Energizer, 6V Battery. Special devices require a special level of energy: That's why our zero-mercury Energizer A544 Specialty Batteries deliver dependable power for all your gadgets. Whether it's for your Bluetooth headsets, game controllers, cameras, or medical devices, you'll be confident in making the right A544 Miniature Alkaline Battery choice with Energizer. Try them out and see how these miniature batteries go big when it comes to long-lasting performance.