The voltage capacity in a power bank is too low to cause death, but a surge caused by a short circuit can cause a person’s heart to stop.
This statement by Universiti Teknologi Malaysia Professor Dr Jasrul Jamani Jamian, from the university’s Electrical Enginering Faculty, came after a 19-year-old Melaka boy was found dead last week after he had fallen asleep with his earphones on, which was plugged into his mobile phone that was charging.
The professor said it was safer to charge mobile phones using power banks than electrical sockets.
This, he said, was due to the limited power supply in power banks as opposed to the continuous electricity flow from wall sockets.
Dr Jasrul said the death of the teen recently could occur only if there was electric current flowing to the heart caused by a short circuit in the power bank.
“Many people think that a low voltage such as 12 volts could not possibly kill someone However, a short circuit from a 12-volt source can produce a high current and death can occur when this current flows through the heart,” Dr Jasrul said.
“For example, an average value of 2.1 ampere output current is normal for power banks, but a short circuit current in power banks can exceed 100 amperes. It takes only 0.5 amperes of electrical direct current to the heart to cause death.
“Thermal runaway occurs in a very short time and when in contact with the body, it can cause burns to the skin and more severe consequences,” he told the New Straits Times.
Dr Jasrul said people were not encouraged to put mobile phones or power banks close to their body when charging their phones at night.
“This is important to avoid injury due to short circuit in power banks.
“Consumers also need to know the quality of power banks or phones that they buy as some items (can be) fake and have no short-circuit protection.”
He added that it was unlikely that earphones would transmit electricity to the body.
The victim had his earphones on. The earphones were connected to a mobile phone that was connected to a power bank.
The boy’s body had been found by his mother, 48, who went to wake him up at 7am. The mother used a duplicate key to open her son’s bedroom door and found him motionless on his bed.
He had burn injuries on his left shoulder near where the power bank was placed.
Federation of Malaysian Consumers Associations president Dr Marimuthu Nadason urged consumers to practise caution when using mobile phones.
Mr Mohamad Isa Md Saleh, a mobile phone trader at Melaka Sentral, said he advised his customers not to charge their mobile phones and power banks overnight.
“Overcharging can cause a short circuit in the long term,” he said, adding that one of his customer’s power bank exploded while being charged.
The customer, he said, had bought the power bank online and when he and the customer examined the exploded device, they discovered that it had no short-circuit protection.
In Melaka, police said further investigations were needed before the teen’s cause of death could be determined.
State Criminal Investigation Department chief Assistant Commissioner Kamaluddin Kassim said: “We have submitted the results to the Chemistry Department, and we are waiting for the results to determine his cause of death.
“It could be due to electrocution or cardiac arrest,” he said, adding that police had ruled out foul play. He added that neither the mobile phone nor the power bank had exploded.
The story of the teen’s death has gone viral, with netizens alarmed that such a thing could happen.