This is not an effective analogy. Apple slowed down processors when the battery was not producing enough voltage to run the processor at the normal clock rate.

This is not an effective analogy. Apple slowed down processors when the battery was not producing enough voltage to run the processor at the normal clock rate. This can happen due to old batteries. It can also happen in cold weather, or any other circumstance that results in lower voltages. It's more like, "Imagine if for reduced horsepower when your engine was at risk of overheating, and would not function properly at the standard horsepower".