1. A method for estimating a present augmented state of an electrochemical cell system, the method comprising: making an internal augmented states prediction of the cell where said augmented state always comprises at least one internal state value and at least one internal parameter value; making an uncertainty prediction of said internal augmented states prediction; correcting said internal augmented states prediction and said uncertainty prediction; applying an algorithm that iterates said making an internal augmented states prediction, said making an uncertainty prediction and said correcting; providing an ongoing estimation of said augmented state and an ongoing uncertainty of said augmented state estimation as a result of the application of the algorithm; and ensuring convergence of one or more augmented states to their respective physical values.