Ideal for purchase with bulk ‘Z’ tools DC18RC Li-Ion Rapid Charger charges 18V Li-Ion Compact Batteries in 15 minutes, (3.0 Ah) Batteries in 22 minutes, (4.0 Ah) Batteries in 36 minutes and (5.0 Ah) Batteries in 45 minutes! Optimum Charging System incorporates 3 Active Controls (current, voltage and temperature) that provide an optimal charge and ensures batteries cannot be over-discharged or over-heated during the charging cycle Central Processing Unit (CPU) in battery communicates with charger to analyze battery and charge according to its unique condition Digital Power Display indicates condition of battery and current charge level (-80%, +80%, 100%)