Aimila Digital LED Battery Indicator and Hour Meter 12V 24V 36V 48V 72V Battery Status Charge Meter Gauge This hour meter works on 12V 24V 36V 48V and 72V Lead-acid Battery and 4.5-90 volt DC power Display Reading: 99999 hours. LED Flash for low charge and high charge warning Make sure your "C" terminal is either connected to the Battery "+" or a Key switch,otherwise meter scans from full to empty then shuts off. Application: Boats, automobiles, motorcycles, ATV, UTV, go carts, Jet Ski, snowmobile, lawn tractors, wood chippers, shredders, pumps, generators, and many more.