We analyze the impact of different electric vehicle (EV) charging strategies on the German power system in the year 2030 by explicitly including neighboring countries. A novel parametrization approach dealing with the weekday dependent variations of EV demand is introduced. Investigating a broad interval of CO2 prices yields robustness against varying merit order curves. The underlying nonlinear relationship leads to qualitatively different impacts of EVs on power plant dispatch at different CO2 prices. Furthermore, we find that curtailment of renewable energy sources is reduced independently of the charging strategy. Concerning system cost and emissions, the charging strategy vehicle-to-grid proves to be most beneficial. We show that at low CO2 prices, a production increase of emission intense technologies, such as lignite power plants is overcompensated by several other system components.