Battery Capacity Voltage Meter - Clear monitoring: shows a bar and a numeric value of volts or remaining power on the battery in use, so you know when it must be recharged. It also flashes to alarm when battery capacity is lower than 20%. - Sleep mode and blue backlight: the unit can auto off after 10 seconds or stay displaying either percentage or voltage. Blue LCD display is easy to read, while red display is more readable in bright sunlight. Built-in reverse protection. - Easy to install: small and compact with a rear cover. Simple wiring: connect the red wire to positive and the black wire to negative. Suitable for golf cart, boat, car, RV, motorcycle. - Suitable for various battery types: works with ternary lithium battery, polymer lithium-ion battery, 3- lithium ion battery, storage battery, water battery, etc. Note: Not fit for lithium iron phosphate batteries, 1-2 Li batteries in series and over 15 Li batteries in series. Use scenarios - Golf cart: monitor the battery health and remaining capacity to plan charging stops, reducing the risk of unexpected outages. - Boat: keep track of the house battery to ensure essential electronics and lighting stay powered during trips; the unit’s reverse protection helps guard against miswiring. - RV or car: track starting and auxiliary batteries to decide when to recharge, preventing sudden power loss during travel or camping.