Energizer® Lithium Premium™. Long-lasting and reliable power is one of our specialties, so naturally Energizer® is the world’s #1 brand of specialty batteries. For tools and devices that rely on miniature-size power, go with the specialty batteries that so many professionals depend on. Energizer offers a full range of long-lasting specialist miniature batteries. Whether it’s for heart rate or glucose monitors to keyless entry systems, key fobs and watches, our batteries are compatible with the devices that fit your life, so that you can keep going. Energizer® specialty batteries offer extreme reliability and performance, available in a variety of versatile pack sizes, making them the perfect choice for all your small size needs. Plus, with zero added mercury, what more do you need for your speciality device?