Charging speed in watts (W) indicates how fast a charger delivers power to a battery. Higher wattage means shorter charging times.
Charging speed is determined by voltage (V) multiplied by current (A) to equal watts. A 65W charger delivers more than twice the power of a 30W charger.
Fast charging protocols vary across manufacturers. USB Power Delivery (PD) is a universal standard supporting up to 240W. Qualcomm Quick Charge is common on Android devices. Various proprietary protocols from OnePlus, Xiaomi, and others reach 150W or higher.
Real-world charging times depend on battery capacity and the device's thermal management. A 65W charger on a 5000mAh battery typically reaches full charge in 45 to 60 minutes. Charging speeds usually slow after 80 percent to protect long-term battery health.
Higher wattage chargers generate more heat, which can degrade battery capacity faster over time. Many manufacturers implement health algorithms that limit peak charging speeds to extend battery longevity.