I just bought the Raspberry Pi 4 Model B 2GB RAM and I forgot my charger at my house which I won't be able to get to in a few weeks.
I was wondering if I could power the Raspberry Pi using a phone charger without damaging/frying any components.
The photo contains the power information on my charger.
2 Answers
A 3A supply is recommended, but the one you've asked about should work as long as you're not "loading down" the RPi with USB peripherals - or hanging much stuff from the +5V bus.
However, you should choose your cable with care - there are a couple of things to keep in mind:
The RPi is fairly picky about its input voltage. One of the good things about the "official" power supply is that the +5V wiring in their USB cable is a larger gage than available in any other USB-C cable that's commercially available. This is a good thing because the larger gage wiring reduces the voltage drop the RPi "sees" at its input. Lower voltage drop means your RPi won't suffer as many low voltage warnings, or potential shutdowns. The only point is this: Choose your cable carefully.
Many RPi 4 models were produced with a design flaw - essentially rendering them non-compliant with the USB-C spec. This is resolved by using a
non-e-Marked
USB-C cable. From the specs in the picture you provided, it may output either 9 VDC or 5 VDC - consequently, this may be an issue for you if your RPi is one with the design flaw.One way to check if your RPi4 is one of the (non-compliant) units:
$ cat /proc/cpuinfo | grep Revision
If the result is
Revision : b03111
, your RPi4 is afflicted with the USB-C design flaw, and you must use anon e-Marked
cable.
There are a couple of other answers here: 1 & 2 that provide more details if you're interested.

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