Potential of Electrical Cells: the Effect of the Experimental Design on the Results

Different methods of estimating the electrochemical cells potential and internal resistance are considered in the context of a series of measurements of the potential versus intensity for a classical electrochemical cell and of a commercial battery. In all considered instances, perpendicular offsets method provided corrections to the regression coefficients (which are ones and the same with internal resistance and electromotive force) balancing the errors from both voltmeter and ammeter measurements and when applied on contractive space ([-1, 1] × [-1, 1]) of transformed data provided even more balanced results. Thus, perpendicular offsets method for finding the simple linear regression line is found to be the best suited for the paired sets of measurements, as concluded from this study.