When the battery is depleted, the phone powers off to protect its components and prevent potential damage. With the built-in battery protection mechanism, the phone will be shut down before the battery reaches a critically low level.
The feature of immediately turning on when being charged when the battery is depleted requires two conditions:
1. The phone must be at 1% battery or lower before powering off and the battery must not be depleted, otherwise, it will not turn on when being charged;
2. The feature of immediately turning on when being charged when the battery is depleted behaves differently with various chargers. It is recommended to use a Xiaomi 67W or higher charger when the phone is off at below 1% battery to utilize this feature. If the phone has been off for a long time (e.g., a newly purchased device), the battery will be in a depleted state, which will require additional time to charge and power on it.