Li-ion battery is widely applied in transportation and energy storage systems, due to their advantages of long lifespan, high-energy and high-power density. However, fast and healthy charging is critical when the Li-ion battery is applied in transportation due to the user experience and economics. Research has shown that pulse charging is an effective method for achieving both healthy and fast charging. However, existing research lacks the theoretically analysis on the pulse charging frequency affection to the pulse charging, which is critical for practical frequency setting for the Li-ion. To address this issue, this paper theoretically analyses the relationship between polarization voltage and pulse charging frequency, which is the core parameter that affect the fast and healthy charging, based on a dual polarization equivalent circuit model. DP model of a practical 35Ah ternary Li-ion battery is built in MATLAB and pulse charging is carried out. The simulation results are good fitted with the analysis on the polarization voltage and pulse frequency in the paper.