Many smartphone users have experienced their device’s charging pausing at 80%. This is particularly common with iPhone users. However, this feature is designed to extend the battery life of the device. Li-ion batteries lose their performance over time if they are continuously charged to full capacity. Therefore, a system that slows down or stops charging when reaching 80-90% charge level kicks in. This system is called ‘Smart Charge’ and is designed to optimize charging.
For example, phones that stay on charge overnight after reaching 80% will gradually complete the remaining 20%. This process also prevents the device from overheating. If your phone is being used while charging, overheating can shorten the battery’s life. Therefore, when the phone charge stops at 80%, it either stops charging or reduces the charging speed to prevent excessive heating.
How Can We Turn Off the ‘Smart Charge’ Feature?
If you do not like this feature, you can easily disable it in the settings of iPhone and Android devices. On iPhone, follow ‘Settings > Battery > Battery Health and Charging > Optimized Battery Charging‘, and on Android devices, use the options ‘Settings > Battery or Device Care > Battery or Battery Management > Battery Protection or Battery Optimization‘ to disable this feature.
Source: Anker, Apple Explained