Many people will find that the range of electric bicycles will be greatly reduced in winter, especially in the recent extremely cold weather, so that the range of electric vehicles may only reach one-third or even less of the usual range. In order to be able to use it normally, many consumers often use illegal indoor charging, ultra-long charging, etc., to try to alleviate the situation of battery performance degradation. As everyone knows, such illegal operations make the cold winter a high-risk period for electric bicycle fires. So why does a small battery frequently cause fires?
In the early morning of December 6 this year, in a parking shed in a small area of Wuhan, Hubei Province, an electric bicycle suddenly spontaneously combusted, and about 2 minutes later, the fire became bigger and bigger, spreading rapidly, and many electric bicycles around were ignited.
This is the scene of a fire that occurred in the home of a resident in a high-rise community in Shijiazhuang. It can be seen from the picture in ** that the living room of the house was seriously burned, and the reason for this **disaster** was that the electric bicycle was charged indoors in violation of regulations.
According to relevant statistics, the number of fires caused by electric bicycles has been increasing in recent years, accounting for about 10% of all fires in society, of which 80% occur while charging. And 90% of the cases of e-bikes causing people occur in hallways, aisles and stairwells.
During the investigation, the reporter learned that Article 37 of China's "Regulations on Fire Safety Management of High-rise Civil Buildings" prohibits parking or charging electric bicycles in the public foyer, evacuation walkway, stairwell, and safety exit of high-rise civil buildings.
The reporter followed the fire department to visit some communities, and found that violations are still not uncommon. The words "No non-motorized vehicle parking" are clearly posted on the door of this residential unit, but the reporter saw that the hall on the first floor of a unit building was full of electric bicycles. After investigation, firefighters found that there were also illegal parking of electric bicycles in the stairwells of a considerable number of buildings.
Li Gang, Fire and Rescue Brigade of Huai'an Ecological and Cultural Tourism Zone, Jiangsu Provincial Fire and Rescue Corps: The "Regulations on Fire Safety Management of High-rise Civil Buildings" clearly stipulates that electric bicycles cannot be parked in the hall on the first floor. Once a fire breaks out, a large number of toxic and harmful gases will be produced, which will quickly spread up the stairs, posing a great threat to the entire corridor personnel, and it is very easy to create people. You have to arrange for people to get rid of all this at once, and you can't stop here.
Firefighters told reporters that the strict inspection and cleaning of illegally parked electric bicycles is due to the huge potential risks. In order to attract the attention of consumers, recently, Huai'an Fire specially simulated the illegal overcharging test of electric bicycle batteries. At the test site, it can be seen that when the test electric bicycle was charged for about 46 minutes, the lithium battery under the pedal suddenly occurred**, accompanied by smoke coming out, and the electrolyte could be seen leaking. **After about 50 seconds, a flame comes out of the footrest, and the fire grows bigger and bigger. After 1 minute and 30 seconds, the fire entered a state of intense burning. After 3 minutes, the e-bike was burned to the point that only a charred frame remained. During the test, it took only 3 minutes from the time the e-bike** was completely burned out.
Li Gang, Fire and Rescue Brigade of Huai'an Ecological and Cultural Tourism Zone, Jiangsu Provincial Fire and Rescue Corps: About 3 minutes after the electric bicycle**, the flame temperature can rise to about 1200. Once the "thermal runaway" of the e-bike battery occurs, the combustibles in the body will be fully burned during the combustion** process until the chemical reaction is over. If it is indoors, it is very easy to cause the fire to expand and spread, threatening the personal and property safety of the people. 80% of the deaths caused by electric bicycle fires are due to smoke, and from the past cases, like high-rise unit houses, many of them are because they have no time to escape, inhaling a large number of toxic and harmful smoke and causing death.
The relevant person in charge of the fire department told reporters that the quality of electric bicycle batteries is unqualified, the battery is overcharged, the use of second-hand batteries, batteries that have expired in service and illegal modification of batteries and other reasons may cause fires.
In recent years, in order to prevent and effectively control the fire hazards of electric bicycles, the State Administration for Market Regulation has strengthened the supervision and random inspection of electric bicycle products and their batteries, and at the same time disclosed the information of unqualified products to the public. A few days ago, the State Administration for Market Regulation announced the latest results of the national supervision and random inspection of electric bicycle batteries.
Miao Yuchen, Director of the Random Inspection Division of the Product Quality Supervision and Management Department of the State Administration of Market Supervision: The national supervision and random inspection of the quality of electric bicycle battery products is carried out in the field of circulation, and the random inspection involves two types of products: lead-acid batteries and lithium-ion batteries. A total of 141 batches of products were randomly inspected, involving 74 production units in 14 provinces, and 10 batches of products were found to be unqualified, with an unqualified discovery rate of 71%。
The reporter noticed that in this supervision and spot check, there are two main problems in 10 batches of unqualified electric bicycle batteries, on the one hand, some electric bicycle battery safety projects are unqualified, and there may be first-class risks and fire hazards in use. On the other hand, the capacity of some products cannot be tested and cannot meet the nominal or standard requirements, which is a false standard product with capacity.
Miao Yuchen, Director of the Random Inspection Division of the Product Quality Supervision and Management Department of the State Administration of Market Supervision: From the analysis of the reasons for the unqualified situation, the product quality and safety awareness of unqualified enterprises is not strong enough, and the understanding of product standards is not accurate or the implementation is not in place. For the unqualified safety project, the main reason is that the enterprise one-sidedly pursues the high energy and mileage of the battery, and ignores the safety performance and quality control of the battery. For the unqualified performance items, the main reason is that the company's quality control of the key manufacturing process and key raw materials of the battery is not strict enough, resulting in the capacity of the final product not meeting the standard.
During the investigation, the reporter learned that some consumers in life often charge the battery for a long time, sometimes charging all night, and in extreme cases, if the protective device fails, the quality of the battery itself has become the final safety guarantee.
Weikai Testing Technology is one of the testing units of this national sampling. The reporter came here to interview the detection process of the overcharging project. The national standard requires that in the absence of protection devices and long-term charging, the battery sample should not be ** or not ** during the overcharge process and within 6 hours after the overcharge. But this lithium-ion battery starts to smoke in less than an hour of charging**.
Li Daiyuan, Battery Product Testing Engineer of Weikai Testing Technology: In the process of use, daily consumers will have the habit of charging for a long time and forgetting to unplug the charger. There is also the habit of overnight charging, in this case, if the battery protection function fails, there will be a risk of ***, which will threaten the personal safety and property safety of consumers.
After testing, the unqualified electric bicycle batteries of the overcharging project are a batch of new energy power lithium batteries (suspected of counterfeiting) produced by Anhui Patrol Eagle Power Energy Technology and a batch of lithium-ion power batteries produced by GEM (Wuhan) New Energy Automobile Service.
In addition to the unqualified overcharge, the national supervision and random inspection also found that some products were unqualified for short-circuit protection, which is also a project that is easy to cause disasters.
Li Daiyuan, Battery Product Testing Engineer of Weikai Testing Technology: When charging daily, the battery will be taken out for charging, and metal objects such as keys on the body will touch the positive and negative poles, and a short circuit may occur. Or if there is a problem with the line of the car during the ride, there will also be a risk of short circuit. If this test fails, the sample will be damaged after a short circuit and cannot be used again, or there will be a risk of ***.
After testing, the short-circuit protection of a batch of lithium-ion power batteries produced by GEM (Wuhan) New Energy Automobile Service was unqualified. The reporter noticed that the national sampling found that all the electric bicycle batteries that were unqualified in the safety project were lithium-ion batteries.
According to the testing engineer, there are two types of electric bicycle batteries on the market in China, including lithium-ion batteries and lead-acid batteries, and their main difference lies in the different raw materials for the production of electric energy. Compared with lead-acid batteries, lithium-ion batteries not only have high energy density, long driving range, but also a longer service life. However, at the same time, due to the relatively short development time of lithium-ion battery products, the overall quality level still needs to be improved.
The results of this national sampling show that a total of 23 batches of lithium-ion batteries were randomly inspected, 4 batches were unqualified, and the unqualified discovery rate was 174%。118 batches of lead-acid batteries were randomly inspected, 6 batches were unqualified, and the unqualified discovery rate was 51%。The overall failure rate of lithium-ion products is nearly 2 times higher than that of lead-acid batteries.
Zheng Feida, Deputy Director of the Battery Engineering Department of Weikai Testing Technology: The problems of the national lithium-ion battery are mainly focused on overcharging and short-circuit protection testing, mainly because some companies one-sidedly pursue battery mileage and high energy, thus ignoring the safety of the battery itself. The second is that some companies may use some defective products of battery cells in order to reduce costs, resulting in uneven overall safety of batteries. Lithium-ion batteries are high in energy because of their own carrying, and if the product itself is problematic, there is a high risk.
It is understood that there are about 2,000 electric bicycle fires in the country every year, and the data of the national supervision and random inspection of electric bicycles for two consecutive years show that the overall safety project of lithium-ion batteries is relatively serious, which is the main reason for the frequent fire of electric bicycle batteries. The other battery quality problems highlighted in the subsequent inspection have exposed the serious lack of product safety awareness of individual enterprises.
During the investigation, the reporter noticed that another quality problem found in the national sampling of electric bicycle batteries was that the capacity was not up to standard, and it is worth noting that the five products with unqualified capacity were all lead-acid batteries.
According to the testing engineer, as the power of the electric bicycle, the capacity of the battery determines how far the electric bicycle can run, which is a direct reflection of the performance of the battery. Especially in winter, consumers sometimes feel that the battery is not durable, and it is charged more frequently than usualMost of these are related to insufficient battery capacity.
This national sampling found that the rated capacity of the lead-acid battery produced by the nominal cutting-edge energy technology co., LTD. is clearly indicated as 23ah. Capacity test result 2191ah, which is 95% of the stated rated capacity;The rated capacity of the lead-acid battery produced by Yunnan MediaTek Power Supply *** is clearly indicated as 128ah, and its capacity is measured on average 1251ah, which is 97% of the stated value, is a substandard product with unqualified capacity.
Liu Xueliang, battery product testing engineer of Weikai testing technology: Unqualified capacity will lead to insufficient discharge time, and insufficient discharge time will directly affect the mileage of electric bicycles. For example, a 12ah lead-acid battery can run 40 kilometers to 50 kilometers under normal driving if it is fully charged, and it may not even run 40 kilometers if the capacity is not up to standard.
According to the testing engineer, the ex-factory price of lead-acid batteries is mainly affected by the cost of raw material metal lead powder, accounting for about sixty percent of the ex-factory price of lead-acid batteries. In order to raise the terminal price, some distribution companies choose to use shoddy and false standard capacity, which may be one of the main reasons why the capacity of lead-acid batteries for electric bicycles is not up to standard.
Zheng Feida, Deputy Director of the Battery Engineering Department of Weikai Testing Technology: The unqualified results of the national lead-acid battery are mainly concentrated in the 2-hour rate capacity and energy density. Among them, the reason for the disqualification may be that some enterprises are not strict in the preparation and production process or cut corners, resulting in too many impurities in raw materials, and the battery has self-discharge, resulting in the loss of the active material of the battery, and finally causing excessive capacity loss and substandard capacity. Because lead-acid batteries and lithium-ion batteries do not have an advantage in energy, some companies may have false capacity standards and raised them upward, so the final test capacity is not up to standard.
The reporter noticed that the nominal Shanshuiquan brand lead-acid battery produced by Yunnan MediaTek Power Supply was found to be unqualified for two consecutive years.
In order to understand the reason for the failure of the company's spot check for two consecutive years, the reporter followed the market regulators to the company for investigation. The reporter noticed that this company, located in Chuxiong Prefecture, Yunnan Province, is the only local enterprise that produces lead-acid batteries for electric bicycles. The person in charge of this enterprise told market regulators and reporters that the products that their company has been found to have unqualified capacity for two consecutive years are all products processed for a Zhejiang enterprise.
Zhang Lianghua, head of Yunnan MediaTek Power Supply: Last year's batch of products was like this, because we originally had whiteboard batteries for sale, that is, there was only a verbal agreement with the customer. For example, I provide whiteboard products, they print by themselves, in the process of printing, the customer in order to sell a little better in the market, the capacity is a little higher, we gave the customer last year is 203 ampere, the enterprise hit 25 ampere. The problems that have occurred this year are still somewhat similar to last year, 123 amps hit 128 Ah hours.
According to market regulators, this year, the company was found to have 88 lead-acid batteries in one batch of unqualified capacity-related projects, with a value of more than 4,000 yuan. The local market supervision bureau punished the enterprise, confiscated the illegal income, and imposed a value of 15 times the fine. The local market supervision bureau said that it would further strengthen the supervision and random inspection of enterprises.
At present, the State Administration for Market Regulation has instructed the relevant local market supervision and administration departments to seriously deal with the substandard products and their production and operation enterprises under the national supervision and random inspection in accordance with the law, and ordered the enterprises to stop producing and selling substandard products and rectify them within a time limit, and organize rectification and review in a timely manner.
It is understood that this national sampling is the second consecutive year that the State Administration for Market Regulation has carried out national supervision and random inspections since the official implementation of the national standard for electric bicycle batteries.
Miao Yuchen, Director of the Random Inspection Division of the Product Quality Supervision and Management Department of the State Administration for Market Supervision: We will carry out random inspections for two consecutive years in 2022 and 2023. Among them, 2022 is the first time that the national supervision and random inspection of electric bicycle batteries will be conducted, and the unqualified discovery rate will be 22%, and the unqualified rate in 2023 will drop to 71%, the product quality situation has improved significantly. The main reason is that the first national supervision and random inspection will be carried out in 2022, and the unqualified enterprises will be seriously dealt with in accordance with the law, which has also touched the entire industry. In the next step, we will guide enterprises to equip quality and safety directors and quality safety officers as required, and establish a working mechanism of daily control, weekly inspection and monthly schedulingContinue to maintain a high-pressure situation of quality supervision, and seriously investigate and deal with quality violations.
The safety project of lithium battery is unqualified, and the reason is that the manufacturer has done manipulation of raw materials in order to get improper profits. More than 300 million people in China often use electric bicycles to travel, for the safety and health of this huge consumer group, the supervision of problem manufacturers should be stricter. Consumers should also enhance their safety awareness, lithium-ion batteries need to be away from fire, heat, water and other dangerous sources, and cannot charge lithium-ion batteries for a long time and in confined spaces. Lithium-ion batteries shall not be disassembled, replaced or modified without authorization. Also note that you need to use a dedicated battery charger for charging, and you can't use other mismatched chargers at will. To avoid charging the battery for a long time, when the charging indicator shows that it has been charged, it should be removed in time to prevent the failure of the protection function and cause danger.
*: People**).