I have built several cameras using the Radioshack Sensor and am very happy with the battery life I am getting. However the local Radio Shack here in Canada recently informed me that the PIR mini alarm has been discontinued:cry-blue:. I was reading the mods for the MS20 and they indicated that battery life is only "4 to 5 days or 10 pics" with to regular alkaline batteries. Is this true? I am getting several months operation out of my radioshack sensors and often only check them once a month at several locations. I have picked up what remaining RS PIR's I could find here but was hoping someone had found a way to incease the battery life of the MS20.