The present disclosure relates to a method and apparatus for accurately detecting an operating status of a battery in a battery system, where the method includes determining a charging profile of a battery in a battery system, identifying a constant voltage and a corresponding constant current in a charging cycle of the charging profile, estimating at least one of a decay constant or an internal resistance associated with the battery, using at least one of the constant voltage or the constant current, comparing the decay constant with a first threshold value or comparing the internal resistance with a second threshold value, and detecting an operating status of the battery to be faulty or healthy, based on the comparison.