A video accessed by The Quint shows an electric scooter by manufacturer Pure EV going up in flames in north Chennai.
This is the fourth such incident in four days. On Monday, videos surfaced showing an Ola Electric S1 Pro scooter catching on fire in Pune and an Okinawa Autotech electric scooter catching fire in Trichy.
On Saturday, another Okinawa electric scooter burst into flames in Vellore killing a man and his 13-year-old daughter, ET Auto reported.
The central government is dispatching a team of independent experts to investigate the Ola and Okinawa incidents, CNBC-TV18 reported, quoting government sources.
Another scooter by Pure EV reportedly caught on fire in September. The company did not immediately respond to our request for comments.
Ola and Okinawa Fires
No injuries were reported when Ola Electric's top of the line S1 Pro went up in flames in Pune. Videos circulated on social media showed a blue scooter, parked by the roadside, spewing smoke and bursting into flames in a matter of seconds.
Ola said that it is investigating the incident to understand the root cause and will take "appropriate action". The Quint reached out to Ola with a list of queries about the incident, but we haven't received a response yet.
The Okinawa electric scooter catching on fire in Vellore and killing two, however, appears to be a case of user-negligence according to the local police and the manufacturer, ET Auto reports.
Police investigation reportedly suggested that the user plugged the charger in an old socket with a less-than-recommended voltage capacity, which may have caused a short circuit.
Why Does an EV Catch on Fire?
Most EVs use rechargeable lithium-ion batteries which can store a lot of energy in limited space. In vehicles, these batteries can be exposed to debris, humidity, high temperatures – during Indian summers, for example – which can cause wear and tear.
These battery cells typically have four components: two electrodes, a separator which prevents contact between the two, and an electrolyte which is often a flammable liquid. The electrodes are placed close to each other, which increases the chances of a short circuit.
“This flammable liquid could get into what’s called a thermal runaway situation where it just starts sort of boiling, and that results in a fire,” Eric Wachsman, Director of Maryland’s Energy Institute told CNBC.
Thermal runaway is a phenomenon in which one exothermal reaction (which releases heat) accelerates other reactions, snowballing into an uncontrollable and sudden increase in temperature.
Because of this, it is critical that EVs have robust battery management and cooling systems, and high quality components.
Batteries with Nickel, Manganese and Cobalt (NMC), used by Ola and several other manufacturers, have high energy density, which means automakers can increase the range of their vehicles without increasing battery weight.
However, some manufacturers, including Tesla, are switching to lithium iron phosphate (LFP) cells as these are cheaper and are thought to be safer than NMC cells.
(Inputs from CNBC and ET Auto)