Bill , that's the first thing Swaro suggested and I did switch batteries . I will say they were nice to deal with / talk to .I explained my testing Procedure to Swaro USA and told them to Test the replacement Units before sending them to me . It irks me to buy an $800 item and then have to debug it . I did use sandbags on the roof of my car as a base and always parked within a few feet of my test position . It's tough finding a good test location in the Northeast , but I finally found a place where I can Range over 2000 Yards on trees , buildings , road signs , etc . and where I won't get run over by traffic . Lucky that third unit was the charm , because I was ready to throw in the towel . Just a good idea to Test everything you buy in todays Market : don't buy it and put it away ( like I did with many items in the past ) ....... buyer Beware !