The present invention relates to a system for smart management of an electrochemical battery using a method of estimating the internal state of the battery, by use of mathematical models for management of an electrochemical battery during operation thereof, and notably for estimating the characteristics of the battery that are not directly measurable. For applications relative to hybrid and electric vehicles, the most interesting internal characteristics are the state of charge (SoC), the state of health (SoH) and the thermal state. Reconstruction of the internal characteristics is done using mathematical models of the batter.