Research and development of model-based battery state of charge indicator

A novel approach to developing a battery state of charge indicator for an electric vehicle is discussed. An approach to determining the state of charge by combing the available data of discharge characteristics of a lead-acid battery with an identification technique based on the battery mathematical model is presented. The basis for the approach is to introduce a nonlinear battery mathematical model, and to estimate the battery state of charge by least squares estimation. This approach was realized by a digital signal processor and its validity was confirmed by simulation tests using data measured during urban driving and road tests.<
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