Energizer MAX, 4 pack size “C” alkaline batteries. Long-lasting power and innovation is what the Energizer MAX family is all about. Energizer C batteries hold power for up to 10 years while in storage, so you have power when you need it most. When it comes to toys, portable radios, flashlights, and other valuable devices, you can feel confident knowing you have the long-lasting power and protection you expect from Energizer.