Galaxy S25 (SM-S931)

Headroom Notes

Samsung publishes the port version (USB Type-C, USB 3.2 Gen 1) and never the current. 4.5 W is what the USB Type-C specification defines as Default for a single-lane USB 3.2 port: 900 mA at 5 V. Treat it as a floor, not a ceiling — the phone may advertise 1.5 A or 3 A instead, and only a measurement would tell.

Production Warning

Whether the phone powers a USB accessory at all is a setting, not a spec: USB host mode has to be enabled and some carrier builds hide it. That switch, not the wattage, is what usually stops an interface from working.