The charging speed is related to the fast charging protocol supported by the mobile phone, such as qc mtk and other fast charging protocols, as well as fast charging developed by mobile phone manufacturers themselves, such as oppo Meizu Huawei. There are two kinds of fast and full, low voltage and high current, which is the fast charge that Huawei and OPPO now use, low heat, fast charge, and 20w power. There is also a high voltage fast charge, generally 2a current, with different voltages, now generally 18w and 24w power. The most important thing about the charging rate is the power of the charging head and the support protocol of the phone itself. First, qc4.0 is also low voltage and high current. Look at your mobile phone network parameters, as well as the power of the mobile phone charger, generally more than 10w is fast charging.