Lithium Battery Monitoring Lead O-127 Lithium Battery Monitoring Lead O-127 Permanent power sport battery lead with integrated battery status / charge system monitor for 12.8 / 13.2V lithium Monitor charge of your stored power sport vehicle lithium starter battery or confirm if the vehicle charging system is working correctly 2 automatic Modes – Battery charge level monitor (single LED blink mode) & Charging system test (arrow mode) 3 LEDs display ‘full to empty’ voltage range for 12.8V/13.2V Lithium batteries (LFP/LiFePO4/Lithium nano Phosphate); 4th LED warns when vehicle system or connected battery charger is overcharging Battery charge level : LED matching charge level blinks every 10 seconds (long term draw less than 0.2mA) Vehicle Charge system : LED arrow mode activates when charge voltage reaches effective lithium charge range of 14.2V – 14.5V (v green LED) OVERCHARGE warning activates at 14.6V+ SAE charge port with weatherproof sealing cap