Comparison of 10 wireless chargers: Yes! 5W wireless charging can't compare with 5W wire charging

"The era of wireless charging has come..." Lei Jun, founder of Xiaomi, wrote on his microblog.

EMM... The director of consumer electronics also thinks that the current "non plug-in" products, such as wireless charging, have indeed become a big trend! Since the end of last year, major mobile phone manufacturers have released flagship machines that can support wireless charging technology.

First, Huawei released Huawei mate 20 pro, which supports wireless charging, in October last year. Then, in February this year, Samsung released Samsung Galaxy S10 series with reverse wireless charging function, and Xiaomi released Xiaomi 9, which is known as carrying the world's first 20W efficient wireless charging architecture, which is comparable to wired fast charging. At the just concluded 2019mwc world mobile communication conference, Nokia also said that the upcoming Nokia 9 pureview will support Qi wireless charging.

It is worth noting that Huawei mate 20 pro and Samsung Galaxy S10 series have added wireless reverse charging function. In addition, according to a new investor report released by Guo Mingxu, a well-known Apple analyst, Apple will release three new iPhones supporting two-way wireless charging in 2019. What is reverse charging? In Yu Chengdong's words:

When you are on the street and find that your iPhone XS is dead and you don't have a charger, you can use your Huawei mate 20 pro to charge it. In short, it can "over power" other devices that support wireless charging.

But as consumers, we are more concerned about the charging speed of wireless charging than the cool black technology?

Consumer report has tested the charging speed, heating condition and charging difficulty of 10 popular wireless chargers, including Belkin, mophie, lvlian, Beisi, rock, jiletang, Anker, Pinsheng, Yise and tulas.

Charging speed

In charge speed test, the article recorded the percentage of 30 minutes and 60 minutes of charged capacity of 10 wireless chargers charging iphonex and Samsung S8 respectively, and when charging to 100% of the total power consumption, the "wired charging" was added as the control group.

The results show that none of the 10 wireless chargers can charge the iPhone from 0% to 40% in an hour. This means that their 1 hour charge is difficult to meet the consumers' moderate use of 5 hours.

It is worth mentioning that after the 12W adapter is connected to the data line, it will take 2 hours and 12 minutes to fill the iPhone. When connected with the wireless charging of the fastest measured music hall, it takes 3 hours and 38 minutes, which is nearly 1.5 hours. From the same power point of view of the input, the energy conversion rate of wireless charging is not high, and the power of the output is far lower than that of the input.

What's more, the nominal maximum output power is 7.5W, and the Belkin and mophie available on Apple official website charge time is even slower than the wired charging time of the 5W charging adapter standard of iPhone x for nearly an hour. The remaining eight products are marked with "5W output", "10W output (max)" and so on. From the actual charging time, none of the 10 wireless chargers have reached the level of "5W wired charging", which is suspected of misleading consumers.

Comparing the charging data of Samsung S8 and iPhone, we found that after 8 wireless chargers are equipped with "9V 1.67a" power adapter (about 15W), the time of full S8 is about 3 hours; With a 12W adapter, the full iPhone takes about 3 hours and 45 minutes.

This conclusion is also in line with the reality, because the higher the input power is, the higher the output power is, the higher the charging efficiency is under the condition that the conversion efficiency is not large. This magazine suggests that consumers with fast charging requirements can pay attention to whether the wireless charger of the mind supports high-power power adapter when purchasing.

Heat condition

The energy radiation of wireless charging is divergent. As a new energy transmission mode, what will its heating situation be?

For this reason, the positive center temperature of 10 wireless chargers for 60 minutes and 90 minutes is recorded in this journal; And they charge the iPhone X and Samsung S8 to 40 percent of the battery, 60 percent of the phone's back temperature.

iPhone 12 charger


0 º To 35 º C is the official operating temperature of the iPhone X. Considering that some people have the habit of charging and operating mobile phones, 35 ℃ is listed as the heating assessment point of wireless charger.

The temperature data show that the surface heating temperature of green couplet, Pinsheng, Qile hall and Beisi are below 35 ℃, which will not bring obvious "warm feeling" to the hand.

However, Anker, ESR, mophie and Belkin have more than 35 ℃ temperature data. Especially for the mobile and Belkin available on Apple official website, the temperature of both of them is over 38 ℃, and they have a more obvious heat feeling. And they claim to have a maximum power of 7.5W, but it's even hotter than Apple's 12W power adapter and Samsung 15W power adapter.

Apple Charger Cable


Comparing the two groups of cell phone temperature data, it can be found that the overall 10 wireless chargers do not bring high temperature rise to the mobile phone when charging. However, Anker, Atlas, rock, ESR, mophie and Belkin were all at higher temperatures than those in the control group. ESR and Belkin charge the iPhone to 60 percent of the electricity, making the phone temperature over 35 ℃.

Scenarios to increase charging difficulty

In order to simulate the influence of mobile phone protection sleeve on wireless charging, during the test, A6 paper is gradually added between the mobile phone and wireless charger. At the moment when the sample can not charge the mobile phone, record the number of A6 paper that has been put in, so as to evaluate the effective (sensible) charging distance of the wireless charger.

iPhone 12 charger


The results show that, except for the outstanding green connection and can withstand 8mm charging barrier, the effective charging distance of 9 products is concentrated in the range of 5.5mm to 6.5mm. Among them, the measured values of Beth and rock did not meet the nominal requirements.

Compared with wired charging, you may encounter such awkward situations when using wireless charger everyday: shaking of desktop or accidentally pushing may interrupt the charging process of wireless charger.

Apple Charger Cable


Considering this, this paper designs a test scene specifically: put the mobile phone in the center of the test sample, and gradually translate the mobile phone in the horizontal direction. At the moment when the sample can not charge the mobile phone, record the distance that has been shifted, so as to determine the effective charging area of the wireless charging device.