The duration a vehicle needs to run while stationary to replenish a depleted battery varies considerably. Several factors influence this timeframe, including the battery’s initial state of charge, the vehicle’s electrical load, and the alternator’s output capacity. For example, a nearly completely discharged battery will require a significantly longer idling period than one with a partial charge.
While running the engine at idle can, in theory, provide some battery replenishment, it is generally considered an inefficient method. The engine’s alternator, responsible for charging the battery, operates more effectively at higher engine speeds. Furthermore, prolonged periods of idling can lead to increased fuel consumption, elevated emissions, and potential engine wear due to suboptimal operating temperatures. Historically, idling was more commonly practiced, however, modern charging methods are far more efficient.
