Multiple measurement methods were developed for determining a battery degradation level, competing in their efficiency and speed. The simplest of them are based on remaining capacity estimation or serial resistance measurement via short current pulse of appropriate frequency. While others include sophisticated treatment of electrochemical impedance spectra and extend to the hybrid approaches, aiming a deep insight into the degradation processes, compromising between covered frequency range or measurement time and complexity of approach. In this poster, we propose a very robust time domain data treatment method of wide applicability, potentially covering an entire frequency range deploying a current pulse of simplest rectangular shape, achievable with any power source and a relaxation time of a minimal length, suitable to the aimed frequency range. The necessary data acquisition rate, data preprocessing, choice of appropriate weighting function and requirements on adjustable current pulse parameters are the main analysis substances addressed.