Wired
How deeply people rely on mobile phones, the more they are anxious about batteries.
Although every company is actively promoting fast charging technology, it takes more than ten minutes for most people to charge with wired charging.
However, Xiaomi recently launched a charging technology that can charge from 0 to 100% in 8 minutes, which is named Xiaomi 200W “Hyper Charge”.
This is the first time that wired charging has entered the ten-minute era.
It is estimated that many people like me, seeing this crazy charging speed, just want to know the first time:
Will my phone explode after charging so fast?
If you want to quickly charge users while ensuring safety, you need to design technology in all directions, which is a systematic project.
According to the latest data that Xiaomi’s “Hyper Charge” technology can achieve in the laboratory some time ago, a 4000mAh battery charges 10% in 44 seconds and 50% in 3 minutes. Xiaomi also announced a new wireless charging technology: 120W wireless charging, 100% full in 15 minutes.
The great contribution to the realization of these two technologies lies in a carefully modified Mi 11:
First is the charging architecture. Xiaomi changed the wired charging architecture of Xiaomi Mi 11 Pro to three charge pumps with a conversion efficiency of 98.6% to charge in parallel;
The second is battery design. Replace the 5000mAh single-cell battery with silicon-oxygen negative electrode with 4000mAh 10C graphene super fast charge battery, which is charged in series with two batteries;
For 120W wireless charging, a 30V wireless charging chip with advanced process technology is customized.
Finally, the above charging data is realized.
If you have paid attention to the charging solutions adopted by several other Huawei Ov companies, you will find that wired fast charging is basically solving three problems:
The charging performance of the battery itself-achieved by improving the structure and introducing new materials;
The efficiency problem in the charging process-by increasing the current or voltage to achieve a faster pipeline, but behind it, the entire charging architecture needs to be adjusted;
As well as a very important safety issue, to ensure temperature control and stability during the charging process-this requires the design of sufficient heat dissipation and over-temperature protection.
The dual charge pump and dual cell solution launched by vivo in 2019, the picture is quoted from the Internet
In fact, judging from the evolution history of fast charging technology in the past, charging technology is also from the earliest high-voltage solution, which needs to pay attention to the problem of mobile phone heating, to low-voltage and high-current optimization, adopting chargers and wire customization, and finally gradually transitioning to Trying a high-voltage and high-current solution is exactly the three problems that correspond to the above attempts to solve.
In fact, corresponding to the technological transformation of Xiaomi this time, the number of channels is relatively common. For example, three charge pumps are charged in parallel. The fast charge technology of charge pumps uses a DC-DC converter, which means that the current enters the mobile phone through an external charger. The internal capacitor is used as an energy storage element for voltage-current conversion. Previously common products also have Huawei’s 40W super fast charge.
Huawei 40W super fast charging principle, introducing charge pump, picture quoted from the Internet
The highlight this time is more about the battery transformation.
Currently, single crystal ternary cathode materials are more commonly used, which can generally increase the efficiency of lithium ion transfer while reducing side reactions between the material and the electrolyte, thereby improving the cycle performance of the material under high voltage.
This time, in order to improve the thermal stability and electrical conductivity of the battery, graphene materials have been added, so that the battery can be charged at 10C. A single 10C battery can accept a maximum of 100W of power, and 200W can be charged separately by charging two batteries in series.
As everyone knows, the charging speed corresponds to the energy of the battery. When the speed is faster, more “redundancy” will be designed to ensure the speed, and space is sacrificed. You cannot have both.
Therefore, under the premise of a certain thickness of the mobile phone, if you want to design more structures and ensure heat dissipation inside the battery, it will squeeze the battery energy space. Of course, 4000mAh is the calibrated battery capacity of Xiaomi’s Magic 11 Pro. In real life, this is also close to the standard mobile phone battery capacity.
But this still brings the problem of space optimization. Xiaomi engineers said that the improvement of Xiaomi charging technology is mainly due to the use of the latest gallium nitride technology, the switching frequency is doubled from 120W, and many energy storage devices inside can be used smaller; another technology is planar transformer technology , Instead of the traditional winding transformer, the volume of the 200W transformer is smaller than that of the 120W, and it can basically be the same size as the 120W, and it may be smaller after mass production.
We can also see on a promotional image released by Xiaomi that the size of the charger of the Magic Change Xiaomi 11 Pro does not seem to be much different from the 120W flash charge previously provided.
This series of drastic changes will bring more security challenges.
Xiaomi has also made more over-temperature protection designs-Xiaomi engineers called for ensuring the safety of 200W charging, and made more than 40 safety protection designs.
He gave a few examples:
When the motherboard is designed, an independent MCU+ charging algorithm is used. When the charging status is abnormal, such as abnormal communication, software crashes, etc., the MCU can quickly cut off the high-power fast charging path.
Xiaomi has added some corrosion-resistant rhodium-ruthenium alloy materials to the Type-C port, which can greatly reduce the corrosion of the Type-C interface during the fast charging process. In addition, Xiaomi has designed an over-temperature protection detection circuit on the Type-C port. When detecting that the temperature of the charging port is too high, the charging power can be reduced in time or the charging path can be cut off.
However, these designs meet the reality of the current mobile phone market and may have new challenges: every mobile phone manufacturer on the market is developing its own private fast charging protocol, which causes a certain “compatibility” problem. The charger of brand A cannot quickly charge the mobile phone of brand B, and even the charger of brand B + the line of brand A cannot perfectly fast charge the mobile phone of brand B.
There are many friends around us who use two mobile phones every day. Basically, if you want to achieve fast charging, you also need to carry two sets of charging devices. On this basis, various companies have also introduced accessories that support private agreements, such as power banks.
Xiaomi engineers said that although Xiaomi also has its own private protocol, what is different from other companies is that Xiaomi’s fast charge protocol is more compatible and friendly. “Developing Xiaomi’s private protocol on the basis of compatibility with PD and PPS.”
Recently, the National Telecommunications Terminal Industry Association has also received good news. In view of the current status of the fast charging market, the Association also released the “Mobile Terminal Converged Fast Charging Technical Specification”. The agreement mainly proposes a set of UFCS protocol (Universal Fast Charging Specification). , Stipulates a set of interaction flow specifications for mobile phones, cables and chargers.
Its main purpose is to solve the problem that the fast charging standards on the market are complex and changeable and incompatible with each other-although each private agreement is different, through UFCS, the current and voltage can be flexibly adjusted. The agreement standard is led by Huawei, OV, Xiaomi and other leading manufacturers, jointly initiated by the Institute of Information and Communications Technology, and has also received support from upstream and downstream industry companies.
However, at present, it is hard to say whether manufacturers will abandon the private agreement. It is more likely to increase the speed on the previous public fast charging protocol standard to ensure greater compatibility. After all, before major breakthroughs in battery technology, the development of fast charging technology is a necessity for mobile phone manufacturers, and it is also an important part of mobile phone manufacturers’ technological breakthroughs. This is an “arms race” that mobile phone manufacturers must compete.
From a technical point of view, “explosion” does not seem to be too worrying. However, this is a high-power charger after all, and a Mi Fan is very concerned about the problem of tripping in the dormitory:
If I use a 200W charger to charge in the dormitory, assuming that all five members of the dorm are using Xiaomi Quick Charge, will it trip?
The answer is: “Maybe.”
Do you think it is necessary for the charging technology to advance within 10 minutes now that the mobile phone can be fully charged in 20 minutes?
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