I have a cool little cord that Mike Garcia gave me which has plug that goes into the MRT receiver on one end and a 9v battery snap on the other. I can power it off either a 6 x AAA battery holder from the now defunct Radio Shack OR from a 9v battery. Either way I don't have to open the battery compartment and lose the screws in the snow. I must say that is the one part of the MRT design where I do the "V-8 salute" and say "what were they thinking?" The screws should have been captive.