Features: 2" ROUND Battery Indicator Meter Gauge 12/24V 36V 48V 72V for Boat Golf Cart Yamaha Club Cart Forklift... The battery meter has 10 LEDS that will light to show the battery condition. When fully charged, only the 10th LED will light shown a green LED. Auto Ranging Battery Monitor - Connect to any fully charged lead acid battery system and the meter will select the proper range, for 12V, 24V, 36V,48V or 72V DC systems. At approximately 30% battery life, the #3 LED will light and the color is Yellow as a caution indicator; At approximately 20% battery life remaining, the #2 LED will light as a Flashing Yellow; When the battery discharges to approximately ~10% remaining life, the #1 LED will start FLASHING RED with the #2 LED FLASHING Yellow alternately.