The individual electrode impedance parameters and internal resistance of a sealed LiC/Li1-xCoO2 lithium-ion rechargeable battery were estimated by a galvanostatic nondestructive technique. Various resistive components of the battery were found to be minimum between state-of-charge values 0.5-0.9. It is expected that the operation of the battery within about 50% of its depth-of-discharge would prolong the charge/discharge cycle life of the battery.