Wired
With the development of smart phones today, fast charging has almost become a standard configuration.
Especially in the Android smartphone camp, mobile phone manufacturers such as Huawei, OPPO, Xiaomi, vivo, etc. all continue to work hard on the fast charging function-from 20W to 120W, and even 200W, which is still in the laboratory, a game from mobile phone manufacturers Our “quick charge war” is staged from time to time.
So here comes the question:
As mentioned earlier, fast charging technology is a system engineering. In addition to hardware products such as devices and chargers, the charging protocol is also a part of it, which stipulates the communication method between the device and the charger.
1. When fast charging “do not ask for fast”
High power is no longer the only force point for fast charging.
Zhang Jialiang, a well-known fast charging expert in the smartphone industry and chief scientist of OPPO VOOC flash charging, said this on the OPPO flash charging open day.
This is indeed a bit emotional.
Once upon a time, domestic mobile phone manufacturers and third-party charging manufacturers carried out extremely fast running around the “charging rate”. In just 7 years, the charging rate has jumped from 20W to 200W all the way-“support for fast charging” has almost become the basic of smart phones. Standard.
What’s interesting is that the domestic “fast charging rate” race started at OPPO. When every company was constantly refreshing the charging rate, OPPO, which started first, slowed down on its own and suspended the power value. renew.
In this regard, Zhang Jialiang said, “When the charging technology develops to a mature stage, whether the user’s pain point solved by the increase in charging speed is that big, this is what everyone needs to think about.”
Not only Zhang Jialiang, but also many industry experts said that fast charging is not just a race of speed, and the anchor point of industry competition is gradually shifting. In addition to “seeking fast”, how to further improve the user’s charging experience is a question that industry manufacturers should consider.
In fact, as the fast-charging industry enters a mature stage of development, the “under the boom” where fast-charging rates continue to rise, it also implies hidden user pain points such as battery safety hazards, battery aging, and confusion in charging protocols; and these The problem has gradually surfaced.
From slow charging to fast charging, charging speed has always been an important subject of competition, and when the industry enters the “post-fast charging era”, seeking speed is not the only focus.
2. Charging safety is becoming more and more critical
“No matter how the charging technology develops, safety is always the primary factor,” said a senior industry expert.
In the fast charging era, faster charging speeds require high-rate charging and discharging of batteries, which speeds up the reaction speed of chemical substances inside the battery. Only the reaction speed of polymer batteries can accept larger currents. Otherwise, high-rate, high-capacity, and high-speed Fast charging of power will bring more safety hazards to the mobile phone charging system.
According to Anker’s consumer research, the pain points of consumers’ demand for chargers have gradually upgraded from faster charging speeds to safer charging experiences.
From the perspective of industry development, the improvement of charging safety mainly includes three aspects-one is to improve the conversion efficiency through new materials; the other is to monitor the battery safety through the built-in power management chip; the third is to use new technologies and structure Design, etc. to inject safety guarantees.
A senior engineer from a veteran mobile phone manufacturer said that in the exploration of new battery materials, silicon-oxygen anode batteries and graphene batteries are the directions for the industry to seek breakthroughs.
From the current battery safety protection measures adopted by various manufacturers, whether it is a mobile phone manufacturer or a third-party charging manufacturer, most of them adopt a built-in power chip to ensure battery safety.
For example, OPPO can monitor the voltage drop in real time through the battery safety detection chip, and intelligently detect whether the battery has internal damage; when Xiaomi released the 100W fast charge, it once stated that the built-in encryption IC, combined with encryption algorithms and other technologies to ensure battery safety; A third-party manufacturer, Anker uses power management chips in the charger.
In terms of new technologies, the OPPO Flash Charging Open Day announced that it will successively introduce a number of security technologies to the VOOC flash charging technology platform, including low-impedance fuses, gallium nitride (GaN) electronic switches, internal string double cells, and sandwich Safety battery, etc. Among them, the sandwich safety battery prevents the internal short circuit of the battery caused by external force damage from the source.
The so-called “sandwich safety battery” refers to the use of composite current collector technology to use a new type of composite material as the matrix, and two layers of aluminum are plated using cutting-edge technology to form a “sandwich” sandwich structure, and then coating on both sides of the structure. Cover a safety protection layer to form a five-layer safety protection structure.
According to the OPPO laboratory test, the sandwich safety battery can pass the acupuncture and heavy object impact test 100% without affecting the battery performance.
It is not difficult to see that for the protection of charging safety, mobile phone manufacturers have gradually penetrated into the battery from the outside, and the research on the battery by the manufacturer is far more than that.
3. Battery technology urgently needs to evolve
Fast charging is essentially a complex system project. This system includes charging adapters, cables, PMIC integrated power management circuits, batteries, and many other aspects. It is far from enough to increase the power of the power adapter.
Previously, due to the limitations of technological development, various manufacturers have worked hard to increase the charging rate on the power adapter. However, as the fast charging rate increases to 65W, or even more than one hundred watts, if the battery technology is not further developed, It is still difficult to fully reflect in electronic products.
Battery technology has become a key point in the current fast charging rate.
A senior industry expert said that the next major change in fast charging technology is likely to be brought about by battery technology. “Of course, battery technology is the most difficult to break through, once a breakthrough will bring qualitative changes to the charging industry,” said industry experts.
At present, various mobile phone manufacturers have different strengths in batteries. Xiaomi is more inclined to start from the dimension of new materials. In March this year, it released silicon-oxygen anode batteries; while OPPO chose to inject AI into battery management to achieve Smart charging.
In OPPO’s view, maintaining the number of active lithium ions is the key to affecting battery capacity, and the negative electrode potential is one of the main factors affecting the number of active lithium, so detecting and controlling the negative electrode potential becomes the key.
According to Tian Chen, head of OPPO’s flash charging team, through three years of research, OPPO has mastered a method that can dynamically obtain and track the negative electrode potential of mobile phone batteries in real time, so that it can intelligently and dynamically control while maintaining the same life. Charging current to obtain faster charging speed.
“The application scenarios of mobile phones are very complicated. To model during normal use of mobile phones, or during low-temperature conditions and battery aging, you need to go through the process of continuous establishment, refresh, and verification, and once new scenarios are discovered, you also need to verify whether there are bugs. , Re-optimize,” Tian Chen explained when talking about the long time spent on research and development.
With the blessing of smart charging technology, OPPO also gave the changes in the core performance indicators of various mobile phone charging, including:
Battery life: guaranteed to be the same as the 65W super flash charging speed, after 1500 cycles of full charge and discharge, the battery has 80% capacity, and the battery life is 3 times longer (compared to the national standard requirements);
Charging speed: support to further intelligently increase the charging speed in specific demand scenarios. In the full blood mode, the charging speed of the 65W super flash charge can be increased by another 20%, and it takes 30 minutes to fully charge a 4500mAh battery;
Temperature rise performance: According to different usage scenarios, it can intelligently predict the current and heating conditions, dynamically match the charging power, and achieve a balance between the charging speed and the temperature rise performance.
4. “Normalization” of fast charge protocol
As mentioned earlier, fast charging technology is a system engineering. In addition to hardware products such as devices and chargers, the charging protocol is also a part of it, which stipulates the communication method between the device and the charger.
In the field of mobile phone charging, there are currently five mainstream fast charging technology manufacturers with charging protocols, namely Qualcomm, MediaTek, USB-IF Association, Huawei, and OPPO. Among them, the first three are public agreements; the latter two are private agreements.
Due to historical factors in the evolution of fast charging technology, the fast charging industry has always had the problem of protocol incompatibility, resulting in only basic low-power charging between branded mobile phones and chargers.
In addition to affecting the user experience of fast charging, the incompatibility of the charging protocol also causes waste of resources to a certain extent, increasing the risk and cost of R&D in the upstream and downstream of the industry chain.
It can be said that due to the incompatibility of the agreement, the fast charging industry has fallen into a competitive vortex of inefficiency and internal friction.
When fast charging was just developed, from the perspective of security, or from the perspective of brand protection, compatibility was not so good, and even encryption was adopted to distinguish responsibilities. By now, (Quick Charge) has been quite mature, and this situation has changed.
Zhang Jialiang analyzed – and the changes in the situation he mentioned point to the “normalization” trend of the charging protocol.
In May of this year, the Telecommunications Terminal Industry Association released the integrated fast charging standard “Mobile Terminal Converged Fast Charging Technical Specifications”, hoping to promote the interoperability of various manufacturers in the fast charging technology agreement. At present, this standard has been supported by terminal manufacturers and supply chain companies such as Huawei, OPPO, vivo, Xiaomi, Honor, Silica, Rockchip, Lihui Technology, Angbao Electronics, and Dianku Networks.
In addition, with the advent of USB-C and the expansion of the USB-PD fast charging protocol, the industry has begun to gradually move towards compatibility. At present, more and more manufacturers have announced compatibility with the PD protocol, including Apple, Samsung, Lenovo, Anker and so on.
It is not difficult to see that the charging agreement that was previously divided into separate packages is slowly closing.
The general trend in the future must be towards unity. Regardless of domestic or global, the charging protocol will be unified, which is a general trend and an inevitable trend.
A senior engineer from a veteran mobile phone manufacturer said.
5. Wired charging may be replaced by wireless
In addition to the above three changes, in our interviews and surveys, many industry experts have talked about another charging development trend-that is, wired charging may be replaced by wireless charging.
In recent years, while constantly refreshing the charging rate of wired flash charging, various manufacturers have also made efforts in wireless flash charging. We understand that since 2018, mobile phone manufacturers including Huawei, Xiaomi, Meizu, OPPO, and OnePlus have successively launched wireless flash charging solutions.
From the perspective of charging rate performance, Xiaomi’s 80W wireless flash charging is at the forefront, followed by OPPO 65W AIRVOOC and Meizu 40W vertical wireless overcharge.
Despite the rapid development and promising prospects, to truly replace wired charging, wireless charging still needs to break through many technical bottlenecks.
According to relevant industry sources, most of the mainstream wireless fast charging on the market can only charge point-to-point short distances, which is low in flexibility and is not a true form of wireless charging.
“Future wireless flash charging should be non-contact, that is, when the mobile phone enters a certain range, it can automatically connect and charge,” said a senior engineer.
In addition, in terms of conversion efficiency, compared with wired charging, wireless charging has low conversion efficiency, high loss, and serious heat generation, which puts forward higher requirements for wireless charging rate and device heat dissipation.
According to estimates by the OneZero and iFixit teams, the average wireless charging uses 47% more power than wired charging. It takes an average of 14.26 Wh to fully charge a mobile phone using a wired method, while an average of 21.01 Wh is required for a wireless charger.
“When the charging speed is close to that of wired charging, and the cost is approaching the range of wired charging, wired charging may be replaced by wireless charging, but these technologies will take some time to overcome.” Anker innovative consumer power product research and development Director Li Mingkang said.
6. Asking for speed is not the only point
Fast charging of smart phones has actually entered a mature stage.
However, this does not mean the “stagnation” of the charging rate increase. On the contrary, it is more like a transition from a fast-paced to a jogging stage-that is to say, the increase in the charging rate is still continuing, but for the improvement of safety The excavation of battery technology also needs to be put on the agenda.
To a certain extent, this is a stage that the charging industry will inevitably go through in a certain period of development. As mentioned in the “barrel effect”, how much water the barrel can hold does not depend on the longest wooden board, but on the shortest wooden board.
In the systematic charging project, the speed increase is also the same. Even with the 100W power adapter, it is difficult to land. It is the limitation of the “short board”; especially when the fast charging technology becomes more mature, the competition Players on the road have to dig deep into the technical level to deal with more difficult challenges.
Of course, from another point of view, when industry players no longer only focus on the increase in the charging rate value, they begin to pay attention to issues that are difficult to bring significant value, such as security and protocol uniformity, indicating that the fast charging industry has begun to “poor.” “Pursuing change” is also getting rid of the perspective of manufacturers’ competition, and getting closer and closer to the actual user experience of consumers-to some extent, this also means that the fast charging industry has begun to enter a state of benign development.
After all, no matter how the technology develops, it will ultimately serve people.
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