A Chennai-bound IndiGo flight was forced to make an emergency landing at Hyderabad’s Rajiv Gandhi International Airport on Sunday after a passenger’s power bank caught fire mid-air. The cabin filled with smoke and the crew extinguished the fire, and authorities have launched an investigation.

The scare is not the first of its kind. In May, a similar power bank fire occurred after touchdown aboard a Chandigarh-bound IndiGo flight, when a passenger’s power bank exploded and triggered an emergency evacuation. The device was reportedly tucked into a seat pocket when it combusted, prompting the passenger to alert the cabin crew.

Why power banks catch fire

Power banks typically contain multiple lithium cobalt oxide or lithium-ion battery cells, many of which may be low-quality, poorly manufactured or even recycled. Experts say these batteries are highly energy-dense and therefore vulnerable to overheating and combustion under certain conditions, and manufacturing defects in substituted low-quality or counterfeit cells are among the most probable causes of such fires.

According to IIT Bombay professor Sagar Mitra, a slight jolt during landing may cause a mechanical vibration, and combined with a fully charged battery, this could trigger an internal short circuit leading to fire. Internal leakages between a battery’s positive and negative terminals, electrolytic discharge caused by physical damage or degradation over time, and poor internal coating can also trigger such incidents.

Certain user habits can further increase the risk. Many people unknowingly expose their power banks to higher temperatures, overcharge them or keep using damaged devices, making them unsafe, said Vivek Panchal, managing director of battery manufacturer Powertron. Experts recommend keeping the state of charge at 80 per cent and avoiding charging to maximum capacity.

What the rules say

Most airlines in India, including IndiGo, SpiceJet and Air India, prohibit passengers from carrying power banks in checked-in baggage, though such devices are generally permitted in cabin baggage under prescribed limits. Keeping them in the cabin ensures that crew members can immediately detect and contain any potential fire, whereas a battery fire in the cargo hold would be far more difficult to access.

In November 2025, the Directorate General of Civil Aviation issued a dangerous goods advisory prohibiting passengers from using or charging power banks during flights and barring passengers from storing them in overhead bins, citing concerns that inaccessible devices could delay emergency response. Airlines were directed to make in-flight announcements educating passengers about lithium battery risks.

What passengers should keep in mind

Apart from combustion risks, overheating is a major issue. Technicians say these devices should ideally be stored below 55 degrees Celsius, and most modern power banks have an inbuilt over-temperature cut-off operated through a battery management system. Experts advise prioritising battery life cycle, cell quality and warranty while purchasing, and say users should cease using any power bank that overheats during charging or discharge. Visible swelling, leakage, unusual odours or excessive heating are warning signs that the device may be unsafe and should be inspected or discarded immediately.