This USB Voltage and Current Meter is a handy little gadget that allows you to keep an eye on the output voltage and current leaving your USB port when charging devices such as phones, cameras and tablets.
Easy to read display gives simultaneous voltage, power consumption over time (resettable) and current measurements.
Voltage : 4V-20V, +/- 1%
Current : 0-3A, +/- 1%
Time : 0-99H
Capacity : 0-99999mAh