One of our drivers claims to hang his hat on it. I've just noticed if I hit a bump on my way to the first stop, then if I'm at my first stop and the trailer lights run the battery down, I try to start the truck and the battery fails, the xata reboots and so does the camera, as they've lost power. I either pop start it, or I jump it from the reefer. (some drivers will wait for the mechanic... several times in a day on occasion.) Once I'm going, the xata is back up, the camera light is green. I would guess that it uploads the recorded video during the boot process. It has to be flash memory, the video is not gonna disappear because of a power loss so put your tools away. Having a green light is only useful to me to know that nothing has been recorded. When it's already red, and I hit another bump it flashes again, but don't know if it recorded a second time. I finish the day and get in my pickup truck, head home, stop at the gas station, take the turn too fast and feel the truck bump, I instinctively look at the rear view mirror to see if it is flashing.