Ultralife introduced the world’s first long lasting Lithium 9-Volt over 20 years ago, with over 100 million sold. Our Lithium 9-volt battery is a consumer-replaceable battery that lasts up to 5 times longer than ordinary Alkaline 9V batteries and 10 times longer than Carbon-Zinc batteries. It has the highest energy density, flattest discharge voltage curve, longest shelf life, widest operating temperature range, and lightest weight of any comparable 9-volt battery. A 10-year service / shelf life makes our 9-volt battery the choice for major smoke alarm manufacturers for their premium lines of 10-year ionization-type smoke alarms. As a consumer-replaceable battery, consumers can instantly upgrade any application requiring a 9-volt battery.