This paper addresses the decentralized charging coordination of a fleet of plug-in electric vehicles (PEVs). In particular, we cast the charging coordination task as a constrained multi-objective optimization problem, and we solve it using a novel receding horizon decentralized optimization method based on multi-population games. Our proposed method is able to coordinate the charging process of arbitrary fleets of PEVs, while satisfying hard operational constraints over the system's variables. Our theoretical developments are illustrated through numerical simulations of various PEV- fleets of different sizes.