Electrochemical energy storage has become more power and energy dense in recent years. Many applications demanding energy storage operate in a pulsed manner. The most common chemistries considered for use in these applications include valve regulated lead acid (VRLA), nickel metal hydride (NiMH), and lithium-ion (LI). The University of Texas at Arlington’s (UTA’s) Pulsed Power and Energy Laboratory (PPEL) has assembled three batteries, one of each chemistry, with ~60 V open circuit potentials (OCPs) and is in the process of experimentally characterizing their capacity fade and impedance growth when they are used to drive a high current pulsed load in a 5 seconds on / 5 seconds off pulsed profile. All of the batteries are being discharged and recharged at rates much higher than thier 1C rating. Using standard voltage, current, and thermal diagnostics as well as periodic electrochemical impedance spectroscopy (EIS) measurements, the capacity fade and impedance growth of each chemistry is being studied to understand how the high rate pulsed profile ages the cells. Empirical and lumped element models of the impedance rise will be developed to better understand what is aging internally and how it impacts the usable life of the batteries compared with manufacturers rated life predictions. The experimental and modeling efforts will be summarized and conclusions will be drawn to provide the audience with a better understanding of how each of these technologies ages when used in high rate, pulsed applications.