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)

A method of testing at least one battery cell in a battery power system, comprising:

• applying a test current pulse at a test frequency based on a test frequency setting in a received test frequency setting signal to at least one battery cell, to place an effective alternating current (AC) load on the at least one battery cell;
• receiving an AC voltage signal generated across the at least one battery cell as a result of the test current pulse applied to the at least one battery cell;
• converting the received AC voltage signal to a direct current (DC) voltage signal indicative of a state-of-health (SOH) of the at least one battery cell based on a sampling frequency;
• measuring the voltage of the DC voltage signal to determine the SOH of the at least one battery cell;
• determining a noise spectrum of the at least one battery cell;
• and
• generating the test frequency setting signal indicating the test frequency setting based on the determined noise spectrum as the test frequency setting.

A non-transitory computer-readable medium having stored thereon computer-executable instructions to cause a processor to implement a method for testing at least one battery cell in a battery power system, comprising:

• applying a test current pulse at a test frequency based on a test frequency setting in a received test frequency setting signal to at least one battery cell, to place an effective alternating current (AC) load on the at least one battery cell;
• receiving an AC voltage signal generated across the at least one battery cell as a result of the test current pulse applied to the at least one battery cell;
• converting the received AC voltage signal to a direct current (DC) voltage signal indicative of a state-of-health (SOH) of the at least one battery cell based on a sampling frequency;
• measuring the voltage of the DC voltage signal to determine the SOH of the at least one battery cell;
• determining a noise spectrum of the at least one battery cell;
• and
• generating the test frequency setting signal indicating the test frequency setting based on the determined noise spectrum as the test frequency setting.

A battery monitoring system for testing battery cells in a battery power system, comprising:

• a plurality of battery monitoring devices, each battery monitoring device configured to be coupled to a subset of a plurality of battery cells electrically connected in series to form a battery,
• wherein each battery monitoring device comprises a plurality of current leads configured to be coupled to the subset of the plurality of battery cells assigned to the battery monitoring device to:
• apply a test current pulse at a test frequency based on a test frequency setting in a received test frequency setting signal to the subset of the plurality of battery cells, to place an effective alternating current (AC) load on the subset of the plurality of battery cells;
• receive an AC voltage signal generated across the subset of the plurality of battery cells as a result of the test current pulse applied to the subset of the plurality of battery cells;
• and
• convert the received AC voltage signal to a direct current (DC) voltage signal indicative of a state-of-health (SOH) of the subset of the plurality of battery cells based on a sampling frequency;
• wherein each battery monitoring device further comprises a plurality of voltage leads configured to be coupled to the subset of the plurality of battery cells assigned to the battery monitoring device to measure the voltage of the DC voltage signal to determine the SOH of the subset of the plurality of battery cells;
• a battery monitoring system control unit configured to:
• control each battery monitoring device among the plurality of battery monitoring devices to test a subset of the plurality of battery cells coupled to the battery monitoring device;
• and
• receive at least one battery current measurement from each battery monitoring device among the plurality of battery monitoring devices indicating the SOH of the subset of the plurality of battery cells coupled to the battery monitoring device;
• at least one battery monitoring device among the plurality of battery monitoring devices, configured to:
• determine a noise spectrum of the subset of the plurality of battery cells coupled to the at least one battery monitoring device;
• and
• generate the test frequency setting signal indicating the test frequency setting based on the determined noise spectrum as the test frequency setting.