WM Motors is deeply involved in "locking the electric door", how to balance user mileage anxiety and safety risks

The Paper's reporter Wu Yuli

Recently, WM Automobile's "lock electric door" has been boiling over. On multiple consumer complaint platforms, many have launched collective complaints against WM Motors.

On February 11, a Weima car owner told the surging news that although the owners have asked WM Motors to solve their demands through various channels, they have not received any official response from WM Motors so far.

The owner of the car said that in order to cover up the safety defects of the battery that may spontaneously combust, WM Car invited customers to return to the store for maintenance and locked the battery without informing the user, which led to a serious contraction in the actual mileage of the vehicle.

He said that more than 600 car owners have complained for more than 7 months, asking WM to replace the power battery with sufficient mileage and no risk of spontaneous combustion, but WM has not been able to solve it for a long time, and after being reported by the media, WM Motors has quietly upgraded through remote OTA, changed or deleted user car data in the middle of the night, creating the illusion of unlocking, but the actual endurance has not improved.

Although the "power lock" incident has been fermented for several months, WM has never publicly responded to this matter.

In fact, the owner's vehicle is "locked" is not a case. Previously, BAIC BJEV EX360 GAC Aean S, GAC Toyota iA5, Tesla Model S and other models have been exposed to the problem of "locking electricity".

What exactly is "locking the electricity"?

The daily so-called "locked electricity" generally has two forms, which are artificial restrictions on the capacity of the power battery and the charging power. Reflected in the owner's use experience, that is, the mileage is reduced and the charging time is extended.

Feng Tao, a research and development personnel of a power battery company, told the surging news that "overcharging" and "excessive discharge" have great harm to the power battery, and the so-called "locking power" is the behavior taken by the car company for the safety of the power battery.

"In fact, when the power battery leaves the factory, many car companies will limit their battery capacity, and control the upper and lower limits of the capacity through the battery management system to ensure that the battery can neither be full nor empty." Feng Tao said, "However, the discharge depth that is limited at the factory cannot be counted in the battery mileage." ”

At present, the "lock electricity" usually refers to the practice that after the owner buys the car, the car company updates the battery management system again to further compress the effective use capacity of the battery. Therefore, some people in the industry will call the "lock electricity" complained by the owner as "secondary lock power".

"The purpose of this is generally to reduce the safety risks such as fire after the battery gradually ages, but this behavior can also be seen that the company is not confident in its own products." Feng Tao added.

The main reason why WM Motors was complained about this time is precisely because it has limited the power battery capacity of the owner. The above-mentioned owner showed the reporter the measured mileage after the battery was locked, and the locked power coupled with natural attenuation, within two years, the vehicle mileage fell from the manufacturer's so-called 400 kilometers to about 200 kilometers measured, which has brought a more serious impact on the daily use of the owner.

WM car lock electricity follow-up mileage measurement, the interviewee provided a picture

In addition, some car companies will lock the power by reducing the charging power of the power battery.

Feng Tao said that after the long-term, large-capacity and high-power fast charging of lithium batteries, the phenomenon of "lithium dendrites" may occur during the reduction of lithium ions. Crystals accumulate over time, and may eventually pierce the diaphragm of the positive and negative electrodes, causing the positive and negative poles of the battery to be short-circuited, thus triggering thermal runaway.

Reducing the fast charging power can alleviate the phenomenon of "lithium dendrite" and improve safety, but the cost is that the waiting time of the owner each time the fast charge becomes longer.

In July 2021, WITHOUT informing customers and with the customer's permission, GAC Toyota Motor Co., Ltd. limited the output power of the car to no more than 60% through OTA online upgrades for a large number of GAC Toyota iA5 models produced before June 2020, and the current in the fast charging mode of the vehicle was reduced from 240A to a maximum of about 100A, which seriously affected the use of car owners.

Behind the lock-in: spontaneous combustion risk and mileage anxiety

Although WM officials did not respond to this incident, many people in the industry believe that the power lock is related to the frequent spontaneous combustion accidents in WM, and the main purpose is to reduce the spontaneous combustion accident of the vehicle by "locking the electricity".

As early as 2020, WM Motors had 4 spontaneous combustion accidents in a month, and WM motor had also responded.

On the evening of October 27, 2020, an electric vehicle caught fire and exploded in the Institute of Mechanics of the Chinese Academy of Sciences in Beijing, which was a WM EX5. Judging from the news reports at the time, the door of the WM EX5 was blown away and the front seats were completely burned. This incident pushed WM Motors to the cusp of the storm.

The day after the incident, WM Motor issued a statement saying that it would recall 1,282 EX5 units produced between June 8, 2020 and September 23, 2020. WM Motor explained in the statement that because the battery is mixed with impurities during the production process, extreme cases may cause the battery cell to short circuit and cause a fire.

But the problem of spontaneous combustion of WM cars has not been solved. Just in the past, at the end of 2021 and the beginning of 2022, there were three spontaneous combustion accidents of WM cars in Zhengzhou, Sanya and Xiamen.

An industry insider told the surging news that in order to cater to the general charging anxiety and improve the mileage in the publicity, some car companies set the depth of discharge is insufficient, and can only lock the power after the vehicle is sold.

He explained, "It can be understood that after the battery is installed, a piece of redundancy should be divided from the total capacity to avoid the safety risk of overcharging and over-discharging, but some car companies leave this redundancy less in order to publicize their mileage." In addition, there are also many statements in the industry that this is likely to be the mileage requirements of some car companies in order to meet the subsidy policy for new energy vehicles. ”

A power battery reliability test engineer told the surging news, "safety risks and mileage are the two most important considerations of the power battery research and development center, in the absence of new breakthroughs in technology, there is a certain degree of contradiction between these two aspects, and this contradiction also promotes the progress of technology." BMS (battery management system) is used to balance safety and battery life, and should not be used by car companies to lock the power or even tamper with battery data, this behavior ultimately hurts the trust of consumers in the entire industry. ”

Responsible Editor: Yes Dong Dong Photo Editor: Chen Feiyan

Proofreader: Yan Zhang