What impact does turning off the engine without turning off the air conditioning have on the car battery?

[EverettRose]

Turning off the engine without turning off the air conditioning will not harm the engine, but starting the vehicle with the air conditioning on may damage both the engine and the battery. Relevant details are as follows: 1. Vehicle type: Luxury cars with automatic air conditioning have load protection during startup, which generally does not harm the engine; however, for lower-end vehicles equipped with mechanical air conditioning, starting the vehicle with the air conditioning on can impose a significant load, potentially damaging the engine and battery. 2. Gradual effect: Starting the vehicle without turning off the air conditioning causes gradual damage to the engine rather than immediate operational issues. Occasional instances will not cause any problems, but frequent operation in this manner may affect the engine's durability. Previously, engines might have operated for hundreds of thousands of kilometers without issues, but now they may only last a hundred thousand kilometers or so.