4 pack rechargeable D size batteries, replaces single-use D batteries in low-drain electronics. Tenergy's Centura Lite size D batteries have 3,000 mAh capacity. Rechargeable up to 2,100 times without significant capacity lost. Centura Lite batteries have low self-discharge, these D size Batteries will retain 85% of capacity when properly stored away and not used. Use batteries when first received, or fully recharge them for the best experience. These batteries are UL certified and include 12 months warranty.