The London Fire Brigade (LFB) has revealed that almost 40 per cent of e-bike fires are caused by conversion kits.
The news follows the publication of Electrical Safety First's Battery breakdown report, in which the organisation called for a ban on universal chargers for e-bike and e-scooters, stating they could increase the likelihood of catastrophic lithium-ion battery fires.
The charity warned that there is an increasing amount of people using chargers that are not compatible with the voltage of their e-bikes, which could prompt a self-heating chemical reaction called thermal runway.
This year there have been three deaths in London from battery fires. Moreover, in 2023 alone, LFB recorded 93 e-bike and 18 e-scooter fires – averaging one every two days.
"It's approaching about 40 per cent of fires [that] have been down to conversion kits," said Charlie Pugsley, assistant commissioner at the LFB. "If you don't have it fitted safely, then it's not a safe product – particularly if you don't use the right charger for it."
Electrical Safety First conducted a survey of 1,000 e-bike and e-scooter owners across the UK and found that 43 per cent of those polled used a secondary after-market charger to charge their e-bike or e-scooter.
Out of those, over one in three (38 per cent) said that their charger is not compatible with the voltage of the battery, while one in five (20 per cent) don't know.
Moreover, 44 per cent of poll participants admitted charging their device in a communal area of the property they live in, such as a hallway or staircase, and more than one in 10 (14 per cent) said they charge it in their bedroom.
"Incorrectly charging your e-bike or e-scooter battery comes at a dangerous cost," Pugsley added.
"Due to the large amount of energy stored in these batteries, the risk of fire is significantly higher if the battery becomes unstable," said Giuseppe Capanna, product safety engineer at Electrical Safety First.
"It's essential that you use a compatible charger, ideally the one that came with the device, and never block any exit ways when charging – the results could be fatal."
The charity recommends charging your device away from any vital exit ways to allow for a safe escape in the event of a fire. It is also recommending that manufacturers add clearer markings on the outlets of batteries to specify what voltage a charger should be.
The report included an account from Scott Angus. He was forced to jump from the second-floor window with his partner and dog after a neighbour's e-bike burst into flames in the communal hallway of a converted Victorian house, blocking their escape route.
"I was woken up around 1am to the strong smell of carbon," Angus recalled. "I opened the door and all I could see was a wall of thick black smoke. If that smoke had got inside our flat any sooner, I probably wouldn't be here."
Currently, government requirements stipulate that electrically assisted pedal cycles (EAPCs) must show the power output and the battery's voltage, and have a maximum power output of 250 watts. However, there are no specific regulations for conversion kits.
A spokesperson for the Department for Business and Trade said: "We are consulting on modernising our product safety framework to hold online marketplaces to account, ensuring items sold online meet the same standards as on the high street.
"If businesses don't comply with product safety regulations, the Office for Product Safety and Standards will take appropriate enforcement action such as ordering the removal of the product from the market."
Earlier this summer, Electrical Safety First said batteries for e-bikes and e-scooters should be regulated like fireworks and heavy machinery to better ensure their safety, as was done in New York City in March 2023 following a spate of fatal fires.
In July 2022, a huge fire in a London high-rise prompted firefighters to issue an urgent warning about the risk of fires involving the lithium batteries of converted e-bikes. Last year, there were more than 100 fires in the capital involving lithium-ion batteries, the fire brigade said.
