I'm very impressed with your design. Hoping to do something soon. There seems to be a rash of travel trailers being stolen, particularly the fiberglass egg types. Since they all look so much alike, it makes recovery all the more difficult. My plan would be to install a unit somewhere hidden away inside. Power to the phone would not be a problem as it could be wired in permanently. What about power to the circuit board itself? Does it have to run on batterys?