E-bike and e-scooter fires reached a record high last year, new figures suggest.
There were 432 blazes involving e-bikes during 2025 - a 38% jump compared with a year earlier.
Meanwhile, 147 e-scooter fires were reported, up 20% from the 123 seen in 2024.
These incidents are often caused by failing batteries, conversion kits and chargers.
Products bought from online marketplaces are at a greater risk of malfunctioning, because they aren't subject to the same regulation as established retailers.
Nick Bailey from BatteryIQ said the e-scooters and e-bikes involved in fires are "always cut-price products" manufactured with lax quality control.
He added: "There's also a growing black market in DIY and counterfeit batteries, particularly for delivery riders, built using battery cells reclaimed from disposable vapes.
"I wouldn't keep a battery in my home without continuous monitoring - regardless of what the manufacturer's sticker says."
The PA news agency sent Freedom of Information requests to all 49 fire brigades in the UK and asked for the number of incidents recorded between 2021 and 2025.
London Fire Brigade recorded the greatest number of fires by far, with Greater Manchester and Nottinghamshire identified as hotspots outside of the capital.
Fires involving lithium batteries used for e-bikes and e-scooters can spread rapidly and produce a toxic vapour.
Electrical Safety First has warned this issue is "swiftly becoming a runaway train that needs to be stopped" - with incidents surging over the past five years.
The charity's chief executive, Lesley Rudd, warned: "Poorly made batteries and accessories are of huge concern, and are a major route through which dangerous devices are entering people's homes.
"Without strong and enforceable changes, lives are at serious risk and further loss of life is, sadly, inevitable."
The London Fire Brigade's deputy commissioner, Spencer Sutcliff, has said he is "extremely concerned" about the "worrying amount" of cases in the capital.
E-scooters and e-bikes have now been banned from the Tube because of the fire risk they pose.
Although private e-scooters have been banned from being used in public areas nationwide, they are often ridden illegally in many urban areas.
Which? has warned unsafe products are "increasingly saturating" online marketplaces, which undercut responsible businesses that comply with the law.
The government launched a consultation last week that is designed to boost product safety in the UK.
Under the plans, online marketplaces would be legally required to "prevent, identify and remove dangerous products being sold via their platforms".
(c) Sky News 2026: E-bike and e-scooter fires have hit a record high - this is why
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