The Dyna voltage monitor is necessity for any 12 volt battery ignition vehicle that does not have a charging system such as many race vehicles. The voltage monitor gives a clear indication of battery condition at any time with a quick glance at the three indicator LED's, green, amber and red. When the green LED is on, the battery is on, the battery is charged. When the amber LED is on, the battery is starting to get low. When the red LED is on, the battery is low and should be recharged before future use.