Duracell Pre-Charged rechargeables are the latest in battery technology offering the best of both worlds. Ready to use from the pack and 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 5 years.Duracell's DURALOCK technology means these batteries are guaranteed to stay powered for up to 5 years when not being used. This huge leap forward in battery technology has been made possible by improvements in the purity of ingredients and upgrades to the construction of the battery cell meaning less power is lost when in storage.