Energizer A23 Batteries (2 Pack) Miniature Alkaline Small Batteries Energizer A23 Batteries provide reliable power to your important gadgets. These mini batteries are compatible with a variety of devices including your keyless entry system bluetooth headsets and home security systems. Reach for these 12V small batteries when you need replacement camera batteries or a new garage door opener battery. Miniature alkaline Energizer batteries contain zero mercury to reduce environmental impact. Count on Energizer the #1 brand of specialty batteries to deliver dependable long lasting power to your devices.