Uh....every twentysomething who's living alone has to figure out what a 9-volt is eventually. Fire alarms, yo. I totally get the whole "grizzled old EE" act, bu

Uh....every twentysomething who's living alone has to figure out what a 9-volt is eventually. Fire alarms, yo. I totally get the whole "grizzled old EE" act, but really?