Method and device for testing a battery state in at least one battery

A method for testing a battery state in at least one battery (10), comprising:

• energizing the battery (10) with an electric current having a predetermined frequency, and thereafter measuring a resulting voltage response of the battery (10) as a first impedance test (1) to determine initial resistance of the battery (10),
• acquiring and storing measured results (5) of the first impedance test (1), applying a test pulse or discharge pulse to the battery (10) as a high rate discharge test (3),
• again energizing the battery (10) with the electric current of the predetermined frequency, and thereafter measuring a resulting second voltage response of the battery (10) as a second impedance test (2),
• acquiring and storing measured results (6) of the second impedance test (2), and evaluating (7) the measured results of the first impedance test (1), of the second impedance test (2) and/or of the high rate discharge test (3) to identify any offset with respect to the measured results from which battery state can be inferred so as to identify a faulty battery state.