Mobile phone fast charging is becoming more and more popular. Do you really need such a high-power super fast charging?

     "Charge for 5 minutes, talk for 2 hours" is OPPO's classic advertising slogan;

　　During the MWC2022 conference not long ago, OPPO announced the 150W Super Flash Charge technology, which is said to fully charge a 4500mAh battery in 15 minutes, becoming the "ceiling" of current mobile phone charging power numbers. Although there are no OPPO phones equipped with this technology yet, Realme's 150W light-speed charging has already set an example, telling us that today's mobile phones can really be fully charged in about 15 minutes.

　　But the question is, do you really need such super fast charging? Is the super fast charging advertised by manufacturers really that fast?

　　1. How fast can today's smartphones charge?

　　Maybe you already have the answer to this question in your mind, but I still want to take a look at what the fastest charging experience of smartphones is like today before I hear your conclusion.

　　We have selected recently released smartphones from different brands that rank among the top in charging parameters, including realme GT Noe3, which basically represents Ouga's current highest fast charging level; iQOO9, with the same 120W fast charging as Pro; Redmi K50 Pro, with 120W fast charging driven by the self-developed Surge P1 chip; Red Magic 7 Pro, with a rare 135W fast charging; and Honor Magic4 with 100W fast charging.

　　The charging test was conducted at room temperature, using the phone's built-in charger and data cable. The phone was charged from 1% to 100% (the upper right corner of the phone shows 100%, not fully charged, which will be discussed later). We obtained a set of data, as shown in the following figure:

Actual test of charging speed of several mobile phones

　　It can be seen that these fast-charging mobile phones with a power of more than 100W can be fully charged within 30 minutes, and the fastest one only takes 15 minutes. It should be noted that we tried not to use the mobile phone as much as possible during the test, and just let it charge quietly. This is somewhat different from our daily charging situation. After all, if your boyfriend or girlfriend sends you a WeChat message, you will not not reply just because your phone is charging.

　　Another detail is that the 100% we see may not be a true full charge. The battery often needs to be trickle charged for a period of time before it can be fully charged. The so-called trickle charge refers to charging with a tiny pulse current to ensure that the battery is truly saturated and extend the battery life.

　　The trickle charging time varies from one brand to another, so I added another column to the table for comparison:

How long does it take to fully charge several mobile phones?

　　Taking into account the actual charging scenario and the trickle charging time, today's 100W fast charging takes longer than you expect. Especially for Honor Magic4 Pro, its trickle charging time even reaches 15 minutes.

Honor Magic 4 Pro charging diagram

　　And I don't know if you have noticed that the so-called 150W and 120W do not mean that the power is always kept at such a high level during charging. Often in the initial stage of charging, that is, when the power is relatively low, the charging power is very high and the speed is also very fast, but it also does not reach the maximum power. Most of the time afterwards, it will be stable at an appropriate value for charging, otherwise the heat emitted by the phone may cause safety problems.

　　In other words, 150W and 120W are just theoretical limits, and it is not really possible to be that fast.

Redmi K50 Pro charging diagram

　　2. How do you choose between battery capacity and fast charging?

　　Since the battery capacities and charging powers of the above-mentioned mobile phones are different, it is difficult for us to compare which one has better technology. Take the Realme GT Neo3 for example, it has the fastest charging speed among these mobile phones, but its battery capacity is the smallest and the charging power is the largest. So among these mobile phones, its charging speed is the fastest, isn't it natural?

Actual test charging speed of several mobile phones and the official charging speed

　　The fact is that when people discuss whether charging is fast or not, they tend to overlook the two factors of "charging power" and "battery capacity", especially "battery capacity". When people make comparisons, they usually say, "Look, my phone has a 150W fast charge, it can be fully charged in 15 minutes, isn't it fast?" But in fact, its battery capacity is smaller than others.

Realme GT Neo3 starts charging acceleration

　　This also indirectly confirms one thing, that fast charging and battery capacity are in conflict. Mobile phones with high-power fast charging often have restrictions on battery capacity. Take the realme GT Neo3 as an example. When the official released this phone, there were two versions, one with 150W+4500mAh capacity battery, priced at 2799 yuan (12GB+256GB), and the other with 80W+5000mAh capacity battery, priced at 2599 yuan (12GB+256GB), for users with different needs.

The price of the Realme GT Neo3 150W version is higher

　　This means that if other specifications are the same, the 150W fast charge will cost an extra 200 yuan. If you don't want this 150W fast charge, you can not only save 200 yuan, but also get an extra 500 mAh battery capacity, at the cost of just charging a little longer than usual.

　　Of course, there are exceptions to everything. There are also some mobile phones that have both large batteries and top-level fast charging technology, such as the Redmi K50 Pro. It is equipped with a 5000mAh battery and 120W fast charging. This is because Xiaomi has developed a self-developed Surge P1 chip that supports fast charging of single-cell batteries. And in the same space, a single-cell battery has a larger capacity than a dual-cell battery.

Pengpai P1 tries to solve the contradiction between large-capacity battery and fast charging

　　But in actual testing, Redmi K50 Pro needs more stringent testing conditions to reach the official speed, such as you need to completely turn off the screen to charge in order to get the maximum speed. During the charging process, the operation of "turning on the screen" will seriously affect the charging power. In other words, if you want to recover quickly, you have to let the K50 Pro "charge quietly" and dare not touch it.

These power troughs are because the screen is turned on to check the charging status

　　As for the Red Magic 7 Pro, you have to know that gaming phones will sacrifice some things for the gaming experience, such as the thickness and weight of the phone. Red Magic chose a dual-cell 120W+ large-capacity battery solution, but its thickness reached 9.98 mm, which is not allowed for non-gaming phones.