In the 31 second clip, the scooter is seen parked on the roadside of a busy commercial area and is completely engulfed in fire, possibly suffering from a thermal runway. Thermal runaway is an uncontainable exothermic reaction that can occur inside a lithium-ion battery when it is damaged or short-circuited. Once a lithium ion battery is on fire it is also difficult to extinguish. Immediately upon contact with water it produces hydrogen gas and lithium-hydroxide. The hydrogen gas is a significant obstacle due to its extreme flammability.
“We are aware of an incident in Pune that happened with one of our scooters and are investigating to understand the root cause and will share more updates in the next few days,” the company said in a statement to ETAuto. “We’re in constant touch with the customer who is absolutely safe. Vehicle safety is of paramount importance at Ola and we are committed to the highest quality standards in our products. We take this incident seriously and will take appropriate action and share more in the coming days.”
While the cause of the fire in the S1 Pro is being investigated, in most cases batteries catch fire due to poor quality of lithium ion cells or an inefficient battery management system. India does not manufacture its own lithium ion cell–a key component in a lithium ion battery, and companies source it from suppliers in South Korea, Taiwan, China and Japan. Ola sources its cells from LG Chem in Korea.
There are different types of battery chemistries available in the market with two prominent ones for EVs–NMC and LFP. NMC is more dense in energy as compared to LFP but is considered relatively less stable. LFP batteries have a significantly higher thermal runaway threshold of 270 degrees celsius against NMC’s 150 degrees. Ola uses a high voltage 48Volt 3.97 kilowatt hour NMC battery.
This is not the first such instance of an electric scooter catching fire in India. In September last year, two scooters from Pure EV also caught fire followed by another from Okinawa in October. In December, another scooter from Manesar based HCD India caught fire while being charged leading to the tragic death of a 60 year old man. Yet, this is one of the most high profile cases given Ola’s stature in the market as the best funded startup in the industry, which is at the forefront trying to revolutionize the EV market in India.
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“This is utterly shocking. We had heard reports that Ola was rushing through some protocols in product development but we never thought they would be negligent in batteries,” said an industry insider. “This can be very damaging for the industry as a whole. Ola would need to answer a lot of things.”
The Ola electric story in India has been a roller coaster ride in itself and not everything has gone as per plan. To begin with, the company struggled with ramping up capacities at its mega 10 million unit futurefactory in Tamil Nadu. As a result, deliveries to customers were delayed for months. The first batch of customers also got the scooter without some of the promised features like hill-hold and cruise control functions and voice command.
In February this year, one customer Malay Mohapatra also suffered from a bizarre malfunction when his scooter went into reverse mode and accelerated at 102 kph.
As the battery is the heart of any electric vehicle, its safety is one of the key issues that the industry is facing not only in India but across the world. There has been a gradual increase in the number of fire incidents commensurate with the rise in sales across the globe. Last year General Motors expanded the recall exercise for its Bolt EVs by 73,000 vehicles to now include every Bolt ever manufactured, at a cost of nearly $ 2 billion. Similarly South Korean auto giant Hyundai recalled 82,000 EVs after 13 incidents of fire were reported in its compact crossover Kona electric. This includes 456 units of the car that it sold in India.
With a significantly lower number of moving parts, EVs are relatively simpler to produce. The battery however, is complex and the vehicle’s overall safety depends on the efficiency of the battery management system–how well the battery is cooled and how good the insulation of the pack is from outside elements. India does not produce lithium ion cells of its own which invariably is imported mostly from China. Industry sources say that is where most of the grey areas exist.
Low entry barrier, the promise of high growth and a ready made sourcing destination in China–world’s largest electric vehicle market, has led to scores of companies mushrooming almost overnight. With the traditional players not fully committed to the EV story, the field is wide open for newer players to emerge. Not everybody is a long term player and the fear is non serious players cutting corners to end up giving the overall industry a bad name.
Why do batteries catch fire?
It is important to understand here why lithium ion batteries catch fire. Today, Li-ion batteries are all around us in smartphones and laptops, power banks and tablets, but the ones used in EVs are fundamentally different from the rest. For one, EV batteries store up to three times more energy than laptops or any other household appliance. The abuse they have to endure is also vastly different and include exposure to wide temperature extremes, dust and humidity, vibration due to terrain, water, high rates of charge and discharge.
To increase a vehicle’s driving range, it requires high voltage, which in turn means long strings of cells and high energy storage. Batteries with flammable electrolytes are particularly vulnerable where vehicles may be charged in confined garage spaces of private residences and commercial businesses.
Typically batteries contain both an oxidizer (cathode) and fuel (anode as well as electrolyte) in a sealed container. Combining fuel and oxidizer is rarely done due to the potential of explosion hence the state of charge (SOC) is an important variable. Lower SOCs reduce the potential of the cathode oxidizing and the anode reducing. Under normal operation, the fuel and oxidizer convert the stored energy electrochemically (i.e., chemical to electrical energy conversion with minimal heat and negligible gas production). However, if electrode materials somehow start reacting chemically in an electrochemical cell, the fuel and oxidizer convert the chemical energy directly into heat and gas. This is the beginning of a fire hazard situation. Once started, this chemical reaction will likely proceed to completion because of the intimate contact of fuel and oxidizer, becoming a thermal runaway. Once thermal runaway has begun, the ability to quench or stop it is difficult. As much as anywhere else, prevention is the best cure here.
What complicates this potentially combustible mix is the use of new electrode materials to answer the needs of even higher energy content and higher voltage operation. Electrode materials represent some of the most reactive materials known and have a profound influence on the safety and abuse tolerance of the cell and battery pack. The choice of cathode is of particular significance. The material of choice today has lithium alongwith one or a bunch of other materials like cobalt, nickel, manganese or aluminum. Each has different characteristics depending on the type and ratio of the metals–Ni(Nickel) has high capacity, manganese and cobalt have high safety and aluminum increases the power of a battery.
The emergence of lithium iron phosphate (LFP) is relevant. They are cheaper, do not use nickel or cobalt and are more stable and safer. On the flip side, they are relatively less dense in energy so manufacturers looking for higher range and performance still tend to opt for NMC batteries. Ola does too.
