This is a very general question, there are multiple factors that you need to consider while designing or choosing your system, such as voltage, battery type, power level and ... but in each category, switching frequency, efficiency and termination current are important factors.
Dear khashayar, I appreciate your useful discussion. Specifically, I want to know the features of a good battery charger in terms of THD, Power factor, efficiency as you kindly mentioned, etc. I will appreciate if you share your ideas in this regard.thanks