Energizer® Lithium 9V Batteries offers Superior Performance in devices that requires 9V size batteries. They perform even in the most extreme temperatures -40° F to 140° F. Weighs much less than other batteries and can be used in place of any standard 9V battery. Lithium batteries are the ideal choice for smoke detectors, monitoring equipment and any outdoor devices operated in cold climates.  The value of these batteries are the superior capacity over alkaline batteries meaning they can stay in the field longer before replacement is necessary.  The longer runtime more than makes up for the extra cost and also is better environmentally as there is much less waste.