This paper develops a method and framework for analyzing the tradeoffs between the calendar life and cycle life of battery energy storage used for energy arbitrage in a wholesale electricity market. We implement a linear program to analyze the revenue potential of a battery system participating in the Electric Reliability Council of Texas (ERCOT) electricity market during 2002–2015, and show how the number of charge-discharge cycles performed in a year affects annual revenue potential. Then, we calculate the potential present worth (or the sum of discounted yearly revenues) of battery systems of various discharge durations and roundtrip efficiencies as a function of their calendar life and cycle life, and show how increasing calendar life and cycle life affects present worth. We show that increasing calendar life provides a greater benefit than increasing cycle life for lithium-ion, sodium-sulfur, and vanadium-redox flow batteries, which counters conventional notions about the importance of battery cycle life. However, we find that increasing the cycle life of lead-acid batteries provides a greater benefit than increasing calendar life, because lead-acid batteries have a lower cycle life than other technologies.