That previous thread the other day made me wish there was a cheap usb pluggable to tell you about the quality (and quantity) of voltage from a usb device.
Simple small screen or just led lights.
Maybe even a "kill-a-watt" for usb power cube/banks.
Simple small screen or just led lights.
Maybe even a "kill-a-watt" for usb power cube/banks.
- A pass-thru USB power meter. Measures volts, amps, wattage (simple arithmetic), and watt-hours
- a USB load device. You can configure the voltage and amps to draw. Used in conjunction with the above, you can see just how much a USB supply can supply
- a watch cell powered cable tester. Not essential for your use-case, but great for working out whether a cable is at fault or not.
None of this directly measures quality, but usually you can infer that from amps, and from negotiation.