Curious Case of Burning Bikes !!!

The future of the mobility industry lies in the hands of Electric Vehicles or EVs as they say. We can admit that it is one of the promising ways to reduce the heavy dependence of the mobility industry on carbon-rich fossil fuels. A number of countries and companies have already started their journey to harness the power of EVs. India although a new entrant in this domain, is already on the road to becoming one of the biggest EV markets by 2030. It is projected that the EV market in India will be as big as $200 billion by 2030. This will majorly be dominated by the two-wheeler segment, but going by the last six-month reports the picture looks a little gloomy. Several fire accidents have been reported lately, raising many eyebrows regarding passenger safety. It is not restricted to a particular manufacturer, almost all OEMs have seen some kind of heating or fire issues. Hence, the question arises, what exactly is going wrong?

Let us try to dig a little deeper. There are broadly two aspects to the issue in hand, first, technical and other practical. We will start with the technical aspect first. Currently, Li-ion batteries are used owing to their lightweight, high energy density, durability, and rechargeability. However, the energy density of a battery can be both a boon and a bane, the more the energy density less the stability of the battery. This trade-off between energy density and stability leads to a major drawback of batteries, i.e. they are required to operate in a really narrow operating temperature range. The battery cell safety and stability depend on how we maintain the internal temperatures within specific limits. If the temperature crosses a critical value, it leads to a phenomenon called - thermal runaway. Thermal runaway is nothing but a chain reaction within the cell. When the temperature level increases, a chemical reaction is triggered in the cell. This chemical reaction produces enough heat to start a series of chemical reactions, creating more heat. During thermal runaway, the temperature rises rapidly (milli-seconds) owing to the high energy density of batteries, creating extremely high temperatures (400-500degC). Finally this leads to the gassing of the battery or even a fire which can be fatal. Rapid charging, overcharging, high ambient temperatures (Summers in India), and poor cell/assembly quality are some of the key causes behind thermal runaway. We have seen similar fire accidents in mobile batteries before, but the technology seems to be matured in that segment now. Automotive Sector still needs time to address these challenges. The difference in the level of challenges can be estimated by the fact that while mobile battery stores somewhere around 100-200 watt-hours of energy, an EV battery stores up to tens of Kilowatt hours of energy, which is significantly higher, making the battery design for EVs more complex.

One key point which can improve the safety of the battery pack significantly, and is ignored by most manufacturers is proper thermal management and Battery Management System (BMS). BMS works as a control center for the battery pack and ensures that the battery is operating under safe conditions. It is an electronic system that monitors and manages cell voltage, cell current, cell temperature, charging control, and detects any possibility of an internal short circuit. When the temperature of a certain cell shoots up, BMS triggers the thermal management or cooling system where fans around the battery pack run and reduce the temperatures. EV manufacturers like Tesla, Audi, and BMW are using active liquid cooling systems to maintain battery temperatures. But in India where OEMs are struggling to strike a balance between cost, quality, and design, using this type of thermal management system is difficult. It will definitely improve the product but will increase the cost, further widening the existing price gap between IC engines and EVs. Hence, only a few players are using active cooling systems currently, and the majority are deploying a passive cooling system only.

The other reason which holds true specifically in the current scenario is the practical one. What exactly happening in India right now, is majorly driven by the cost of EVs, strict competition, and peer pressure among OEMs. This competition coupled with high market demand has led manufacturers to rush production, not spending enough time designing and testing products, subsequently resulting in poor quality, faulty design, and non-compliance with safety measures. Now OEMs are in some sort of fire-fighting (pun intended) mode, recalling thousands of already sold vehicles and trying to save their brand image. Most of the OEMs are therefore facing huge losses currently. This goes on to show that strong engineering, thorough planning, and proper risk assessment even at the cost of a slightly delayed product launch is much more beneficial in the long run for a tech product company (Ather Energy is a very good example here).

Moving forward, EV manufacturers have to pay more heed to battery design, quality issues, and safety compliance. Our union minister, Nitin Gadkari, also announced that any manufacturer found to be compromising on safety will be penalized heavily. Another major step taken is the Battery Swapping policy proposed in the Budget this year(2022) to support EV manufacturers. As battery chemicals and materials degrade over time, and if someone is using an old, uncharged, or undercharged battery, which may have built up gases, then it is a big safety hazard. This policy will therefore help ensure safety and will also help manufacturers to reduce costs if they can offer battery swapping after a certain period of time. Despite of these initial bumps in its ride, the EV market in India still has lots of upsides. There is still a huge demand for quality EV products, India still has a very big opportunity, and if necessary steps are taken in the right direction, we can still achieve all the big forecasts and beyond.