Recently, a systematic way for constructing fractional differential equations was proposed. This was done by introducing an arbitrary parameter \(\sigma \) , measured in temporal or spatial units depending on the type of derivative. In the present work, given the fractional differential equation corresponding to the RC circuit and the experimental data obtained in the laboratory, an analysis of the system behavior is made. We observe, that even in a simple system, there is a small discrepancy between the experimental results and the ordinary mathematical model that represents it. We show, that the given model is best represented by its corresponding fractional differential equation of order \(\gamma = 0.98\) and the value of \(\sigma = 48.7985 s\) .