E-Bike Battery Fires UK: Half Now Start When Not Charging

E-Bikes · Analysis

Just over half the e-bike and e-scooter fires reported to the government’s product safety office in 2025 started when the battery wasn’t charging. The advice never to charge overnight still matters. It covers about half the problem.

Nearly every e-bike fire warning says the same thing. Don’t charge it overnight, don’t charge it in the hallway, unplug it when it’s full. That advice is sound. Two of this autumn’s worst fires, in Bootle and in Bow, both involved a battery on charge.

But the government’s latest fire figures, published on 30 September, show something the warnings mostly skip. Last year, more of the reported fires started when the battery wasn’t plugged in than when it was.

The Office for Product Safety and Standards (OPSS) collects reports of e-bike and e-scooter fires from fire services across the UK. We took its data tables for 2017 to 2025 and tracked how the picture has moved since it relaunched the reporting system in 2023. Below: where fires now start, which bikes burn on the charger, and what that means for where you keep yours.

More than half of fires now start off the charger

OPSS records whether the battery was charging when the fire started. In a third of 2025 cases nobody could tell. Leave those out and the split is 86 fires on charge and 93 not charging. That’s 52%.

In 2023, the first year after the reporting system was relaunched, the figure was 41%. It passed half in 2024 and stayed there.

A fire that starts off the charger isn’t a mystery. London Fire Brigade says batteries fail when they’re badly built, fake or damaged, as well as when they’re overcharged or used with the wrong charger. Only the last two need a plug in the wall.

More than four in ten fires now start outdoors

The second shift is where fires begin. In 2025, 100 of the 222 fires with a known starting point began outside: 47 in a road or street, 31 in a garden or courtyard, 14 in a park and 8 on balconies or outside structures. That’s 45%, up from 34% in 2023.

The data doesn’t record why. More bikes being ridden and parked outside every day is the obvious candidate, but these figures can’t prove it.

Indoor fires haven’t gone away. Bedrooms, living rooms and hallways still accounted for 73 fires between them, and those are the ones that trap people. Merseyside Fire and Rescue Service’s own count of lithium-ion battery fires points the same way as the national data: of 150 since April 2023, it says almost half were in the home.

“This incident highlights why you should always ensure your escape route is clear and why we recommend never storing an e-bike or e-scooter on your means of escape, such as a hallway or by your front door.”Richard Field, Deputy Assistant Commissioner, London Fire Brigade, after a fire in Bow, September 2026

Home conversions are the bikes that burn on the charger

Split the figures by type of bike and the pattern changes. We pooled 2023 to 2025 to get bigger numbers. Of 192 conversion fires with a known charging status, 120 started on charge: 63%. Unlike factory-built pedelecs meeting strict UK EAPC e-bike laws, DIY conversions frequently bypass standard motor cutoffs and thermal protections. For factory-built e-bikes it was 35 of 83, or 42%.

Conversions are also a big slice of the total. In 2025, 82 of the 119 e-bike fires where the build was known involved a converted bike: 69%. That doesn’t prove a conversion is riskier than a factory bike, because nobody counts how many of each are on the road. It does show where fire services keep finding the problem.

“The biggest problem that we’re seeing is sub-standard versions of these batteries, quite often bought from third-party sellers on online market places. (If you are considering an extra power pack, read our guide on whether you should buy a second e-bike battery before purchasing).”Giuseppe Capanna, Electrical Safety First, speaking to BBC Radio 5 Live, September 2026

Cheap batteries turn up in more places than the conversion kit market. We’ve shown why the £79.90 e-bikes advertised on TikTok can’t contain the battery they claim.

From our own experience in Sheffield repairing and servicing e-bikes: the vast majority of dangerous battery failures we see come from unbranded conversion kits bought off marketplace platforms. They’re often paired with mismatched 54.6V chargers that lack thermal cutoff protections, wrapped in generic heat shrink without proper cell spacing.

More people hurt, fewer killed

Reported injuries rose to 98 in 2025, the highest in the series. Reported deaths fell from 10 in 2023 to 2. OPSS says both counts only include cases fire services told it about, so the real figures may be higher.

The London column explains why we compare shares rather than totals. London Fire Brigade sent 99% of reports in 2021 and 80% in 2025, as more fire services joined in. Some of the rise in fires is better reporting, not more fires. London’s own count tells a similar story: the Brigade attended a record 206 e-bike and e-scooter fires in 2025.

2026 has already been worse for deaths. In Bootle on 22 September, a mother and three of her children died in a fire where investigators found an e-scooter battery on charge.

“They can enter a process that’s known as thermal runaway and that’s basically where the battery will really rapidly overheat and it’ll create a really nasty intense fire. They can spread very, very quickly.”Becky Guy, Senior Policy Manager, RoSPA, to BBC North West Tonight, September 2026

Store it as carefully as you charge it

None of this makes the charging advice wrong. A third of reported fires still started on charge, and conversions mostly burn there. The data just says storage, damage and where the bike lives between rides matter about as much.