0

I have read here that is possible to charge you pi4 with 3rd party chargers that supply 5V 3A.

I am wondering if I can use this 20W charger, which can deliver differnet voltage level (5V/3A, 9V/2A, 12V/1.5A, 9V/3A, 11V/1A), without damaging the pi4?

Can I be sure that the charger will output the correct voltage/ampere for the pi?

Update:

How does the pi4 handle the usb-c negotiation?

From the official pi schematic, the usb-c specification (I am refering to table 4-24) and this post it seems that there are two 5kΩ resistors which tell the charger that the pi4 needs 5V. Is my assumption correct?

Improve this question
5
  • You only want 5V, so there is no reason to have a variable voltage supply, only going to increase the chance that you make a mistake and fry something.
    – Chad G
    Feb 11, 2021 at 17:43
  • 1
    [pedant]You can't charge a Pi as it doesn't have a battery[/pedant]
    – Dirk
    Feb 11, 2021 at 18:19
  • I don't understand why so many are still confused about this issue. There is only one correct answer to this question, and it is, "Yes". This question has been asked and answered ad nauseum. Please inform yourselves!
    – Seamus
    Feb 11, 2021 at 19:04
  • you are using incorrect terms ... it is not a charger ... it is a power supply ... when connected to a phone, it supplies power to the battery charger which is inside the phone
    – jsotola
    Feb 12, 2021 at 5:50
  • 1
    @jsotola in fact the devices in question ARE chargers, and comply with some of the many quick charge specs, but all are required to supply 5V as default. They can, of course, not charge a Pi as there is nothing to charge.
    – Milliways
    Feb 12, 2021 at 6:32

3 Answers 3

Reset to default
1

I would recommend you buy the official Pi4 power supply.

Its reasonably priced and reliable.

https://www.raspberrypi.org/products/type-c-power-supply/

Improve this answer
5
  • That's not actually an answer to the OP's question.
    – Seamus
    Feb 11, 2021 at 18:54
  • It staggers me why people buy unknown chargers when the official Pi4 power supply is cheaper than one the OP is asking about.
    – CoderMike
    Feb 12, 2021 at 12:26
  • It staggers me that people buy "official" RPi power supplies. It's as if they believe it somehow transcends the physical world of volts and amps, and confers some sort of magical powers. I eschew buying any new wall-warts as my present collection will suffice for 4 lifetimes. All that aside, this still isn't an answer to the OP's question.
    – Seamus
    Feb 12, 2021 at 20:33
  • So you are proposing buying a more expensive 'charger' that according to your answer 'should be fine' whereas the official Pi4 will absolutely work 100%.
    – CoderMike
    Feb 12, 2021 at 22:12
  • No - I'm not proposing anything... I tried to answer the OP's question. And your claim, the official Pi4 will absolutely work 100% seems irresponsible as you have no basis for such a claim.
    – Seamus
    Feb 13, 2021 at 23:05
1

The charger you have asked about should be fine. The USB-C specifications allow the higher voltage levels, and a "signaling mechanism" that is part of the USB-C standard guarantees that as long as the device (your RPi) and the power supply both adhere to the standards, things will work as they should.

That said: The first RPi4 production units were "screwed up" - this was a design flaw that the Raspberry Pi Foundation eventually admitted. Since then, a revision/redesign has corrected the problem. It's worth noting that the original design flaw would not result in damage to either the supply or the RPi. Its only consequence was that a non-eMarked USB-C cable was required for the first production lot of RPi-4 - use of an eMarked cable resulted in no power to the RPi at all. Here's how to learn if your RPi-4 is one of the "affected" ones:

$ cat /proc/cpuinfo | grep Revision

If the result is Revision : b03111, it's an ORIGINAL RPi4 with the USB-C design flaw.

This question has come up here several times, and it has been answered several times: REF1, REF2, REF3. You will find copious amounts of detail here, but please feel free to ask anything that hasn't already been answered.

Improve this answer
1
  • 1
    cat /proc/device-tree/model && echo doesn't need any magic numbers to decode. Mine shows Raspberry Pi 4 Model B Rev 1.1
    – Milliways
    Feb 12, 2021 at 6:43
0

You mean power your Pi with a different USB C power converter. Yes it is possible to do this.With power adapters you must match the voltage output and the minimum amps the powered device will use or require. For a Pi this is the 5V/3A you have already mentioned. Any device you buy must meet this minimum requirement or you will face problems will stability of the Pi. Any other number for the voltage of the charger other than the 5V is not for your device.

If you follow that link and get to see the Canakit supply go with that. It works flawlessly with my Pi 4 and is rated 5V/3.5A a little extra for the power to be drawn from the supply. This is what the A tells you. 5V * 3.5A = 17.5W total power the 3A variety only 15W total to be had from it, the higher the A number the more power it is able to deliver without power supply overheating or shutting down.

Improve this answer
2
  • Your answer would benefit from some clarification. Your statement Any other number than one that starts with the 5V is not for your device. is unclear.
    – Seamus
    Feb 11, 2021 at 18:57
  • Indeed I have reworded, thanks for the comment.
    – user130167
    Feb 11, 2021 at 19:08

Not the answer you're looking for? Browse other questions tagged or ask your own question.