How does an electric vehicle catch fire? The risks are in the charging phase!

1 Electric bike charger frequently causes fire

In April of this year , an electric bike shed in a university campus in Fujian suddenly caught fire in the early hours of the morning. Hundreds of bicycles and electric bicycles were burned. Some of them were burned and only skeletons were left. Many burned electric bicycles were also connected to the charger. The department initially determined that a fire was caused when the electric bicycle was charged. Fortunately, this fire did not cause any casualties.

In October 2015 , a fire in Haikou City, Hainan Province, was not so lucky. Ten people were sent to the hospital for treatment due to inhalation injuries. Three of them were seriously injured. The culprit of this fire is also the electric bicycle that is charging.

2 Electric vehicle fire accidents continue to rise

As the number of electric bicycles soars, the number of fires caused by electric bicycles nationwide is also rising. Only 2011, 2012, 2013 for three years, fire departments around the country statistics, there are 799 electric bicycles fire from as much as a total of 95 people were killed and 58 people were injured.

At present, the social possession of electric bicycles has exceeded 200 million vehicles, and the probability of an electric bicycle in an electric vehicle every year is two-hundredths of a million. It is worth noting that survey data provided by fire departments throughout the country show that 75% of electric bicycle fires occur during charging.

3 a fire occurred in the electric bicycle charging phase

Seventy-five percent of electric bicycle fires occur during the charging process: charger overload and short circuit of electrical lines are the main causes of fire.

The inspectors indicated that there should be enough overload protection devices inside the charger of the electric bicycle. In the event of an abnormal fault such as a short circuit, reverse connection or overheating, the protection device can quickly blow or block the current input, so as to effectively prevent fire and other dangerous situations. occur.

In a risk monitoring, 23 batches of 30 batches of samples showed circuit overheating, fire, explosion and other dangers in the test of abnormal work items, and the non-conformance rate was 76% .

After analyzing the internal circuit of each sample, the inspectors found that most of the samples had the problem of jerry-building: 25 samples of 30 batches of samples did not install any protective device on the AC power end, and the non-conformance rate was 83.3%. .

4 part of the security risk can be solved by a few cents

In fact, for manufacturers, the current cost of a fuse on the market is quite cheap, as long as 2 to 3 cents or so, but some manufacturers are in order to save the cost of the few cents, but pass the huge security risk to the consumer .

In addition to the overload protection device, if the plastic housing of the electric bicycle charger has a certain degree of flame retardancy, it can effectively impede the spread of the flame in the event of a fire, which is of vital importance in preventing the occurrence of fire. This risk monitoring also tested the flame-retardant properties of 30 sample shells. As a result , 20 of the 30 batches of samples were completely burned out in the plastic burning test, and the non-conformance rate was 66.7% .

At present, the electric bike battery charger casing uses ABS engineering plastics, while the electric bicycle charger has a large power and high heat, and can easily cause the shell to soften or even burn due to heat.

After the final inspection, it was found that 27 batches of the 30 batches of electric bicycle charger samples monitored this time did not meet the standard requirements, and the non-conformance rate was 90% . Among them, 27 batches of samples whose price is under 100 yuan are all not up to the standard, and the non-conformance rate is 100% .

Our country has not yet established a national standard for electric bicycle charger products. There are only some recommended industry standards. However, these industry standards are not binding, and there is no assessment content for safety indicators. In particular, there is no requirement for the flame retardant properties of casing materials. Because there are no corresponding requirements, then manufacturers will not use the more costly flame-retardant materials for production in the production process, and some companies even directly use recycled materials.

The information in this article comes from the Internet and was reorganized and edited by China Rescue Equipment Network.