Lithium battery state of charge estimation method based on unit impulse response

The invention relates to the field of electric automobile battery power, and provides a battery state of charge estimation method through estimation of current open-circuit voltage of a battery. The adopted technical scheme is the lithium battery state of charge estimation method based on unit impulse response. The method comprises the following steps that a group of N discrete points corresponding to various SOC levels of impulse response, i.e. a function, are calculated under the experiment condition of offline calibration firstly and then stored in a lookup table so that the full range of effective SOC values of the battery are evenly divided into n independent values, and each value is corresponding one definite impulse response hn[k]; after the lookup table of impulse response is completed, output voltage of the battery within the given time interval can be calculated via the measured values of working current and the convolution sum of all impulse response stored in the lookup table; and a group of n output voltage in total is calculated as for any one working current, and the SOC of the battery is determined. The lithium battery state of charge estimation method based on unit impulse response is mainly applied to design and manufacturing of the electric automobile battery.