The 5 volt 2.5a charger supports QC3.0 fast charge, and supports the adjustment of multiple voltage and current levels. 5V2.5A means that the charging voltage is 5V, the charging current is 2.5A, and the power is 12.5W, and the mobile phone is less hot in the high current mode, but the speed is slower.
9V2A means that the charging voltage is 9V, the charging current is 2A, and the power is 18W, which is faster to charge, but the phone heats up more.
12V1.5A means that the charging voltage is 12V, the charging current is 1.5A, and the power is 18W. In this mode, the phone heats up more. During the charging process, the charger will judge the charging situation intelligently, adjust the power reasonably, and ensure the charging efficiency and safety.
Power is equal to current times voltage, so 5 times 2.5 is equal to 12.5w, which cannot be considered fast charge