Reminder before Apple's low battery automatic shutdown

When the battery is low, the iPhone will automatically remind you, and most users may have questions. Why should I remind you when the battery drops to 20%? Because the sound of the low battery prompt is abrupt, many fruit powders have complained about this problem before. Fortunately, Apple has deleted this prompt tone in iOS 12.2, and now it will only remind you by pop-up, and the "low battery reminder" of iPhone is a self-protection mechanism.

If you continue to use the battery when the charge is less than 20%, the activity of the battery will decrease, which will affect the service life of the battery in the long run.