Monitor the condition of your battery and charging system. 

Some might consider the VM-1 to be over-built; we think it is just right. Some features of the design are:

• •White LED Backlight
• •Mil spec FR4 circuit board
• •Regulated power supply
• •Constant LED current and brightness regardless of battery voltage (won’t dim with your beat)
• •20 bright surface mount LEDs
• •Designed for 12 Volt Systems

Specifications

• •Voltage Measurement Range................................10.1 – 15.8 VDC
• •Accuracy.............................................................+/- 0.15 Volts
• •Response Time from 10.1 - 15.8 Volts...................130 milliseconds
• •Dimensions……………………………..................…2.75 X 2.75 X 0.6 Inches

Owner's Manual (PDF)