Cambridge fire chief warns of electric bike and scooter explosion risk

A fire station commander in Cambridge has warned of the risk of explosion and serious fires posed by charging electric bikes and scooters indoors overnight after two people were lucky to escape with their lives.

James Ball, station commander of Cambridge Fire Station, raised the alarm after witnessing the effects of a blaze in a flat in King’s Hedges, in which an e-scooter’s battery overheated and the sleeping owners only survived thanks to a smoke alarm.

He told the Cambridge Independent that electric vehicle battery fires were a growing threat and that people should never charge them while they were asleep in case a battery explodes and a blaze quickly escalates.

James said: “Without doubt there is a significant risk from these vehicles. I think the problem is going to get worse until the safety around the batteries is improved.

“I suspect we will go to more and more of these fires and it’s vitally important that if members of the public are using these types of vehicles that they do follow this safety information by making sure that they’ve got working smoke detectors or heat detectors, and only charging them while you’re present at the premises – and not leaving them on overnight or charging them at a property if you’re not there.

“If the batteries overheat, a process called thermal runaway starts to occur, which causes huge amounts of heat, mini explosions, and you get very quick and very rapid fire spread.”

Describing the e-scooter fire in the city, a spokesperson for Cambridgeshire Fire And Rescue Service said: “Crews from Cambridge attended a fire in the early hours of the morning on Tuesday, May 30. They arrived at Temple Court in King’s Hedges at around 4am to find a fire involving an electric scooter charging in a house. Wearing breathing apparatus they extinguished the fire using a hose reel and cleared the smoke using a positive pressure ventilation fan.

“The occupants of the house were able to escape without being injured, and were alerted to the fire thanks to a working smoke alarm.”

James explained: ”Had they not had smoke detectors, it would more than likely have ended up being fatal.

“It was a fairly new scooter. It had only been bought a couple of weeks previously, and they charged the scooter between the hours of 12 at night and seven in the morning, which is obviously when then their electric bill was cheaper.

“But that’s the worst one of the worst things that you can do because it’s been left unattended, and it’s while you’re asleep.”

The fire was so severe it melted through the scooter and caused significant damage to the home.

James issued the warning as more people are buying e-scooters and e-bikes without understanding the risks associated with their batteries.

He said: “When we got there, it was a fairly well developed fire. It was contained to the kitchen area and crews got there quite quickly and were able to remove the scooter and get it out.

“With lithium batteries, the fire is actually very difficult for us to extinguish because when it goes into this process of thermal runaway, it starts to produce his own oxygen. We have to submerge it in water and bring its critical temperature down.

“They also produce a lot flammable gases, so it is very, very toxic. The crews had to go in wearing breathing apparatus and drag it out into the garden before going back in and extinguishing the rest of the property.”

London Fire bridage has shared a video of an electric scooter exploding.

Station Commander James Ball offered a series of safety tips for owners of e-bikes and e-scooters:

Do not charge while you are sleeping.
Stop charging once the battery is full to avoid overheating.
Only use the correct charger that comes with the vehicle.
Have at least one smoke alarm.
Batteries can be damaged in vehicle crashes or by dropping them – they are more at risk of fire afterwards, so check for signs of damage and replace.
Recycle your batteries carefully. Do not place in household waste.
Only buy replacement chargers and batteries from reputable stores - many fires involve counterfeits.