Duracell Pre-Charged rechargeables are the latest in battery technology offering the best of both worlds. Ready to use from the pack & rechargeable thousands of times. Duracell Pre-Charged batteries have a very low self-discharge, meaning they retain 95% of their charge in the pack for up to 12 months. Duracell Pre-Charged batteries can be charged 1000's of times. Which is great for the environment & your pocket & are compatible with all Duracell Battery Chargers. Ready to use out of the pack. Staycharged for over one year. Upto 65 hours use in a PC mouse.