Voltmeter Gauge Wiring Diagram A continuous reading of less than 13 volts indicates that the charging system is not working properly and will eventually result in a discharge battery. High sensitivity and easy operation, professional installation is highly recommended. If the meter is higher than 15 volts, this indicates that the voltage regulator of the charging system is not working properly and that it can lead to damage to the battery and accessories. Auto Battery Voltage Monitor 12V Voltmeter Gauge 2 52mm Volt Voltage Meter Gauge Universal Pointer Voltmeter Car Auto Measure Range 8 16v Led Light Dial Blac Dashboard Volt Gauge With Led Unit: Volt. LED light on the dial for easy reading in the darkness Dial material stainless steel, strong and durable. Specifications: Diameter: 2 inches 52mm Measuring Range: 8-16V Product size: 70 * 70 * 60MM Gross Product Weight: 135g Product net weight: 95g Voltmeter color: black Dial material: stainless steel Product Features: Measure the voltage of the power supply of the car Package Contents: 1 x Voltage Meter 1 x Bolt Pack 1 x Instruction Important Note: The voltmeter meter indicates the electic pressure or voltage, It provides easy to understand information about the condition and operation of your vehicle's electrical system. 12V Universal 2 (52 Mm) Car Voltmeter With 7-Color Led Display And Tinted Front Panel Buy cheaply on Package Including: 1 x Tension Gauge, 1 x Bolt Package, 1 x Instruction