Why does it take so long to charge the last couple of percentages on the iPhone ?

"With iOS 13 and later, Optimized Battery Charging is designed to reduce the wear on your battery and improve its lifespan by reducing the time your iPhone spends fully charged. When the feature is enabled, your iPhone will delay charging past 80% in certain situations. Your iPhone uses on-device machine learning to learn your daily charging routine so that Optimized Battery Charging activates only when your iPhone predicts it will be connected to a charger for an extended period of time. The algorithm aims to ensure that your iPhone is still fully charged when unplugged."

Learn more about ➔ Optimized Battery Charging

Axel F.

It is to protect the battery after rapidly charging to slow down the last 20%.