Duracell CopperTop All-Purpose 9-Volt alkaline batteries are not only dependable, they’re also long-lasting. You can take comfort in a 5-year guarantee in storage with Duralock Power Preserve Technology. They’re great for important devices in your home like smoke and carbon- monoxide detectors. And from storm season to medical needs to the holidays, Duracell is the #1 trusted battery brand of first responders, pharmacists and parents, so you know it’s a battery you can trust.