battery UBEC with input of ~5.5volts... been OK, but under load I suppose the voltage is different. ~5.25volts and has been very stable, especially WiFi – Piotr Kula Apr 17 '15 at 15:18

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