Renting in Maine, selling a home or buying a ME residence…suddenly new law means you need to have co2, certain kind of fire smoke detectors installed. If you have an old battery operated smoke detector upstair that you can not remember when you changed the battery last, that unit is a patch and not going to cut it anymore. And they work a lot better with a new fresh battery that with the approaching time change, is a good time to replace as a habit. You need hard-wired units and certain kinds. Read more about the new Maine state law going in to effect November 1st, 2009.