Originally Posted by Polaris OBark

Yeah, I have been a fan since the beginning. The Gen 1 version never let me down, and the battery out-lived two Garmin head-unit batteries (Edge 25 and 130).

Near as I can remember, you just turn it on manually when you turn on your Garmin, and then it will go out when you power off the Garmin if you don't turn it off manually first. You will know it is working because of the tiny blue LED that flashes every few seconds.