Two days ago, Meizu announced its new flagship, Meizu 15 in commemoration of its 15th anniversary. Actually, the company released three smartphones which include Meizu M15,15,15 Plus, of which 15 and 15 Plus support the new mCharge 4.0 fast charging technology. The mCharge 4.0 has a maximum power output of 12V/2A=24W. However, a Weibo user @Feiwei tested the charging efficiency of Meizu 15.
Results show that the Meizu 15 uses the MediaTek PE fast charge protocol and the original charging head (model UP1220S) does not support QC but uses a USB PD fast charge protocol. After 60% of battery life, the measured voltage is more than 8V, the current is less than 2A, and the total power is basically 15-16W. It seems that the 24W peak may be reached at lower battery levels.
If using the QC3.0 charging head, the charging power is only about 2W which is way lower than the most common 5W of most chargers.
If using a USB PD charging head, the power is also less than 10W which makes this charger lower than what the company has packed with the Meizu 15 series.
The conclusion of these tests is that the Meizu 15 series will be better charged with the original charger as it produces more power than other common chargers.