Analysis on Fire Accident of Electric Vehicle,
Electric Vehicle,

▍Certification Overview

Standards and Certification Document

Test standard: GB31241-2014: Lithium ion cells and batteries used in portable electronic equipment―Safety requirements
Certification document: CQC11-464112-2015: Secondary Battery and Battery Pack Safety Certification Rules for Portable Electronic Devices

Background and Date of implementation

1. GB31241-2014 was published on December 5^th, 2014;

2. GB31241-2014 was mandatorily implemented on August 1^st, 2015. ;

3. On October 15th, 2015, Certification and Accreditation Administration issued a technical resolution on additional testing standard GB31241 for key component “battery” of the audio and video equipment, information technology equipment and telecom terminal equipment. The resolution stipulates that the lithium batteries used in the above products need to be randomly tested as per GB31241-2014, or obtain a separate certification. 

Note: GB 31241-2014 is a national compulsory standard. All the lithium battery products sold in China shall conform to GB31241 standard. This standard will be used in new sampling schemes for national, provincial and local random inspection.

▍Scope of Certification

GB31241-2014 Lithium ion cells and batteries used in portable electronic equipment―Safety requirements
Certification documents is mainly for mobile electronic products that are scheduled to be less than 18kg and can be often carried by users. The main examples are as follows. The portable electronic products listed below do not include all products, so products not listed are not necessarily outside the scope of this standard.

Wearable equipment: Lithium-ion batteries and battery packs used in equipment need to meet standard requirements.

▍Why MCM?

● Qualification recognition: MCM is a CQC accredited contract laboratory and a CESI accredited laboratory. The test report issued can be directly applied for CQC or CESI certificate;

● Technical support: MCM has ample GB31241 testing equipment and is equipped with more than 10 professional technicians to conduct in-depth research on testing technology, certification, factory audit and other processes, which can provide more accurate and customized GB 31241 certification services for global clients.

According to data recently released by China’s Ministry of Emergency Management, 640 fire accidents of new energy vehicle were reported in the first quarter of 2022, a 32% increase over the same period last year, with an average of 7 fires per day. The author conducted statistical analysis from the state of some EV fires, and found that the rate of fire in the non-use state, driving state and charging state of EV are not very different from each other, as shown in the following chart. The author will make a simple analysis of the causes of fires in these three states and provide safety design suggestions.
Regardless of what situation causing the battery fire or explodes, the root cause is the short circuit inside or outside the cell, which resulting in thermal runaway of the cell. After the thermal runaway of a single cell, it will eventually lead to the entire pack catching fire if thermal propagation cannot be avoided due to structure design of module or pack. Causes of internal or external short circuit of the cell are (but not limited to): overheating, overcharge, over discharge, mechanical force (crush, shock), circuit aging, metal particles into the cell in production process, etc.