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Not to mention it now requires a new PSU. Before you could use your standard $5 (android) phone charger at (5W), then you had to buy a 15W one and now a 27W.

To whoever thinks pi's are cheap, you can get more functionality out of a used laptop for less money, but probably worse specs and probably x86.



The standard charger is 2.5W, not 5W, and RPi3 will happily run from that, for RPi4 2.5W is somewhat marginal, but it will still work. I suspect that RPi5 is going to be somewhere around 3W (non-PD USB3).

The official RPi specs intentionally overblow the power consumption in order to provide an buffer for powering whatever ridiculous stuff people may hang off the USB ports.

Then the other issue is that all RPis need somewhat tighter voltage tolerance than what is in USB specification. So it is perfectly possible that a cable between the power supply and RPi is compliant, but has too large series resistance on power lines for RPi. And well, powering RPi from random aliexpress-grade “Android chargers” is completely another bad idea.


The old standard Pi PSUs output up to 2.5 amps (not watts), which at 5V gives you up to 12.5W.

Older boards with simpler workloads could usually manage at 1A (5W) but it was always preferred to have at least 2A (10W) to work with.


I meant “standard USB charger” from your pile of random chargers, not the one that RPi Foundation sells. Such a thing hopefully provides the 500mA, that the USB2 port is supposed to deliver.


But, you really only need the 27W supply if you need to pump a lot of power through the USB ports. It'll run just fine (even using less power) on the 15W unit with more modest loads.




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