Review on Mini 3 Digital LED Voltmeter: Accurate DC 2.5-30V Red Volt Voltage Meter for Measuring Power by Muhamed Hogan

This meter works as advertised: at 2.2 VDC the digits are dim but the readings are accurate. At 4VDC it runs at full brightness and draws 30mA to power the display. The built-in current control prevents current consumption up to the limit of 30 VDC. If used to measure batteries, make sure it is turned off when not in use to avoid a slight but constant discharge. Excellent value for money and quality!