Method and system for estimating battery open cell voltage, state of charge, and state of health during operation of the battery

A battery management system comprising:

• a memory;
• and
• a controller configured to be operatively connected to a current sensor that measures a current flow through a battery to a load, a voltage sensor that measures a voltage level between a first terminal and a second terminal of the battery that are each connected to the load, and the memory, the controller being configured to:
• receive a measurement of a first current level flowing through the battery to the load at a first time from the current sensor;
• receive a measurement of a first voltage level between the first terminal and the second terminal of the battery that are each connected to the load at the first time from the voltage sensor;
• generate a first estimated open cell voltage (OCV) of the battery at the first time based on the first current level, the first voltage level, and a predetermined model of the battery stored in the memory;
• identify a first excitation level of the battery at the first time based on the first voltage level, the first current level and a cost optimization process;
• and
• identify at least one of a first state of charge (SoC) and a state of health (SoH) of the battery using the first estimated OCV only in response to the first excitation level being below a predetermined threshold,
• wherein the cost optimization process implements a cost function that generates a measurement corresponding to the first excitation level,
• wherein the cost optimization function uses the first voltage level and the first current level as inputs, and
• wherein the cost function is selected to minimize an error between the first excitation level and the inputs.