Abstract: In the case of a major breakthrough in battery technology, "endurance anxiety" is still a pain point for winter cars
On December 16, The Company announced the results of the industry's largest winter test of new energy vehicles recently completed, and the results showed that among all the 41 models participating in the test, the overall performance of independent brands was better than that of joint ventures and imported models, ranking in the top 10 by mileage.
It is understood that the winter test project of the new energy vehicle was launched at the end of November, and the test objects include pure electric, hybrid and extended range electric vehicles, covering popular independent, joint venture and imported vehicles, which is the largest winter new energy vehicle test in the industry in recent years.
The test site was selected for the Hulunbuir Winter Automobile Test Site of China Automobile Center. According to public information, there are 120 days a year where the average daily minimum temperature is lower than -20 °C, and the winter car test environment is excellent. The test subjects set by the winter test not only have the endurance, charging, air conditioning, cold start, etc. for the pain points of the winter car, but also include a total of 20 items such as elk test, climbing, ice and snow ring in low temperature and ice and snow environment, and comprehensively evaluate the performance of new energy vehicles in severe cold weather.
There are still challenges in winter cars, and independent brands perform better than joint venture imports
There are many factors that affect the mileage of electric vehicles, including vehicle weight, tires, wind resistance, motor efficiency, etc. The chemical properties of lithium batteries also lead to new energy vehicles being more prone to endurance attenuation in winter.
Zhang Hong, secretary general of the New Energy Vehicle Branch of the China Automobile Dealers Association, said that the lower the temperature, the more viscous the electrolyte will be, which will greatly reduce the activity of the battery, which will cause a significant attenuation of the usable capacity of the battery, which is a natural phenomenon. In addition, in extremely cold weather, the battery in the car will bring hidden dangers and problems of reducing the supply of driving energy because it wants to heat the car, so that the mileage of new energy vehicles in winter is generally shortened.
In the endurance test session, the performance of independent brand models is eye-catching, and 7 of the top 10 models with measured endurance results belong to independent brands. Among them, weilai EC6, Xiaopeng P7, Extreme Krypton 001, Nezha U and other four models have a measured mileage of more than or close to 300 kilometers, which is also achieved under the premise of normal use of air conditioning and warm air.
In general, models with larger battery capacity are more likely to achieve higher range. Many of the models with the highest mileage have battery capacities of more than 90 degrees. It is worth mentioning that the Wuling Hongguang Mini EV has the smallest battery capacity among all 41 models, but it still runs out of the measured score of 103.2 kilometers, the absolute mileage is not high, but the endurance achievement rate ranks first.
The measured results show that among the 34 pure electric vehicles, 23 models with a range of more than 210 kilometers under low temperature conditions, accounting for 68%. According to the commuting needs of most people who do not exceed 30 kilometers per day, it is enough to charge once a week.
However, in the case that there has not been a major breakthrough in battery technology, "endurance anxiety" is still a pain point for winter cars. According to the user survey report jointly released by the authoritative data agency J.D. Power (Jundi) and the Understanding Car Emperor, both new energy vehicle owners and potential buyers have expressed great concerns about winter battery life.
In order to avoid the influence of external variables on the test, the winter endurance test adopts a unified standard. The night before the test, the testers filled all vehicles in the garage overnight. After the test begins, a driver drives the vehicle to complete the high-speed road conditions, urban road conditions and comprehensive road conditions.
During the test, the driving mode of the vehicle is uniformly set to the most economical driving mode and the kinetic energy recovery is adjusted to the maximum, the tire is the recommended tire pressure, and the air conditioning temperature is set to 24 degrees automatically, and the endurance change during the test process is recorded until the mileage reaches zero.
Low temperature charging time increases, and it will take time for the inflection point to arrive
According to the statistical analysis of the China Association of Automobile Manufacturers, in November 2021, the sales of new energy vehicles continued to rise, with cumulative sales of nearly 3 million vehicles from January to November. According to industry analysts, the new energy automobile industry has been driven by policies and gradually turned into a two-wheel drive development of the policy market. However, affected by factors such as winter endurance attenuation and inconvenient charging, some market participants have judged that the inflection point of new energy vehicles has not yet arrived.
The impact of low temperature on winter cars is not only battery life, but also charging. In the winter test of Chedi, the testers calculated the time for the vehicle to charge from 30% to 80% of the electricity in the low temperature environment, and concluded that the low temperature charging time of the new energy vehicles under test increased by an average of 70%.
However, the charging situation of different models varies greatly, and the charging speed of some models under low temperature conditions is still faster than the speed of the official label, and the fast charging time of individual models increases by 257%, which is very obviously affected by temperature. Battery preheating is one of the main factors affecting charging time during cold driving, and the charging speed of the vehicle is significantly accelerated after the temperature rises.
In addition to endurance and charging, the winter test also comprehensively tested the power performance of new energy vehicles, it is worth mentioning that about 80% of electric vehicles did not have significant decline in power in low temperature environments, and only 1 car cold start was abnormal.
Previously, the Ministry of Industry and Information Technology organized new energy vehicles and power battery companies to hold a symposium, requiring joint research and discussion of countermeasures for the extremely cold weather that may occur this winter, and to prepare for technical support and work plans to ensure the normal use of users to the greatest extent. The meeting believes that "problems such as the attenuation of electric vehicle mileage in low temperature environments are problems in the process of industrial development. ”
In order to overcome the problem of winter endurance attenuation, new energy vehicle companies and battery companies have tried different ideas. Many car companies have adopted battery heating, air conditioning system optimization and other ways to improve the performance of battery life at low temperatures, and some companies have tried to introduce larger capacity batteries.
Wu Hui, general manager of the research department of Yiwei Economic Research Institute and president of China Battery Industry Research Institute, believes that the future research direction of car companies should focus on improving the battery cryogenic system, and ensure that the battery can still release a more ideal amount of electricity at low temperatures through technology. The next step is to increase the development of new materials and improve the ability to work at low temperatures; the second is to heat the battery and make the working environment of the battery temperature higher.
The person in charge of the winter test of the new energy model said that through the centralized test of new energy models, on the one hand, it is hoped to help consumers fully understand the performance of mainstream new energy models in extreme scenarios, provide an objective and real reference for buying, on the other hand, it is also hoped that by paying attention to the new energy winter problem, we also hope to discuss with the industry "how to overcome the winter hurdle" and help the development of the new energy automobile industry.