The arms race of flash charging is still one charging gun short.

In March 2025, BYD raised the charging rate of its batteries to 10C, claiming that it could achieve "5 minutes of charging to deliver 400km of driving range", and named this technology a straightforward name: Flash Charging.

Since its release, doubts have never ceased.

For one thing, 10C is the peak rate, which usually can only last for dozens of seconds and cannot run through the entire charging process. For another, flash charging requires not only 10C batteries, but also megawatt-level charging piles. However, the maximum power of most fast charging piles on the market is only around 200kW. This means that even with a flash-charging vehicle, it is difficult to experience the real flash charging speed. In addition, the safety and battery life of flash charging batteries are more difficult to guarantee than ordinary batteries.

A year and a half has passed, these problems remain unsolved, but more and more players have entered the track.

This September, Geely released the "AI Smart Charging" technology. Paired with the mass-produced 12C Shield Golden Brick Battery, it only takes 4 minutes and 30 seconds at the fastest to charge from 10% to 70% state of charge.

Li Auto is also betting on flash charging. At a recent communication meeting, Liu Zhimin, Senior Director of Li Auto Power Battery, revealed that the company is pushing forward the vehicle verification of 15C batteries, and the relevant technical preparation is expected to be completed in 2027. Meanwhile, Sunwoda, which manufactures cells for Li Auto, released the "Intelligent Flash Charging Battery System Solution", covering 15C batteries, battery management systems, megawatt-level charging piles and energy storage cabinets, and plans to cooperate with automakers and charging operators to build 10,000 megawatt-level flash charging stations by the end of 2027.

CATL has also launched its own flash charging solution. Its third-generation Shenxing battery has an equivalent charging rate of 10C and a peak rate of 15C, which is expected to be mass-produced by the end of this year.

Around the goal of "making charging as fast as refueling", the "flash charging arms race" in the automotive industry is in full swing.

From 1 Hour to 5 Minutes: How Flash Charging Is Realized

Five years ago, it took more than an hour to fully charge most of the battery of an electric vehicle with mainstream fast charging piles. In the past two years, vehicles, batteries and charging piles have been upgraded together, shortening this time to less than 10 minutes.

Charging power equals voltage multiplied by current, and there are only two ways to increase charging speed. It can be imagined as filling a pool with a water pipe: increasing the voltage is like raising the water pressure to fill faster; increasing the current is like making the water pipe thicker to get a larger flow per unit time.

In the past few years, the industry has advanced on both tracks: the vehicle platform has been upgraded from 400V to 800V and 1000V, and the battery rate has risen from 2C to 4C, 5C, and now even exceeds 10C.

C-rate, the ratio of charging current to battery capacity, is often used to measure charging speed. 1C means full charge in one hour, 10C means 10 times the speed, that is, 6 minutes.

It should be noted that the C-rate advertised by manufacturers is usually the peak rate, which does not run through the whole process. In actual charging, the battery management system will adjust automatically according to the battery status: at the initial stage, a smaller current is used for "warm-up", then the power gradually rises to the designed peak value. After the cell temperature rises, the power will gradually drop, and finally the last part of charging is completed with trickle current. For this reason, the charging time announced by automakers usually takes the most efficient interval in the middle (such as 10% to 70%), avoiding the first and last stages.

Why is flash charging so difficult? The essence of charging is that lithium ions start from the positive electrode, pass through the electrolyte and separator, and intercalate into the negative electrode. The larger the current, the faster the lithium ions migrate, and the more likely they are to "get stuck" on the surface of the negative electrode, failing to intercalate in time, and directly reduce to metal lithium for deposition. The metal lithium may even grow into dendrites, pierce the separator, cause internal short circuit and bring safety risks. At high temperature and high voltage, side reactions such as electrolyte decomposition and gas production will further accelerate the aging of cells.

The solutions of various manufacturers can be roughly divided into three levels: material, structure and algorithm.

At the material level, make it easier for lithium ions to enter the negative electrode and reduce heat generation. For example, CATL improved the SEI film and graphite structure on the surface of the negative electrode, and adjusted the electrolyte formula to improve ion migration efficiency and reduce polarization.

At the structure level, heat dissipation is strengthened, and the previous cooling method that mainly cools from the bottom of the battery is upgraded to double-sided and multi-sided cooling, which extends to the entire charging link.

At the algorithm level, the charging current is adjusted in time according to the temperature and health status of the battery. For example, Sunwoda's smart cell 3.0 not only monitors voltage and temperature, but also monitors impedance, expansion force and air pressure, so that the system can obtain more information to judge the abnormal and aging status of the battery.

In terms of achievements, the figures are quite impressive. BYD raised the peak rate of its flash charging battery to 10C last March. The second-generation Blade Battery released this March further optimizes the problem of slow charging when the battery is almost fully charged on this basis, realizing charging from 10% to 70% in 5 minutes and 97% in 9 minutes.

CATL, Geely and Sunwoda then also launched solutions with higher rates and shorter charging time. Geely's Shield Golden Brick Battery is 12C, CATL's third-generation Shenxing battery has an equivalent rate of 10C and peak rate of 15C, and Sunwoda also launched a mass production solution for 15C batteries in September.

Putting the data disclosed by all parties together: Sunwoda claims that its charging speed is as fast as BYD's; Geely is 30 seconds faster than BYD when charging from 10% to 70%, and 20 seconds faster when charging to 97%. CATL goes a step further, taking only 3 minutes and 44 seconds to charge from 10% to 80%, and about 6 minutes and 27 seconds to charge to 98%.

Charging speed is only one pillar of flash charging. The more difficult part is to find a balance between speed, cost and service life. As Liu Liguo, Senior Vice President of Whole Vehicle Electric R&D of Li Auto, said: "Whoever can take the lead in breaking through 15C and reduce the cost; on the basis of the industry's general pursuit of 100,000 kilometers in 6 years, whoever can further achieve 160,000 kilometers in 8 years while maintaining 75% or even 80% of the battery health, these will become new points of technological competition."

This sentence points out another aspect of flash charging: what users ultimately care about is not only fast charging, but also safety, and the battery status after several years.

BYD, the first to popularize flash charging technology, has launched a warranty plan for battery life: the cells of the second-generation Blade Battery have a lifetime warranty, and the battery capacity retention rate is guaranteed in stages. For example, within 6 years or 150,000 kilometers, the battery can be replaced for free if the capacity is lower than 77.5%. Geely upgraded the battery warranty period of its flash charging models from 8 years/150,000 kilometers to 200,000 kilometers. Other automakers have not yet disclosed the warranty plan for flash charging.

The Last Barrier: Charging Guns

BYD and Geely's flash charging models have rolled off the production line, and CATL's third-generation Shenxing battery will also be mass-produced and installed in vehicles by the end of this year. However, there is still one barrier before flash charging is widely popularized.

To realize flash charging, in addition to the high-voltage resistant vehicle platform and batteries that can withstand large current, megawatt-level charging guns that can output high voltage and large current are also required. Such charging guns are far from enough at present.

Data from the National Energy Administration shows that by the end of June 2026, there are 5.009 million public charging facilities nationwide, of which more than 180,000 are high-power charging guns, accounting for only 3.6%. The average rated power of a single charging gun nationwide is 49.4kW. Flash charging requires a single gun power of more than 1 megawatt, which is 20 times of this average value.

Since no one is willing to build them, enterprises can only take the lead. BYD is the fastest, announcing at the end of August that it has built 10,000 flash charging stations, and plans to double the number to 20,000 by the end of the year. Each charging pile is equipped with two charging guns, with a maximum power of 2.1 megawatts. However, according to BYD's plan, 18,000 of these 20,000 stations are to add flash charging piles to existing charging stations, the so-called "station in station".

Geely plans to build 15,000 stations by the end of 2027. CATL packages the Shenxing supercharging piles and chocolate battery swapping into a "supercharging and swapping integrated station", with the goal of building 4,000 stations by the end of the year, but it has not stated how many guns among them can support 15C. Sunwoda has shouted the goal of building 10,000 megawatt-level flash charging stations by the end of 2027.

However, none of the four companies invest in all the stations by themselves like Tesla, and all hope to build the stations together with partners. BYD has partnered with Sinopec, PetroChina, TELD and others; Geely's allies are dealers and franchisees; Sunwoda wants to cooperate with industrial capital, vehicle customers, ecological partners and operators; the first batch of partners of CATL's supercharging and swapping shared network are 6 automakers: Changan, Chery, GAC, Seres, SAIC-GM-Wuling, and BAIC Group. As for how many stations each company builds by itself and how many are built in cooperation, there is no public information available.

No one is willing to take the initiative to build more stations, and the reason is not hard to understand: up to now, charging is not a profitable business.

Monitoring data from China Electric Vehicle Charging Infrastructure Promotion Alliance shows that in the fourth quarter of 2025, the average utilization rate of public charging piles nationwide was only 6.2%, while the industry-recognized profit line is 8% to 10%. Yang Jun, General Manager of CATL's battery swapping business, also admitted that the entire energy replenishment industry is almost losing money, and the utilization rate is abnormally low.

TELD, the industry leader, was established in 2014 and lost money for nearly ten years before turning profitable in 2023. During this period, it gradually shifted from the asset-heavy direct sales model to the asset-light franchise model, and took the sales of charging equipment as its main business.

At the investor communication meeting in May this year, someone asked the spokesperson of TGOOD, the parent company: Industry news says that charging pile operation is barely profitable, how do you maintain profitability? The answer was very tactful: the company's business covers equipment manufacturing, charging operation, as well as energy and data value-added services, and it does not rely entirely on charging service fees.

The 2024 report of Donghai Securities did the math: a 50kW DC pile has an initial investment of 50,000 yuan, and the service fee is 0.5 yuan per kWh. At the break-even line with 8% to 10% utilization rate, the profit per kWh is only 0.055 yuan to 0.124 yuan, and the average payback period is about 4.7 years.

Flash charging stations require larger investment and serve fewer vehicles than ordinary fast charging stations, so it is more difficult to recoup the cost.

In addition to a complete set of charging guns, cables, connectors and cooling systems that can withstand high power, flash charging stations also need to be equipped with energy storage systems designed for peak charging power. This set of energy storage is over-sized for most of the charging time, not to mention the idle periods when no one uses it.

Nanjing Securities estimates that the comprehensive construction cost of an ordinary 120kW DC fast charging unit is at the level of 100,000 yuan. An engineer specializing in flash charging technology told *Yunjian Insight* that the total cost of a flash charging pile with two guns, plus supporting energy storage and construction renovation, is about 1 million yuan.

100,000 yuan vs 1 million yuan, the account of each charging station is thus different. Combined together, it forms a delicate picture: every company says it will build flash charging stations, but every company also wants others to build first. Vehicles and batteries have moved ahead, but charging piles have become a hot potato.

This arms race targeting faster charging speed has just completed the first stage. This stage is a competition on figures: C-rate, minutes and seconds, competing on the big screen at the press conference.

The second half that determines the success or failure of the competition is about who can reduce the cost, ensure the safety and service life of the battery, and build the charging piles at the same time.

At that time, charging the battery fully in 5 minutes will no longer be just an amazing string of numbers at the press conference.

This article is from the WeChat Official Account "Yunjian Insight", written by Liu Yimo, edited by Wang Hailu, and published with authorization from 36Kr.