This paper presents a practical solution to improve the performance and power quality of the smart grid (SG) with a high penetration of plugged-in electric vehicles (PEVs). The random, mobile, and time-variant PEV demands can overload lines, transformers, and distributed generations while the collective impacts of their battery charger harmonics may increase the overall total harmonic distortion (THD) of SG. To overcome these issues, this paper incorporates the optimal rescheduling of switched shunt capacitors (SSCs) and their day-ahead schedules in a recently developed online maximum sensitivity selection-based PEV coordination algorithm with the inclusion of harmonics. This will not only improve customer satisfaction by fully charging all vehicles before 8 A.M. for the next day travel but also reduce node voltage fluctuations, overall THD, and system losses. To check the performance of the proposed approach, detailed simulations are performed on the modified IEEE 23-kV medium voltage distribution network with seven SSCs and 22 low-voltage residential networks that are populated with PEVs with nonlinear battery chargers and industry nonlinear loads.