This is a tiny and compact digital Battery Level Indicator with LED Display. The 12V Two-Wire Digital Display Battery Level Indicator requires only a few minutes of configuration and is as simple as directly connecting wires to the source you want to measure and seeing the LED blink!!!!
Battery voltage >10.8V, 1 Grid Light
Battery voltage >11.6V, 2 Grids Light
Battery voltage >12.2V, 3 Grids Light
Battery voltage >12.9V, 4 Grids Light
when battery voltage <10.8V , the 4 grids are all off, it means you need to charge the battery right now
The red wire is to connect to the positive pole, the black wire is to connect to the negative pole. No need to worry even if there is any connection mismatch of the wires, the electric circuit won’t be a boom because it features reverse polarity protection.