Batteries show non-linear dynamic behavior that depends on different internal and external conditions such as temperature, SOC, state of health (SOH), calendaric age, or runtime . Hence the characterization and accurate modeling of batteries is quite demanding. More drastically, a non-linear response may even challenge the suitability of spectroscopic characterization techniques altogether, since causality may be violated . To evade this argument, the common assumption is made that a system is quasi-causal on the time scale of the experiment or the amplitude of the perturbation. However, when experiments are repeated, the validity of this assumption must be assessed for the comparability of subsequent experiments, in particular if they are used to characterize noise processes .