Phone off, but not dead: How the charging icon works.

• Even when "off," a phone's microcontrollers, power IC, and charging chip remain active in a low-power state to manage charging.
• The Charging IC (Power Management IC) is always awake, managing power flow, ensuring safe charging, and activating a "mini charging OS."
• This "mini charging OS" displays the battery icon, percentage, and animation, monitors charging speed and temperature, all without loading the full operating system.
• This active "low power charging mode" is crucial for safety, preventing overcharging, overheating, battery swelling, and short circuits.

Why It Matters: Reveals hidden tech ensuring safe phone charging when off.