The London Fire Brigade has stated that the fastest-growing risk in the capital is [lithium battery-powered] e-bikes and e-scooters. As reported by the BBC, there was a 78% increase in e-bike fires in 2023 compared to the previous year, with 155 e-bike fires and 28 e-scooter fires recorded.
It’s not just powered transporters that carry such risks. Fires are reported multiple times a year, sparking concern around the proper use, storage, and disposal of lithium batteries. Examples include a storage unit blaze in Surrey last year and frequently reported bin lorry fires.
Multiple risk factors
Lithium-ion batteries are favoured for their high energy density and long life. However, these very characteristics also make them prone to overheating and thermal runaway—a condition where the battery’s temperature increases uncontrollably, potentially leading to fires or explosions. The materials within these batteries are highly flammable and reactive, exacerbating the risk when damaged, overcharged, or manufactured poorly.
Several scenarios can lead to lithium battery fires, including:
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Overcharging: This increases the battery voltage beyond safe limits, generating excessive heat.
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Physical Damage: Batteries that are dropped, pierced, or struck can suffer internal damage, leading to short circuits.
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Electrical Short-circuiting: Often caused by manufacturing defects or damage, short circuits can rapidly produce heat and ignite the battery.
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Improper Storage: Storing batteries in hot or poorly ventilated areas heightens the risk of thermal runaway.
Battery Management Systems (BMS): A well-set-up BMS is essential. It keeps track of the battery’s health, including its charge, temperature, and whether all parts work well.
The warning signs your e-bike or e-bike battery is a fire hazard
- Heat: It’s normal for batteries to generate some heat when charging or in use. However if your device’s battery feels extremely hot to the touch, there’s chance it’s defective and may start a fire
- Bulging: A battery bulging or swelling out of shape is a common sign of it failing. If your battery looks swollen, you should stop using it immediately. Similar signs include any type of lump or leaking from the device
- Noise: Failing lithium batteries have also been reported to make hissing or cracking sounds
- Smell: If you notice a strong or unusual smell coming from the battery, this could also be a sign of it failing
- Performance: A failure to fully charge or longer charge times can be a sign that your battery is failing
- Smoke: If your battery or device is smoking, a fire has already started
Disposing of a lithium battery
Lithium batteries should not be placed in the same bins as your regular rubbish or recycling. If they overheat, they may cause it to catch fire. Instead check your local authority’s website for the safe way to dispose of lithium batteries in your area.
Procedures for Handling Lithium-Ion Battery Fires
Fires involving lithium-ion batteries are complex because they can include electrical parts and flammable liquids and gases. These fires don’t fall into just one category; they cover several, including class A, B, and C fires. When a lithium-ion battery catches fire, only people who are trained to deal with these emergencies should handle it. They must look at the situation closely and choose the safest way to respond, considering how intense and advanced the fire is.
Key steps are to lower the oxygen around the fire and cover the flames to weaken them. Cooling the area with water helps stop the fire from spreading. It’s crucial to control the situation so the fire in the original battery cell can slowly go out under safe conditions.
Fire Risk Assessment
Regularly check stored batteries for signs of damage, such as swelling, leaks, or changes in shape. If a battery is damaged, dispose of it right away to avoid the risk of a fire. Make sure that fire suppression and handling equipment is available near where you store batteries. Also, staff should be trained on what to do in case of emergencies involving lithium-ion batteries.