It says 5V/3A in technical specs, I wonder if that 3 A is a must, or is there anybody who can power RPi 4 model B via a standard 5V / 2A smart phone adapter.

Specifically, I would love to hear someone who uses a Samsung Travel Adapter(Fast Charging).

Model no: EP-TA20EBE

I'll alsoadd the picture of the adapter.

enter image description here

  • There is a lot of models for "Samsung Travel Adapter". Which one do you mean? Commented Mar 26, 2020 at 8:02
  • @M.Rostami maybe I should add a picture
    – muyustan
    Commented Mar 26, 2020 at 9:36
  • Don't add a picture when the model no is asked for, just add the text with the model no. Its impossible to search for text in pictures.
    – MatsK
    Commented Mar 26, 2020 at 12:02
  • @MatsK yep, you are right
    – muyustan
    Commented Mar 26, 2020 at 12:04

1 Answer 1


The Pi4 will run quite happily on a 1A supply, depending on what is connected. See Raspberry Pi Power Limitations

There is NO SUCH THING as a "standard 5V / 2A smart phone adapter" - all fast chargers work by using a higher voltage with each manufacturer using proprietary interface.

Most will supply 5V @ 500mA (the USB-C spec is 900mA @5V up to 20 V at 5 A), often more (although with the possibility of reduced voltage - after all they are designed to CHARGE batteries) but there is no standard, and there is no way of knowing what they will do when connected to a Pi.

  • Thanks, but I am confused, does not 5V/2A rating on the adapter mean: " at 5V, this adapter is able to deliver up to 2A of current " ?
    – muyustan
    Commented Mar 26, 2020 at 9:36
  • 2
    In an ideal world this would mean the adapter can deliver UP TO 2A at 5V. Sadly the world is far from ideal - I have tested many adapters and yet to find a single model that ACTUALLY meets its nominal spec. The Apple adapters and the official Pi supply come close, and fall within nominal tolerances. The USB charger spec allows the voltage to fall to 3.6V! Fast chargers are the wild west. All of this ignores the cable - to supply 2A @5V to the Pi the cable would need to be impractically large or ridiculously short. NOTE the official supplies deliver ~5.1V to allow for voltage drop.
    – Milliways
    Commented Mar 26, 2020 at 9:47
  • I have added an image of my adapter, of course using the official adapter would be the right choice. However, could you please tell me whether I will be able to run it via the adaper I shared or not?
    – muyustan
    Commented Mar 26, 2020 at 9:57
  • Incidentally ANY specification which doesn't specify tolerances is meaningless. No one can tell, but it will probably work if you use (and can actually find) a suitable cable. Most are too ludicrously thin to contain adequate wires.
    – Milliways
    Commented Mar 26, 2020 at 9:58
  • well, I also have the default(maybe this is not also default) type C cable came with the adapter. I don't think there will be too much load on the RPi except the camera module.
    – muyustan
    Commented Mar 26, 2020 at 10:02

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