The Plugable Dual USB-C Wall Charger, utilizes USB Power Delivery (PD) protocol to dynamically adjust charging, ensuring safe and efficient power delivery to devices. When devices begin charging, they often draw higher wattage and voltage. This stage activates the charger's blue LED, signaling fast charging. 

As the device's battery nears full capacity, the PD protocol negotiates a gradual reduction in wattage and voltage to prevent overheating and battery strain. At this point, the LED transitions to green, reflecting a shift to standard or trickle charging rates. This adaptive LED behavior helps users visually monitor the charging status while protecting their devices.