Indore EV Tragedy - Why Do Electric Vehicle Batteries Catch Fire?

Why in News?

The recent electric vehicle (EV) fire incident in Indore has raised serious concerns about the safety of EV batteries in India.

Are EV batteries safe?

• Lithium ion Batteries – Most electric vehicles today rely on lithium-ion batteries, the same technology used in smartphones and laptops.
• These batteries offer:
  • High energy density.
  • Longer lifespan.
  • Better efficiency compared to traditional lead-acid batteries.
• Under normal conditions, EV batteries are safe due to the presence of a Battery Management System (BMS), which regulates temperature, voltage, and charging cycles.
• However, failures in this system or external factors can lead to dangerous situations.
• Thermal Runaway – A major cause of EV battery fires is a phenomenon known as thermal runaway.
• EV battery packs consist of thousands of tightly packed cells.
• During charging and discharging, these cells generate heat.
• If one cell overheats, it can trigger a chain reaction, causing adjacent cells to overheat.
• This cascading effect can overwhelm the cooling system and lead to:
  • Rapid temperature rise
  • Release of flammable and toxic gases (such as hydrogen fluoride)
  • Ignition and intense fire
• Thermal runaway is particularly dangerous because it spreads quickly and is difficult to control.

What are the factors triggering thermal runaway?

• Physical Damage – Battery packs are enclosed in reinforced steel or aluminium casings.
• However, Strong impacts (e.g., accidents or undercarriage hits), Deformation or puncturing of cells,can cause internal short circuits, leading to overheating.
• Overcharging and Faulty Charging Systems
• Charging beyond designed limits can destabilize battery chemistry.
• While manufacturers include safeguards, third-party or damaged chargers may bypass these protections.
• Poor wiring or overloading in older buildings can also increase fire risk.
• Manufacturing Defects – Rare defects such as microscopic metal protrusions inside cells can:
  • Bring positive and negative electrodes into contact.
  • Cause sudden high current flow.
  • Generate excessive heat.
• Environmental Conditions – External factors play a significant role, especially in India:
  • High ambient temperatures strain cooling systems.
  • Parking in direct sunlight increases battery temperature.
  • Charging immediately after long drives adds thermal stress.
• Flooding is another risk factor:
  • Contaminated water can infiltrate battery packs.
  • This may cause short circuits even days after submersion.
• Battery Ageing and Poor Maintenance – Over time, battery components degrade.
• Ignoring warning signs (like swelling or overheating) increases risk.
• Lack of periodic inspections can allow faults to go unnoticed.

Are EVs more dangerous than conventional vehicles?

• EV fires – They often attract attention, but they are not uniquely dangerous.
• Petrol and diesel vehicles also catch fire frequently due to flammable fuel and high engine temperatures.
• However, EV battery fires differ in key ways:
  • Burn at higher temperatures
  • Spread faster
  • Are harder to extinguish
• Unlike conventional fires, EV battery fires can sustain themselves by releasing oxygen internally, requiring:
  • Large quantities of water
  • Specialized fire suppression techniques
• Lessons from the Indore Incident – The severity of the Indore tragedy was exacerbated by multiple factors:
  • Presence of LPG cylinders in the building
  • A fuel-powered sports bike parked nearby
  • Failure of electronic door locks during a power outage
• This highlights that EV-related risks are often compounded by poor safety practices and infrastructure gaps, rather than battery failure alone.

What are the technological and industrial responses?

• Advanced Cooling Systems – Modern EVs use liquid cooling channels
• New research focuses on phase-change cooling, where coolant evaporates to absorb more heat
• Improved Battery Design – Development of solid-state batteries (using solid electrolytes instead of liquid)
• Reduced risk of leakage and thermal runaway
• Fire Containment Mechanisms – Internal firewalls to prevent propagation between cells
• Improved insulation and compartmentalization
• Testing and Certification – In India, the Bureau of Indian Standards (BIS) has strengthened safety norms.
• Updated guidelines introduced in 2023
• The AIS-156 standard (by Automotive Research Association of India) mandates:
  • Thermal propagation testing
  • Minimum 5-minute escape window for users in case of fire
• Role of Users in Ensuring Safety – User behavior plays a critical role in minimizing risks:
  • Use only manufacturer-approved chargers.
  • Avoid unattended overnight charging.
  • Ensure home electrical systems can handle high loads.
  • Allow battery to cool before charging after long drives.
  • Get batteries inspected after accidents or impacts.
  • Keep charging areas well-ventilated and free from flammable materials.

What lies ahead?

• Electric vehicles are a crucial component of India’s transition to sustainable mobility.
• While EV battery fires are rare, their consequences can be severe due to the nature of lithium-ion chemistry and thermal runaway.
• The Indore incident underscores the need for a holistic approach involving robust technology, stringent regulations, and responsible user behavior.
• Rather than undermining confidence in EVs, such incidents should serve as an opportunity to strengthen safety frameworks, improve public awareness, and accelerate innovation.
• With appropriate safeguards, EVs can remain a safe and sustainable alternative to conventional vehicles.
• As the country accelerates its transition towards clean mobility, understanding the causes of such incidents becomes crucial.
• While EVs are generally considered safe and environmentally friendly, rare but severe battery fires highlight technological and regulatory challenges that need to be addressed.

Reference

The Hindu| The Indore EV Incident