Person burned as DIY e-bike home conversion kit explodes in Cambridgeshire’s sixth battery fire of the year

Firefighters have issued a warning to householders after being called to the sixth blaze this year in Cambridgeshire caused by charging batteries.

One person needed treatment for burns in the house fire in Wisbech early on Tuesday morning (15 April), which was caused after a battery from a DIY home conversion e-bike kit exploded, spreading throughout the home and causing significant damage.

It follows a ground-floor house fire in Green Park, Chesterton, attended by a Cambridge crew earlier this month, which started when a battery exploded in the living room. An e-scooter, power tools and other items had all been on charge. The damage was only limited because the residents closed the doors while evacuating.

Over-charging batteries can lead to a process called thermal runway - uncontrollable self-heating due to a chain reaction involving the lithium-ion within them.

At the end of March, crews from Ely, Burwell and Newmarket attended a kitchen fire at a Soham home, where a games console controller and a portable power bank were charging.

Days later, in Orton Malborne in Peterborough, a battery in another DIY home conversion e-bike kit, bought via an online marketplace, exploded and a resident suffered sustained burns that required hospital treatment. These fires also badly damaged the homes.

Station commander Gareth Boyd, one of Cambridgeshire Fire and Rescue Service’s community risk managers, said: “These incidents highlight the potential risks that lithium-ion batteries can pose and how it is vital for people to be alert when charging any kind of device. Last year firefighters attended around 20 fires involving batteries charging in homes, with more occurring already in 2025.

“Electrical devices are a key part to everyday life for most people. Mobile phones, tablets, laptops and games console controllers, as well as vehicles like e-bikes and scooters are used daily and need to be powered to do so.

“Most devices come with safety features to ensure they do not overheat when being charged. Using the charging packs, cables and plugs provided by the manufacturers, rather than cheaper versions will help charge devices safely. Replica replacement chargers sometimes don’t have these features and can end up overcharging the battery, which causes thermal runaway leading to explosions and rapidly intense fires.

“We have seen items for sale, at car boot sales as well as online, that people can use to covert a standard bike into an e-bike. These whilst seemingly a cheap alternative can be highly dangerous and do not conform to the required standards to be sold in the UK.”

Residents are urged to ‘Take Charge and Be Safe’, following some simple tips.

Gareth added: “Most new items come with a suitable battery and charger. However, if you are looking to purchase additional ones then make sure they are the right voltage and are fully compatible. Other things like charging a mobile phone while you are awake and alert, rather than while sleeping, means the device won’t be overcharged and risk overheating the battery. This can be the same for any device.”

At bedtime, get into a routine of making sure all internal doors are closed, electrical sockets are switched off, any candles or heating appliances are off and hallways and stairs are clear of obstructions. These moves can help prevent a fire and aid an easy escape.

Gareth said: “Many fires in the home start at night while people are asleep. This can be down to a number of different causes, but can be easily avoided by following a few simple tips, as well as having working smoke alarms on each floor of your home.

“A bedtime routine is a great way to help you and your family stay fire safe in your home. By following a few simple tips before heading to bed for the night, you can prevent a fire from happening or, if one does break out, stop it from spreading."

An online home safety check is available also enables you to carry out a fire risk assessment of your home. The tool goes through each area of a property and generates a safety plan for the occupants to follow. It can also be carried out on behalf of a vulnerable family member.

More information about keeping your home and family fire safe can be found on Cambridgeshire Fire and Rescue Service's website: www.cambsfire.gov.uk.