9 volt batteries are common for use in remote controls and hand held games, but they are most popular for use in fire alarms. Most fire marshalls will recommend changing your smoke detectors at least every year. In order to make it easy to remember, it is helpful to get in the habit of changing them at the same time of year. For instance, every New Year's Eve or every July 4th, etc. Whenever you decide to do it, make sure you place your order for multiple 9 volt batteries in advance from ServiceLighting.com. 6 volt batteries are less common, as they are quite large. They are primarily used in lanterns and large flashlights. They will last a long time, depending on which device they are used in.
