In 2014, the VOOC flash charging technology launched by OPPO officially opened the door to fast charging for the smartphone industry. In the following years, VOOC flash charging has also occupied the absolute dominance of charging. But in the past two years, many companies came in with various technologies to compete with OPPO. At this moment, all flagships phones adopt this or that fast charging technology. So our friends from pcpop decided to compare the most impressive phones in the Chinese market.
The selected models include the Huawei P20 Pro, the Xiaomi Mi MIX 2S, the VIVO X21 Black Gold Version, and the OPPO R15 Dream Red Version. As you see, all smartphones are the top-end devices. Moreover, each of them supports any fast charging technology. Before we start comparing the charging performance of all models, you should get acquainted with the battery capacities and the fast charging options.
The VIVO X21 Black Gold Version sports a 3200mAh battery and supports fast charging. The OPPO R15 Dream Red variant is packed with a 3400mAh battery that supports VOOC Flash Charge 5V/4A. The Huawei P20 Pro is equipped with a 4000mAh battery, which supports SuperCharge (4.5V/5A). And finally, the Xiaomi Mi MIX 2S is equipped with a 3400mAh battery supporting Quick Charge 3.0 (9V/2A).
The screenshot below shows, in the first ten minutes, almost all smartphones showing the same charging speed at the low power. However, OPPO and Huawei handsets began charging faster due to the 18W input power. The situation changes after 30 minutes. The OPPO R15 Dream Version and the VIVO X21 Black Gold Variant reached 56% and 51% of power, respectively. The Huawei P20 Pro’s charging slowed down because of a larger capacity. That’s why the Xiaomi Mi MIX 2S became the third.
After charging 40 minutes, the phones’ temperatures were measured (from left to right: Huawei P20 Pro, Xiaomi Mi MIX 2S, VIVO X21 UD, and OPPO R15 Dream Edition).
After one hour of charging, because of various charging technologies and battery capacities, the phones showed quite different results. To understand their charging efficiency, we multiplied the standard battery capacity with the charging percentage. So we came up with the highest charging efficiency per unit time.
- Huawei P20 Pro: 4000mAh x 74% = 2960mAh
- Xiaomi Mi MIX 2S: 3400mAh x 85% = 2890mAh
- Vivo X21: 3200mAh x 88% = 2816mAh
- OPPO R15 Dream Edition: 3400mAh x 91% = 3094mAh
It turns out the OPPO R15 Dream Red version has the highest charging efficiency per unit time. The Huawei P20 Pro is the second on the list. The Xiaomi Mi MIX 2S and VIVO X21 UD are the third and fourth, respectively. But the gap between the last two models is very small.