Battery powers Car Com unit when power is interrupted eg.: when the car door is opened or power is lost.
LED Colors:
Green + Red – Normal
Green LED only – Input Power Failed
Green LED Flashing – Low Batteries
Green + Red Flashing – Short Extist
NOT INTENDED FOR USE FOR BUILDING FLOOR LANDINGS with more than 3 floors, use power supply 42PS https://www.mckeeusa.com/product/power-supply/.