As car batteries age, what happens to their internal impedance?

As car batteries age, their internal impedance tends to increase. This is due to several factors, such as the deterioration of the battery's chemical composition and the development of internal resistance caused by aging components. High internal impedance can lead to reduced performance, such as lower voltage output and diminished ability to supply current effectively.

The aging process affects the electrodes and electrolyte inside the battery, creating conditions that hinder the flow of current. Consequently, as internal impedance rises, the battery's ability to handle heavy loads and recharge efficiently also diminishes. This is particularly important for applications involving electronic systems or starting engines where strong, reliable power is crucial.

Understanding these changes in internal impedance helps in diagnosing battery health and determining when a battery may need to be replaced to ensure optimal vehicle performance.