A method for estimating equivalent circuit model parameters of a battery may include measuring a battery voltage across terminals of the battery and a battery current drawn from the battery, decomposing the battery voltage and the battery current into a plurality of sub-bands, each sub-band of the plurality of sub-bands based on a time constant that characterizes a temporal behavior of the battery, for each sub-band of the plurality of sub-bands, estimating an equivalent resistance for such sub-band based on a spectral content of the battery voltage and battery current for such sub-band, and estimating an open circuit voltage of the battery based at least on the spectral content of the battery voltage and battery current present in one of the plurality of sub-bands and the equivalent resistances of the plurality of sub-bands.