Battery cell calibration system and method for aircraft batteries

A method for calibrating a first battery cell of a battery for an aircraft propulsion system, the method comprising:

• executing a charging sequence for the battery, the battery including a plurality of battery cells, the plurality of battery cells including the first battery cell;
• applying an electrical power pulse to the battery during the charging sequence;
• determining a change in cell voltage of the first battery cell by measuring a pulse cell voltage of the first battery cell and an initial cell voltage of the first battery cell, the pulse cell voltage and the initial cell voltage measured during the charging sequence, the pulse cell voltage measured during application of the electrical power pulse to the battery, the initial cell voltage measured prior to application of the electrical power pulse;
• determining a test cell resistance of the first battery cell using the change in cell voltage;
• determining a change in resistance of the first battery cell using the test cell resistance and a baseline resistance of the first battery cell;
• and
• identifying a presence or an absence of an end-of-life condition of the first battery cell by comparing the change in resistance to a resistance threshold value.

An assembly for an aircraft propulsion system, the assembly comprising:

• a battery including a plurality of battery cells;
• a ground-based charger;
• an electrical distribution system including a high-voltage power distribution unit (HVPDU) operable to electrically interconnect the battery with the ground-based charger;
• at least one battery cell voltage sensor operable to measure a cell voltage of a first battery cell of the plurality of battery cells;
• and
• a controller connected in signal communication with the at least one battery cell voltage sensor and the HVPDU, the controller including a processor connected in signal communication with a non-transitory memory storing instructions which, when executed by the processor, cause the processor to:
• execute a charging sequence for the battery by controlling the HVPDU to electrically connect the ground-based charger with the battery;
• determine a change in cell voltage of the first battery cell responsive to application of an electrical power pulse to the battery;
• determine a test cell resistance of the first battery cell using the change in cell voltage;
• determine a change in resistance of the first battery cell using the test cell resistance and a baseline resistance of the first battery cell;
• and
• identify a presence or an absence of an end-of-life condition of the first battery cell by comparing the change in resistance to a resistance threshold value.