|The phone and Kishori Saha. Pictures by Amit Datta
Aug. 29: A mobile phone blew up while being charged in a south Calcutta house, the “chocolate bomb-like explosion” leaving a pregnant homemaker speechless and quaking in fear.
Kishori Saha’s Nokia 2100 was plugged in for 15 minutes at the Ganguly Bagan home when the battery exploded. The 25-year-old Kishori, who is five months pregnant, was not hurt but she was in such a state of shock that she had to be taken to hospital.
The battery — BLD-3 — does not belong to the BL-5C series that were at the centre of a storm earlier this month when some cells of the series were recalled on suspicion of overheating.
A Nokia spokesperson said the “Calcutta incident” was being investigated. “From initial findings, it seems that the consumer was using a phone which was last sold in 2004. Nokia takes consumer issues very seriously and promotes the use of genuine accessories in phones,” a company statement said.
The mobile had been bought from a shop in Durgapur two-and-a-half years ago, Kishori’s husband Suman said but could not recall details.
When the BL-5C advisory was issued, a Nokia spokesperson had told The Telegraph that handsets and batteries are widely sold in the grey market. Companies usually don’t accept responsibility if accessories are bought from the grey market and in the absence of vouchers.
The battery identification number (26 characters in the case of BL-5C and 18 digits on the one that exploded) can help tell between the real and the fake but not if even that is forged.
An option is to see whether the hologram on the battery changes colour when held against light. If the colour changes, it can be more or less assumed that the product is genuine.
Till Wednesday night, the Nokia website (www.nokia.com) did not have information on the explosion or its possible causes. The Nokia helplines (08030303838 from BSNL landlines and 30303838 for other phones) were busy.
Scientists who specialise in batteries said a short circuit between the anode and the cathode or the failure of a protection mechanism to prevent overcharging are two possibilities that may cause a battery to explode. But they cautioned that precise reasons could not be established without examining the battery.
“When the charging schedule is not adhered to and overcharging happens, a protection mechanism is expected to work and safeguard the battery. But if the protection mechanism fails, an explosion can occur,” said N.G. Renganathan at the Central Electrochemical Research Institute in Tamil Nadu.
Kishori’s husband Suman, a website designer, said he was in office when he heard about the explosion at 1pm. He rushed home to find that his wife had been taken to Baghajatin hospital by neighbours. She was discharged without being administered medicine.
Neighbour Mithu Barui said she heard a “chocolate bomb-like” explosion.
Kishori’s landlady Beena Saha said she put “some toothpaste” on her tenant’s cheeks because of a “burning sensation”. “I could feel that she was shaking and her teeth were chattering,” Beena said.