25w or more
Bluetooth headset flash charge, only 2W is enough, charge 5 minutes to use 2 hours. 4000mAh battery, flash charger more than 20W is enough. Flash charger is generally more than 18W. There is also a 9V1A 15W flash charger.
Fast charge and flash charge are both technologies to speed up the charging speed of the battery, but the technical principle is slightly different. Fast charging is nothing more than increasing the power of charging. In the case of a certain battery capacity, increasing the power can reduce the charging time, the greater the power, the shorter the charging time. The flash charging temperature is low, and the fast charging temperature is high. Category of fast charging technology: 1, VOOC flash charge to improve the charging speed of the method has two general directions: improve the voltage and improve the current.
Increasing the voltage will increase the heat generated during charging, accelerate battery aging and may bring safety risks, so the actual effect is not good. By contrast, raising the current is more realistic. VOOC flash charging technology adopts low voltage and high current mode to ensure the safety of charging process. 2, Qualcomm Quick Charge 2.0 Qualcomm Quick Charge 2.0 technology is an upgraded version of Quick Charge 1.0, using a new specification. The charging speed is improved by increasing the current and voltage at the same time.