KWS-10VA Keweisi Voltage/Current USB Detector. , a compact tester used to measure real-time voltage and current of USB-powered devices. Key Features and Specifications Dual Display: It features a dual-digit LED display that shows Voltage (V) in blue and Current (A) in red simultaneously. Measurement Range: Voltage: Typically measures between 3V and 9V (some models support up to 20V). Current: Measures between 0A and 3A (with a maximum tolerance up to 5A). Plug-and-Play: The device does not require an external power source; it is powered directly by the USB port it is testing. Connectivity: It includes a standard USB male input and two USB female outputs ("OUT"), allowing you to test two devices or cables at once. Common Uses Charger Testing: Check if a wall or car charger is providing the advertised voltage and current. Cable Quality Check: Identify faulty or low-quality USB cables that may be slowing down charging speeds. Device Power Consumption: Monitor exactly how much current a smartphone, tablet.