All standard 9-volt battery smoke alarms should be replaced with the new 10-year battery smoke alarms. These new smoke alarms will last 10 years and eliminate the need to remember to replace the batteries annually. New smoke alarms are also sold with carbon monoxide alarms in the same unit. This is a good way to provide the necessary carbon monoxide detection within the same area of the required smoke alarm(s). Smoke alarms are an inexpensive yet important defense against smoke and fire for your family and your house.