A Pi5 does not "measure" the (current) capability of a connected power supply. The power supply has to be PD compliant and respond to the Pi5's negotiation appropriately which, of course, your supply & cable cannot do and so the "lowest capability" is presumed (but can be overridden). How long is the cable? Have you checked the actual voltage drop under load? (Transient droops can only be detected via an oscilloscope not a multimeter)Hi,
I’m using an RP5. It is connected via a super big home made cable to a 10A power supply.
When I start it says the power supply is inadequate and it will restrict USB power. I have stuck a voltmeter to measure the output of the power supply and it never stops below 5.1 during boot, or indeed ever.
Before I start again with making a cable: maybe my soldering wasn’t good enough etc. I thought I’d check how does it know the power supply is inadequate?
The power supply and wire are both overkill and I thought my soldering was okay. It was only adding a 4 pad USB male connector to a wire, so not exactly complicated. I put shrink plastic on that end so I can’t measure the voltage there. Maybe there is a resistor on the USB-C which tells it the amperage is limited?
Trev.
Statistics: Posted by FTrevorGowen — Tue Feb 06, 2024 11:31 am