During the charging process, the output current and voltage of the charging adapter are dynamically adjusted, resulting in slower charging when the battery is nearly full. Charging to 100% includes three phases:

• Trickle charging: When the phone cannot be powered on due to an extremely low battery level, and battery voltage is also low. The phone is charged with a low current, in order to protect the battery.
• Constant current charging: When the phone can be powered on but the battery level is still low, the phone is charged with a large, stable current, continuously increasing voltage, and a fast charging speed.
• Constant voltage charging: When the battery level is high, the charging voltage reaches its maximum value and remains constant. The charging current gradually decreases to protect the battery, and the charging speed gradually decreases as well.

In general, the charging is faster at lower battery levels. When the battery approaches a full charge, the charging current decreases gradually for safety reasons, and to prolong the battery lifespan, until the battery is fully charged.

This is a normal occurrence, and no cause for concern.