Mobile phone charging speed and mobile phone charging line charging head is related to ① mobile phone must support fast charging and turn on fast charging function ② poor quality wire resistance is too high, will reduce the voltage and current leading to slow charging ③ charging head power is very important, the higher the power, the faster the charging, but there is an upper limit, power = voltage * current. s8 original charging head support 5v*2A (10w) \/9v*1.76A (15.84W) Want to improve the charging speed to meet the above three conditions why use the ipad charging head to charge the iPhone will feel the charging speed is significantly faster, because the power of the mobile phone's original charging head is 5v*1A=5w, The ipad charging head power is 5v*2A=10w, power twice as fast charging my mobile phone is also S8, the original charging head has long been used, I bought a Xiaomi dual USB 18w fast charging head, charging speed has been improved, mobile phone manufacturers to limit your slow charging must have a reason, High-power fast charge must have an impact on the battery and life of the mobile phone, there is no need to blindly pursue high-power and fast charge, even if you give 100w charger multi-restrictions will lead to charging will not be too fast. 2019.11.08 Added that Samsung was scared by note7, s8 only supports the activation of Qualcomm QC2.0 (click for details) fast charge in the state of interest screen or shutdown, and the maximum power is only 18w (counselling). Now support a lot of fast charge mobile phones, Samsung belongs to the more conservative manufacturers (you know), and Samsung in recent years in the domestic market share is getting lower and lower there are reasons, manufacturers themselves, the product itself, system optimization, although it is the flagship machine, I think it is not how to use.