Man charged battery packs from illegally modified PMD resulting in fire that caused mother’s death
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Madam Tay Choon Hwee died from smoke inhalation after a fire broke out in her apartment, at Block 456, Ang Mo Kio Ave 10, in 2021.
PHOTO: ST FILE
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SINGAPORE – The battery packs of the illegally modified personal mobility device (PMD) a man had just bought caught fire while they were charging in his home, leading to the death of his 49-year-old mother.
In a report dated July 25, 2023, State Coroner Adam Nakhoda ruled Madam Tay Choon Hwee’s death in 2021 a misadventure.
The incident happened on March 5, 2021, at a unit on the 11th storey of Block 456 Ang Mo Kio Avenue 10.
The cause of death was certified as smoke inhalation, according to the report.
According to the report, Madam Tay’s son – named in the report only as Mr Ching – had bought the illegally modified PMD from a Mr Muhammad Shahrul Abdul Razak on March 4, 2021, for $1,400.
Mr Shahrul, who had just bought the PMD, had advertised the device on Carousell after his wife said it was too big.
The report said Mr Shahrul claimed he told Mr Ching the PMD was not compliant with Land Transport Authority (LTA) regulations.
When the pair met, Mr Shahrul gave Mr Ching two 36-volt lithium-ion battery packs, but not a charger.
Mr Ching rode the PMD home, and struggled to fit it into the lift.
At home, he removed the PMD’s battery packs at about 2am on March 5 and used a charger he already had to charge them.
Mr Ching did not have any issues with the charger, which he had used to charge four other PMDs he had previously owned.
Said the report: “He noted that the voltage of the charger and the battery packs’ voltage was the same. However, as he was ‘afraid’ to charge the battery packs, he monitored the charging process for two hours.”
As he did not notice any issues, Mr Ching went to sleep, leaving the battery packs to continue charging.
Sleeping in the same room as his mother, he was awoken by her between 5am and 6am, after she heard what sounded like explosions outside.
They approached the bedroom door and heard loud sounds. When they opened the door, they saw a fire around the PMD in the living room and the lithium-ion battery cells were popping.
As Mr Ching went to the kitchen toilet to get water to extinguish the fire, he heard his mother saying she could not see and was returning to the bedroom to call for help on her phone.
Mr Ching saw thick black smoke entering and filling the kitchen area. As it was affecting his breathing, he closed the toilet door, opened the window and shouted for help.
A member of the public called the Singapore Civil Defence Force (SCDF), whose officers used a compressed air foam backpack and a jet hose to extinguish the blaze.
One of the officers noted the living room was full of hoarded items.
Mr Ching was found in the kitchen toilet and told officers his mother was in the bedroom.
An SCDF officer found Madam Tay lying unconscious on the floor with some items on top of her.
After paramedics performed cardiopulmonary resuscitation on her outside the unit, she was rushed to Tan Tock Seng Hospital (TTSH), where she was pronounced dead at about 8am.
Mr Ching did not appear hurt and was also taken to TTSH.
The State Coroner noted that the modified PMD was not certified for use in Singapore.
He said the original battery pack had been removed, and the device was powered by two external battery packs.
He added that the 72-volt charger may have been incompatible with the two 36-volt battery packs, and it was possible they may have been overcharged, leading to the fire.
He said: “This case, as with several recent cases, is a timely reminder of the inherent dangers posed by modified PMDs. It would be advisable that users do not purchase PMDs that have been modified and do not undertake modifications to stock PMDs that they have purchased.
“The only PMDs that should be purchased and used should be ones that are UL-2272 certified and LTA-registered. Users should also only charge the PMDs using chargers that were supplied with the PMD.”

