Reducing or avoiding noise in measured signals of a tested battery cell(s) in a battery power system used to determine state of health (SOH)

摘要

Reducing or avoiding noise in measured signals of a tested battery cell(s) in a battery power system is disclosed. A battery monitoring device(s) coupled to a tested battery cell(s) applies test current pulses at a predetermined frequency to place an effective alternating current (AC) load on the tested battery cell(s). The resulting AC voltage signal generated across the tested battery cell(s) is sampled at the frequency of the test current to convert the AC voltage signal to a direct current (DC) voltage signal to be measured to determine the state-of-health of the tested battery cell(s). To avoid or reduce noise in the DC voltage signal, a noise spectrum of noise signals at defined frequencies induced on the tested battery cell(s) is determined. The battery monitoring device sets the frequency of the test current pulse at a determined reduced-noise frequency to avoid noise signals being present in the DC voltage signal.