Battery capacity voltage meter Displays a bar gauge and a numeric voltage or remaining power to show when the battery needs recharging. It also flashes to alert when capacity is below 20%. Sleep mode and blue backlight Can be set to auto off after 10 seconds or to stay on continuously. It can display either the percentage or the voltage. Blue LCD display is easy to read. Builtin reverse protection. Widely used and 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, and motorcycle. Suitable for various battery types Works with ternary lithium battery, polymer lithiumion battery, 3 lithium ion battery, storage battery, water battery, etc. Note: Not suitable for lithium iron phosphate batteries, 1 2 Li batteries in series, or more than 15 Li batteries in series. Use scenarios Golf cart daily use: monitor the main battery and receive a low power alert to prevent unexpected outages. Boat or RV auxiliary battery: keep track of reserve energy to avoid power loss during trips. Car or motorcycle: quick battery check before long trips or during storage to ensure readiness.