Real time condition monitoring in Li-Ion batteries via battery impulse response

Li-Ion batteries are suitable rechargeable choices for electric and hybrid electric vehicle (EV/HEV) applications due to their relatively high level of energy and power density. Development of an efficient method for monitoring their online state-of-charge (SOC) and state-of-health (SOH) is of high importance for vehicular applications. The methods used for SOH estimation are mostly based on discharge tests or ohmic techniques which are time consuming and inaccurate for real time usage. The present paper reports on a new method for estimating the SOH of a Li-Ion battery using its impulse response. Having the impulse response of a healthy battery, the proposed method predicts the terminal voltage of a battery using the terminal current measurement. Online comparison of the predicted and measured voltages provides information about the condition of the battery. The proposed method provides a tool to distinguish among the possible faults which may have occurred in the battery.