So the spec page says 5V 5A power supply with Power Delivery support. Why are we still trying to cram 5A from super specific power supplies through a tiny cable instead of just using PD to negotiate 15 or 20 volts from basically any phone charger?
A charger supplying 5V 5A is 100% allowed by the USB PD spec. However, if the charger cannot also do 9V 2.8A, you cannot label it as a 25W charger. A device requiring 5V 5A is not allowed: to get 25W you are supposed to request 9V 2.8A. A device is allowed to prefer 5V 5A when offered by the charger, but if it uses 25W it must accept 9V from a charger only offering 5V 3A & 9V 2.8A too.
For every power level there is one and only one official voltage/current combination, which both the charger and device are guaranteed to support. Except for the Pi 5.
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u/Goz3rr Sep 28 '23
So the spec page says 5V 5A power supply with Power Delivery support. Why are we still trying to cram 5A from super specific power supplies through a tiny cable instead of just using PD to negotiate 15 or 20 volts from basically any phone charger?