Under the double challenges of energy crisis and climate warming, electric vehicles have received widespread attention as an important way to develop a low-carbon economy and implement energy saving and emission reduction, among which the electric vehicle power exchange is the main direction of current research. In this paper, we analyze the development needs of electric vehicles and provide an in-depth analysis of the power exchange mode of electric vehicles. The state of the battery is especially critical in the process of power exchange between electric vehicles. In order to realize the real-time monitoring of the battery health state in the process of electric vehicle power exchange, this paper uses RLS to establish a battery model and perform parameter identification. Then, on the basis of the second-order Thevenin equivalent circuit model, the Kalman filter algorithm is used to estimate the battery health state. On this basis, this paper constructs a real-time battery health status monitoring system for electric vehicle power exchange using sensors, transformers, displays, DSPs, and other components. Through simulation experiments, the percentage error of the equivalent circuit is between -0.4% and 0.3% in both cases.