USB Capacity and Current Voltage Testing Monitoring the voltage/current output and power draw for devices operating on a USB port This provides a real benefit in sorting out phones, charging cables, and chargers to determine their performance quality... Screen symbol readings and their meanings: ◾ V / Voltage output from the source ◾ A / Amperage current drawn by the device from the charger ◾ T / Time since the device was connected to the charger ◾ mAh / Milliamp hours, the energy consumed by the device ◾ Reset button to clear previous data and start anew Practical and useful applications: - Testing charger efficiency and whether the charger delivers the required current - Comparing charging cables, as poor quality ones reduce charging speed - Understanding how much power a specific device consumes over a certain period