EV Battery Fires: Understanding EV Battery Fires, Risks and Safety Measures

EV Battery Fires Latest News

• A devastating fire tore through a house in Indore recently, killing 8 people — including 2 children. 
• The blaze is suspected to have originated from an EV charging point located outside the house. An official investigation is currently underway.

Safety of EV Batteries

• Lithium-Ion Batteries: Common but Efficient – Most EVs use lithium-ion batteries, similar to those in smartphones and laptops. They offer high energy density and are generally safe when properly managed. 
• Role of Battery Management System (BMS) – EVs are equipped with a Battery Management System (BMS). It regulates temperature and ensures the battery operates within safe limits during charging and discharging.
• Risk of Thermal Runaway – A key risk is thermal runaway, where:
  • One battery cell overheats 
  • Heat spreads to nearby cells 
  • A chain reaction occurs, overwhelming the cooling system.
• Fire and Toxic Gas Risk – During thermal runaway, batteries release flammable and toxic gases such as hydrogen fluoride. These gases can intensify fire risk and make incidents more hazardous.
• Overall Insight – EV batteries are generally safe, but rare failures like thermal runaway can lead to serious fire hazards if not properly controlled.

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Causes of Thermal Runaway in EV Batteries

• Physical Damage to Battery Pack – Strong impacts (especially to the undercarriage) can damage the battery casing. This may puncture or deform cells, leading to internal short circuits and overheating. 
• Overcharging and Faulty Chargers – Charging beyond safe limits can cause charge buildup in unstable areas of the battery. Use of third-party or damaged chargers increases this risk. Repeated overnight charging with unsafe chargers can worsen the problem.
• Manufacturing Defects – Rare defects like metal protrusions inside cells can connect positive and negative electrodes. This leads to sudden high current flow, generating excessive heat and triggering thermal runaway.
• Electrical Infrastructure Issues – Weak or old wiring and extension cords may not handle sustained current. This can cause overheating during charging, indirectly increasing fire risk.

Impact of External Conditions on EV Battery Safety

• Heat and Thermal Stress – High temperatures, especially during Indian summers, can strain the cooling system. Parking in direct sunlight or charging immediately after long drives increases thermal stress on batteries.
• Battery Age and Maintenance – Over time, batteries degrade internally, increasing risk. Ignoring warning signs or skipping inspections may hide issues like swelling or chemical breakdown.
• Risk from Flooding – Floodwater can enter battery packs, causing short circuits. Several EV fires have been reported days after vehicles were submerged.
• EV vs Petrol Vehicle Fires – EVs are not uniquely dangerous—petrol vehicles catch fire more often. However, EV battery fires: 
  • Burn hotter and faster 
  • Are harder to extinguish due to oxygen release 
  • Firefighting requires large amounts of water or special equipment.
• Role of Surrounding Factors – Fire risks can increase due to external elements like: LPG cylinders stored nearby; Presence of other vehicles; Power failure affecting safety systems (e.g., electronic locks).

Industry and User Measures to Improve EV Battery Safety

• Advanced Cooling Technologies – EVs use coolant channels to absorb and dissipate heat.  New systems are being developed where coolant evaporates to improve heat transfer, helping manage sudden temperature spikes.
• Safer Battery Design Innovations – Shift towards solid-state batteries (using solid electrolytes) to reduce fire risks. Improved internal firewalls to prevent fire from spreading between cells if one fails

User-Level Safety Precautions

• Use only manufacturer-approved chargers.
• Avoid unattended or overnight charging with unsafe setups.
• Ensure home electrical systems can handle high loads.
• Get batteries checked after impacts.
• Allow battery to cool after long drives before charging and keep charging areas clear.

Strengthened Safety Standards in India

• Bureau of Indian Standards (BIS) updated EV battery safety norms in 2023. 
• Under AIS-156 standards, batteries must: 
  • Undergo tests for heat propagation 
  • Provide at least five minutes for passenger evacuation in case of fire

Source: TH