Searon Mini 12V 24V LED Battery Indicator Gauge Meter for Motorcycle Golf Carts Car Marine ATV LED Battery Meter Indicator Meter Works on 12 volt / 24 volt Lead-acid batteries. 5 segment LED bar graph display with 10% resolution. LEDs light / flash to indicate the voltage. All 5 LEDs light when the batteries were fully charged and 1 LED (from the left) flashes while the battery is almost empty. Meter will shut off after displaying for continuous 30 seconds and re-start by pressing the "on" button.