14-05-2025
Urgent warning over dangerous e-bike battery linked to fires and explosions that is still on sale across the country
If you own an electric bike, you need to check its battery right now, safety experts say.
An investigation by Electrical Safety First has found that dangerous e-bike batteries are being posted for sale via Facebook Marketplace across the UK.
Due to a defect with certain models, battery cells inside can reach temperatures of 1112°F (600°C) or more and spark a catastrophic fire.
Listings of these dangerous battery models were found to be advertised for sale in London, Manchester, Hull, Derbyshire, Southampton, Reading and more.
'We urgently need sellers to check if they are unknowingly passing on a dangerous e-bike battery,' said Giuseppe Capanna, product safety engineer at Electrical Safety First.
'A single unit of this affected battery being sold online could put a household at serious risk.'
So do you have one of the dangerous batteries in your e-bike?
Here's how to check.
According to the safety charity, the warning applies to two models of triangle-shaped e-bike batteries that are branded UPP (unit pack power).
The affected model numbers – which can be found on a label attached to the edge of the battery – are U004 or U004-1.
'If you have one of these batteries, it's important that you stop using it immediately,' said Capanna.
'These two batteries have been subject to a withdrawal notice, which means they do not meet The General Product Safety Regulations 2005.'
Thee models pose a serious risk of fire and can undergo a devastating process called 'thermal runaway' where the battery cells inside reach up to 1112°F (600°C), releases toxic gases and creates a ferocious fire that is almost impossible to extinguish.
It's thought the offending models have an insufficient battery management system to prevent the battery entering thermal runaway.
Already, fires across the country have been reported involving a UPP battery.
In March, a home in Surrey was damaged after a converted bike caught fire while on charge, linked to an unknown model of UPP battery.
The likes of Amazon and eBay have been notified about the faulty models but experts are worried they've been sold on Facebook Marketplace
How to identify a faulty e-bike battery
Consumers are being urged to check a black sticker that is often found on one of the outer sides of the triangular battery case displaying the model number of the battery.
If the corresponding model number U004 or U004-1 number is displayed on the sticker consumers are urged to stop using the battery immediately.
Government advice suggests those with the battery dispose of it safely by first checking with their local collection sites to ensure they cater for battery disposal.
And in September 2023, a high-rise property in Coventry was devastated when a fire linked to a U004 model battery spread quickly.
This incident in Coventry lead to a government withdrawal notice, published online in January 2024, which saw the battery removed for sale via various online distributors.
The withdrawal notice was issued to Amazon, eBay and Chinese e-commerce site Alibaba, stating that the UPP battery posed a serious risk of fire.
However, private listings of the battery were still being sold online on Facebook Marketplace, by private sellers in London, Manchester, Hull, Reading, Southampton and more.
Meta, the company which owns Facebook, confirmed it had removed the listings as a precaution after Electrical Safety First raised its findings.
But the experts are concerned that batteries already purchased are waiting to cause a catastrophe in buyers' homes.
Electrical Safety First has been able to identify seven private listings of the UPP battery with model numbers of either U004 or U004-1.
Worryingly, one battery for sale was described by the seller as being 'a little bit burnt' from being 'left near a radiator'.
Serious concerns were raised about another 13 listings where an identical shaped triangular UPP branded battery was visible but where the model numbers were unable to be confirmed, due to a limited number of photos used in the product ad.
These listings were also removed by Meta after being contacted by Electrical Safety First, but more soon followed.
In a follow-up investigation, the charity found a further six listings of the battery for sale online where the charity was able to identify the model number, matching that of the Government warning (again these were removed by Meta).
The findings comes as the Government's Product Regulation & Metrology Bill progresses through the House of Commons which seeks to address e-bike fires.
Electrical Safety First is calling for new laws to prevent substandard batteries coming onto the market and being available online.
'The current rules governing online marketplaces are not fit for purpose, and new laws are urgently needed to protect shoppers from dangerous goods being sold on these platforms,' Capanna added.
'Whilst we're encouraged that the Bill will address e-bike fires, it's essential it tackles the issue head on,' Capanna added.
'Online marketplaces need to be legally responsible for ensuring they take steps to prevent dangerous goods being available on their sites.
'We also need tougher safety laws to ensure poor quality, e-bike batteries posing a fire risk don't enter the UK market.'
'That's why we're urging the Government to introduce new laws that will mandate that e-bike batteries must be independently certified as safe before being sold in the UK.
'At present, manufacturers can self-declare their batteries are safe – we want this to end.
'The fight against substandard batteries is not one we can afford to lose.'
How does an e-bike work?
Electric bikes have a motor and battery mounted on the frame, with a display attached to the handlebars to let you control how much assistance you want.
So, as you're cycling along (you have to pedal to make the motor work) you can choose to increase the amount of power when you need it. Going up a steep hill, for example, or if you're tired towards the end of a journey.
E-bikes can help you reach speeds of 15.5mph, although if you pedal faster, you can go faster.
When the battery is low, simply remove it and connect to the mains to recharge it - times for this vary from three to six hours.
