Patent ID: 7652448

Claim:
A system for modeling a target battery installed on a motor vehicle comprising: a crank started engine; a starter motor for the crank started engine connected for energization to the target battery; a voltage sensor connected to provide measurements of target battery voltage; a temperature sensor providing a measurement of a temperature correspond to target battery temperature; and a vehicle body computer connected to receive the measurements of temperature and target battery voltage and having a stored program implementing an energy flow model for the target battery and stored data relating to mode parameters including target battery rated capacity, model battery corrected capacity and cranking current required for engine start over a temperature range, the stored program being responsive upon execution by the vehicle body computer for, comparing the target battery voltage measurements and predicted battery open circuit voltage to generate an error current proportional to battery current and using the error current and temperature measurements during engine cranking and time to crank to generate an updated battery corrected capacity.