They keep going, and going, and going. Battery Energizer is used: For use in watches, calculators, handheld devices, keyless entry devices, home medical devices, and more. Keep out of reach of children. If swallowed, immediately see doctor; Keep in original package until ready to use. Dispose of used batteries promptly. Risk of fire. Batteries can explode or leak and cause injury if installed backwards, disassembled, charged, crushed, mixed with used or other battery types, or exposed to fire or high temperature. California only: Perchlorate material - special handling may apply