E-scooters and bikes may pose a fire risk – if you don’t follow these rules
Experts reveal what causes lithium-ion batteries to catch fire, and how to safely store, charge and use e-vehicles
ByVicky Parrott27 June 2022 • 12:45pm
Sales of e-Bikes and e-Scooters are on the rise, but concerns over fire safety with lithium-ion batteries is also growing CREDIT: Getty Images
We all use battery powered products every day: from your toothbrush to your phone, it’s a routine part of most modern lives, and we rarely experience any safety issues.
However, stories of electric devices catching fire while charging are still a concern, especially with an e-bike’s battery causing a fire to break out in a London flat recently. So far this year, the London Fire Brigade has attended 56 fires involving lithium-ion batteries, 32 of which were e-bikes and seven were e-scooters.
So, what is it that causes batteries to catch fire, and is it safe to leave electrical items on charge?
David Greenwood, Professor of Advanced Propulsion Systems at the University of Warwick, explained that “generally there’s one of two things that can cause a fire when charging: the charger unit itself can catch fire, or you can have a fault in the battery where the cells either overcharge or overheat.
With lithium-ion batteries that are commonly used today, that can result in the cell catching fire. There is a battery management system fitted to electric vehicles, and every rechargeable electric device, that normally prevents that from happening. It’s when there’s a problem with that, that you get a fire.”
While the chemistry in modern lithium-ion batteries does vary, the way in which the battery works is the same whether it’s in an EV or in an e-scooter, and it is always made up of a series of cells that contain a cathode, an anode, a liquid electrolyte and a separator.
Battery fires are caused when the battery system heats up too much, causing the separator layers inside to break down and allow an internal short circuit. This generates further heat, and takes the battery from being in a safe electrochemical reaction, to an exothermic chemical reaction, initiated using small quantities of oxygen within the battery structure.
Once the battery’s external structure is breached, it can access further oxygen from the environment, which can support the fire until all of the battery material is consumed. This is why battery fires can, infamously, burn for a very long time.
But, in most cases, modern battery equipment is very safe and is tested to an extremely rigorous standard; It’s those rechargeable products that aren’t subject to such stringent regulations that are proving to be the significant problem.
Martin Brown, safety consultant at automotive test and development centre, HORIBA MIRA, stated that “just ten years ago, if we had any damage to battery systems, they’d be very likely to catch fire. Nowadays there are so many safety systems that it’s quite difficult to start a fire in a lithium-ion battery.
The most important thing with e-bikes and e-scooters is to get your system from a reputable manufacturer, and always use the provided charging cable. There are many cheap systems that we’re getting from around the world, and it’s difficult to know if the product has gone through reputable safety systems.”
The London Fire Brigade echoed the same sentiment, stating that the e-bike and e-scooter fires it attends are “predominantly in ones which have been purchased from online marketplaces, and batteries which have been sourced on the internet that may not meet the correct safety standards.”
Regardless of where an e-scooter or e-bike might be sourced, the LFB advises that you store and charge them outside in a shed if possible. Or, if they must be charged inside then make sure that they are on a hard, flat surface and in close proximity to a smoke detector.
The issue of unregulated e-scooters and e-bikes is currently due to be addressed in the new Transport Bill, which will introduce a low-speed, zero-emission vehicle category that should allow light electric vehicles such as e-bikes and e-scooters to be fully regulated and legalised.
As Professor Greenwood of Warwick University states: “We don’t need a new battery technology, what we have is safe; we just need a good set of legislated standards to design against, and to define safety standards.”
Experts reveal what causes lithium-ion batteries to catch fire, and how to safely store, charge and use e-vehicles
ByVicky Parrott27 June 2022 • 12:45pm
Sales of e-Bikes and e-Scooters are on the rise, but concerns over fire safety with lithium-ion batteries is also growing CREDIT: Getty Images
We all use battery powered products every day: from your toothbrush to your phone, it’s a routine part of most modern lives, and we rarely experience any safety issues.
However, stories of electric devices catching fire while charging are still a concern, especially with an e-bike’s battery causing a fire to break out in a London flat recently. So far this year, the London Fire Brigade has attended 56 fires involving lithium-ion batteries, 32 of which were e-bikes and seven were e-scooters.
So, what is it that causes batteries to catch fire, and is it safe to leave electrical items on charge?
David Greenwood, Professor of Advanced Propulsion Systems at the University of Warwick, explained that “generally there’s one of two things that can cause a fire when charging: the charger unit itself can catch fire, or you can have a fault in the battery where the cells either overcharge or overheat.
With lithium-ion batteries that are commonly used today, that can result in the cell catching fire. There is a battery management system fitted to electric vehicles, and every rechargeable electric device, that normally prevents that from happening. It’s when there’s a problem with that, that you get a fire.”
While the chemistry in modern lithium-ion batteries does vary, the way in which the battery works is the same whether it’s in an EV or in an e-scooter, and it is always made up of a series of cells that contain a cathode, an anode, a liquid electrolyte and a separator.
Battery fires are caused when the battery system heats up too much, causing the separator layers inside to break down and allow an internal short circuit. This generates further heat, and takes the battery from being in a safe electrochemical reaction, to an exothermic chemical reaction, initiated using small quantities of oxygen within the battery structure.
Once the battery’s external structure is breached, it can access further oxygen from the environment, which can support the fire until all of the battery material is consumed. This is why battery fires can, infamously, burn for a very long time.
But, in most cases, modern battery equipment is very safe and is tested to an extremely rigorous standard; It’s those rechargeable products that aren’t subject to such stringent regulations that are proving to be the significant problem.
Martin Brown, safety consultant at automotive test and development centre, HORIBA MIRA, stated that “just ten years ago, if we had any damage to battery systems, they’d be very likely to catch fire. Nowadays there are so many safety systems that it’s quite difficult to start a fire in a lithium-ion battery.
The most important thing with e-bikes and e-scooters is to get your system from a reputable manufacturer, and always use the provided charging cable. There are many cheap systems that we’re getting from around the world, and it’s difficult to know if the product has gone through reputable safety systems.”
The London Fire Brigade echoed the same sentiment, stating that the e-bike and e-scooter fires it attends are “predominantly in ones which have been purchased from online marketplaces, and batteries which have been sourced on the internet that may not meet the correct safety standards.”
Regardless of where an e-scooter or e-bike might be sourced, the LFB advises that you store and charge them outside in a shed if possible. Or, if they must be charged inside then make sure that they are on a hard, flat surface and in close proximity to a smoke detector.
The issue of unregulated e-scooters and e-bikes is currently due to be addressed in the new Transport Bill, which will introduce a low-speed, zero-emission vehicle category that should allow light electric vehicles such as e-bikes and e-scooters to be fully regulated and legalised.
As Professor Greenwood of Warwick University states: “We don’t need a new battery technology, what we have is safe; we just need a good set of legislated standards to design against, and to define safety standards.”
