June 2022 - pmanifold

Recent incidents of fires in electric vehicles – two-wheelers ( e-2w) in particular – have brought focus on the safety of electric vehicles. These incidents have put a dent in the growth of EV market, which needs to be urgently addressed.

Causes of fire in EVs

The sources of fire are varied. While most of the fires originate from the battery (thermal runaway), some of the other causes have also been found such as short circuits and glitches in regenerative braking. There are multiple cells in a battery pack, each loading and ageing slightly differently, which may cause what are called ‘hot-spots’ at specific locations in the pack. The charging-discharging cycles can result in abnormally high accumulation of heat at these hot-spots, leading to rising temperatures. However, a battery engineer of a leading e-2W, says that despite the reality of climate change and that summers are getting hotter, an EV battery made up of lithium-ion (Li-ion) cells requires a temperature rise of more than a100 °C before getting into thermal runaway and leading to fires.

While hot weather conditions and inadequate thermal management systems of the battery can negatively impact performance and shorten life, they do not necessarily cause fires. Manufacturers of most modern Li-ion batteries ensure that they automatically switch off battery operations around 45-55 °C of battery temperature. Even if these safety features aren’t built-in, it’s impossible for the ambient heat and the heat generated by batteries together to result in a spike of over a100 °C.

Preventing fire events with good battery design and protection system

Automotive Industry Standard (AIS) drafted by ARAI address the testing and certification of vehicles and engines used for both automotive and applications. They play an important role in ensuring safer, less polluting, more efficient, and more reliable vehicles.

The standard AIS048 deals with mandatory for battery compliance testing. This was originally used for lead-acid batteries but has been upgraded since for Lithium Ion batteries as well.

There is also a need to have a good battery design to prevent such fire incidents. Cylindrical Lithium-Ion (Li-Ion) cells are a good choice for EVs, which has two internal protective devices: the Positive Temperature Coefficient (PTC) and the Current Interrupt Device (CID) . The PTC protects the cells under external short conditions and the CID protects the cells under overcharge conditions. The casing of the battery should be heat conductive, robust in structure, and have electromagnetic interference (EMI) shielding. The need for effective EMI shielding is especially prevalent in electric vehicles to minimize the associated risks like damage of electrical and electronic components from corrosion, heat, and other challenging conditions.

In the case of an external short circuit, several layers of protection are required such as Battery Management System(BMS) preventive & diagnostic functions, pack fuse, and CID. Batteries also have some sensitive components like MOSFETs, and current resistors that need to be protected. Also, temperature sensors are required to monitor the battery temperatures and alert the user about possible fire risk. Therefore, industry and manufacturers need to spend sufficient time integrating safety features, testing and verifying their products to avoid such accidents in the future.

Regulatory requirements

The Global Technical Regulations are developed under the International Agreement on Vehicle Construction, to which the EU is a Contracting Party. This Agreement currently has 38 Contracting Parties (including the EU, Japan, Russia, Korea, China, India, and the United States of America). The Regulations cover the approval of vehicles’ safety and environmental aspects and are managed by the World Forum for Harmonization of Vehicle Regulations, a permanent working party of the United Nations Economic Commission for Europe (UNECE). In India, The Automotive Industry Standard has over 40 standards published that cover safety from the level of individual components. That testing is concerned with electric vehicle battery safety and lays out requirements of how those batteries must be able to tolerate a wide spectrum of abuse.

Currently, there are AIS156 in-line regulations with AIS136 for the design of electric vehicles and global technical regulations for automobiles and buses. The EVSGTR20 is designed for Phase I of this regulation, which has already been published, and Phase II focuses on electric two-wheelers. Regulations on passenger cars and buses AIS038 (Revision 2) are aligned to EVSGTR20. Regulations have been updated in all other countries in accordance with GTR20.

AIS Standards for Electric Vehicles and Chargers

Standards	Description
AIS-038 – Electric Power Train Vehicles-Construction and Functional Safety Requirements	It includes requirements of a vehicle with regards to specific requirements for the electric power train and requirements of a vehicle Rechargeable Electrical Energy Storage System concerning its safety.
AIS-039 – Electric Power Train Vehicles–Measurement of Electrical Energy Consumption	It helps in measuring the consumption of electric energy by electric vehicles
AIS-040 – Electric Power Train Vehicles – Method of Measuring the Range.	It is a range test for the electric vehicles
AIS-041 – Electric Power Train Vehicles – Measurement of Net Power and The Maximum 30 Minute Power.	It helps in the measurement of the net power of the electric vehicle and explains the working and benefits of the maximum 30-minute power.
AIS-049 – Electric Power Train Vehicles – CMVR Type Approval for Electric Power Train Vehicles.	It is a test of grade-ability for electric vehicles.

As per Deputy Director, ARAI, fire incident is a quality issue against the default because after all, you don’t see every EV battery catching fire, but only a few of them. Therefore, instead of calling on the government to regulate, OEMs need to self-regulate.

India is participating in Phase II of the GTR20, which focuses on heat transfer, water immersion, safety requirements, and more for two-wheeler batteries. For the two-wheeler, the AIS156 was intended for mechanical abuse, thermal abuse, and electrical abuse. Apart from certification and testing, manufacturers need to perform proper design, internal testing, verification beyond certification testing, manufacturing processes, and even pattern recognition charging and discharging.

Ways to extinguish Fire

When the battery is fired, it reaches a temperature of 70°- 90°C. This is shown in various test results. There are many ways to extinguish a fire. There are three ways to put out the fire.

Lower the temperature
Separate oxygen from fire
Remove flammable material

Water cooling is the best method due to its large specific heat capacity (i.e., 4.2kJ/kg°C), it can absorb a significant amount of heat and reduce its temperature. Water also covers the surface of flammable substances, so it can also separate oxygen from the fire.

What can customers do?

Avoid charging the battery immediately after stopping the EV from running. The lithium-ion cell contained in the battery remains hot for some time. Allow the battery to cool before charging.
Use only vehicle-specific batteries and charging cables. Using cheaper local batteries can damage your mobility device.
If the battery is removable, do not place it in direct sunlight or in a hot vehicle. Also, protects the vehicle and battery from extreme temperatures. Batteries and chargers should be stored in a clean, dry, and well-ventilated place. Do not drain or fully charge the battery. Essentially, they should be between 20 – 80%
Regularly check the battery for damage before use, discontinue use and report to the manufacturer if any are defective. Do not use if the battery is extremely hot or damaged

Cooking landscape in India

Approximately 40% (2.8 billion people) of the global population still cooks with either wood, dung, coal, or charcoal. Nearly 84% of rural Indian households cook on stoves that use solid or biomass fuels. In India, women spend an hour every day collecting firewood. This time dedicated to collecting firewood and cooking limits their ability to attend school and generate income. Moreover, women are exposed to toxic pollutants released from the burning of solid fuels (wood, charcoal, etc.).

Also, the burning of solid fuel in inefficient traditional stoves is responsible for the emission of various indoor air pollutants, which have direct and indirect impacts on the health of women and children. According to the Global Burden of Disease estimation, solid fuel burning for cooking accounted for 6 lakh premature deaths in 2019 in India. Thus, it is need of the hour to transition to electric cooking solutions which include access to electricity, and cleaner, more efficient stoves.

Benefits of Electric Cooking

Electric cooking is cost-effective, safer, more energy-efficient, requires less maintenance than conventional cooking methods, and is free of emissions. Additionally, Electric cooking can also make use of solar power in both urban and rural areas. Presently, about 24% of the electricity consumed in India is generated from renewable resources, and planning to expand it to 40% by 2030. This will be more viable in rural areas where the electricity grid may not be very reliable but solar energy is easier to provide.

Some of the key benefits of electric cooking are:

1	Speed – Cooks food 50% faster
2	Energy efficiency – savings in energy consumption and reduction energy usage cost
3	Easy & Precise Control – Achieve desired temperature
4	Safety – No flame, no gas leakage
5	Low maintenance –Change of burners, pipe, and regulators on periodic basis not required
6	Compact – Can be easily transferred from one place to another
7	Improves health – Prolonged exposure to smoke arising from conventional indoor cooking methods adversely impacting health

Despite the benefits of electric cooking only ~5% households use electric cooking devices today.

Moreover, there is a high willingness to shift to electric cooking, however, there are certain barriers which needs to be addressed. Let’s understand what are these barriers!

Barriers to transition to Electric cooking

Getting consumers to adapt to new technology is a tricky proposition anywhere, but when it comes to electric cooking, its adoption remains riddled with more challenges. Affordability remains the topmost one, especially for a household that relies on biomass fuel which is available for free. An electric cook stove (induction to be precise)uses electromagnetism to heat cookware, which means that the utensils have to contain enough iron to generate a magnetic field around them. For a consumer, this not only means bearing upfront costs, as well as maintenance costs, but also the cost of switching to compatible cookware. This is something the majority of the households might not be willing to bear when their existing utensils and source of fuel are working to their convenience.90% of Ujjwala beneficiaries still use solid fuel for cooking.

The flame-based cooking offered by LPG and biomass is an important barrier that needs attention and resolution as chapatis, an integral food item of an Indian meal does not get cooked properly on an electric cookstove. According to a survey conducted by the Stockholm Environment Institute, majority of Indian women surveyed in rural area said they preferred cooking chapatis the traditional way in a clay oven, or over open fire, because it tastes better.

Another critical barrier is thelow-level perception for electric cooking mostly in rural areas. This issue is especially important, because it is this that is at the heart of the successful adoption of electric cooking technology. Consumers are sceptical about electric cooking appliances in terms of meeting their daily needs, durability and safety. Even though, firewood and LPG based cooking is quite unsafe.

In urban areas, there is lack of motivation to use electric cooking appliance. The incremental reduction in cooking cost is not of much interest as there is a high level of satisfaction and security in using LPG/ PNG.

The government of India has made efforts to enhance access to clean cooking energy through the ‘Go Electric’ campaign, launched by the Bureau of Energy Efficiency (BEE) talks about spreading awareness of the benefits of electric cooking in India. The draft National Energy Policy by NITI Aayog also aims to achieve access to clean cooking energy for all by 2022, emphasizing on electric-based cooking. However, this impetus from the government for widespread penetration and adoption of electric cooking is still limited. There is an elemental issue to the government’s plan of powering India’s cooking through electricity which is lack of electricity supply. While huge strides have been made in the area, power supply in most rural areas remains irregular at best. According to news reports, 10 states receive less than 20 hours of power, with nearly 30 million households that don’t receive power. Which brings us to the question — how can electric cooking be adopted if people can’t use it?

Way forward

To help adoption of electric cooking appliances it is important that traditional practices around cooking is understood and either accepted or countered when introducing electric cooking. The value proposition of electric cooking needs to be rightly communicated which requires focused and customized marketing strategies for electric cooking appliances. The varying acceptance patterns for electric cooking by men and women need to be understood and used for targeted communication. Hence, there is a need to build awareness about electric cooking which is not linked to only product features. There is a need for electric cooking industry to invest in social and behavioral research and use the information for product design, diversification and variety and also for marketing communication drive the transition.

Moreover, the potential end-users needs to be correctly identified. Pushing the economically stressed rural households with intermittent power supply may not be the right stakeholders for to start electric cooking uptake. If it has to then it needs to be supported by right financing mechanism. Rather it could be the urban population (including hotels, hospital, office canteens, schools and other institutions) with stable electricity supply that can be targeted for mass adoption. Possibly India may not transition completely to electric based cooking but both forms can co-exist with electric becoming the primary source of cooking. Moreover, if the Government of India develops a dedicated program to promote electric cooking with the participation of all State Governments, electric utilities, and all other related stakeholders and civil society associations to an aim to make electric cooking affordable and user-friendly for lower strata of the society, then electric cooking definitely will see a brighter future.

Month: June 2022

What are the causes and mitigation measures of fire incidents in Electric Vehicles?