Lithium ion batteries are lighter, stronger and more efficient than traditional lead acid batteries, making them a popular choice for mobile phones, tablets, laptops, e-scooters and e-bikes, even electric vehicles. However, they have a major disadvantage in that if these batteries catch fire, the fire can be very difficult to extinguish.
It should be noted that the frequency of fire from lithium batteries is actually very low, despite the amount of publicity recent fires have attracted. But the popularity of the product means that the number of fires is on the increase. E-bikes and e-scooters have become London’s fastest growing fire risk with a 78% increase in 2023 compared to 2022. 155 were e-bike fires with 28 e-scooter fires. 3 people sadly lost their lives whilst approximately 60 people were injured. Often this was down to the item being stored or charged in a hallway when the battery failed, thereby blocking the escape route.
Examples of Recent Fires Due to Lithium Batteries
1. On Friday 26 January 2024 London Fire Brigade were called to a fire at a hotel in Kensington. A guest had placed a battery pack outside his hotel room door after hearing it hissing in the room. 20 minutes later it ignited, quickly filling the corridor with smoke. Despite his efforts to smother the fire he was unable to do so due to its intensity. Firefighters were on the scene with 4 minutes and worked to put the fire out. In this instance there were no casualties and 80 people were safely evacuated from the building.
Assistant Commissioner Pugsley from London Fire Brigade said: “This was a lucky escape for the occupant who inadvertently compromised his own escape route as well as others by placing it where he did in the corridor. If a battery is showing signs of failing, such as if it’s too hot, leave it alone and raise the alarm. In this case, the occupant picked the battery up before later trying to put out the fire using extinguishers. You should never try and tackle a lithium battery fire. Instead get away and call 999.”
2. On Tuesday 30th April 2024 London Fire Brigade responded to a fire at a hospital located on Pond Street in Hampstead. Around 40 people were evacuated by hospital staff when a fire broke out on a day ward. 6 people were assessed for smoke damage. The cause of the fire is believed to most likely be due to the failure of a lithium battery in a rechargeable vape stored inside a rucksack.
Why do Lithium Batteries Catch Fire?
Lithium ion batteries combine a flammable electrolyte with significant stored energy. If physical damage or heat exposure (e.g. from an external source or due to overcharging) occur the battery may create more heat than it can effectively disperse which in turn can lead to a rapid uncontrolled release of heat energy, known as thermal runaway. This can result in a fire of explosion. Flammable and toxic gases are ejected from the battery casing. They can ignite immediately or spread out until an external ignition source is encountered, resulting in an explosion. Lithium ion batteries also create oxygen during thermal runaway which can make a resultant fire very difficult to control
How to Minimize Risk of a Fire
Due to the difficult nature of lithium-ion battery fires, it is recommended that you do whatever you can to minimize the risk of a lithium-ion battery fire occurring. The following are some of the preventive measures that can minimise the risk of a lithium battery fire:
Only use batteries purchased from a reputable manufacturer or supplier.
Protect batteries against being damaged and do not attempt to recharge lithium-ion batteries with any signs of damage. Safely dispose of any damaged batteries at a recycling centre that is equipped to deal with their disposal.
Only charge batteries with the original charger or genuine replacement if necessary.
Do not leave batteries charging in unoccupied locations and disconnect/remove batteries from chargers once charging is complete.
Avoid storing, using, or charging batteries at very high or very low temperatures and never cover chargers or charging devices. Don't leave any equipment that may contain lithium-ion batteries such as mobile phones in high temperature environments, e.g. in direct sunlight, or a hot vehicle.
Don’t overcharge your batteries as this is a potential case of thermal runaway.
Avoid keeping lithium-ion battery products near each other as this will reduce the risk of fire spreading to another device if one ignites.
Remember to store batteries or products using lithium-ion batteries in a cool dry place away from flammable and combustible materials.
How to Extinguish a Lithium Battery Fire
Because lithium battery fires create their own oxygen during thermal runaway they can be very difficult to deal with. Fire fighters have discovered in recent years that lithium ion battery fires are prone to reigniting due to the lithium salts in the battery which are self-oxidizing and therefore can’t be deprived of oxygen in the traditional manner.
Never use water to extinguish a lithium battery fire as it can react with the lithium generating hydrogen gas which is highly flammable and will make the fire worse.
2. Unplug the device from any power sources if it’s safe to do so and place the lithium ion battery in a safe, non-flammable area away from combustibles
If a suitable fire extinguisher isn’t available, use sand or baking soda to smother the fire.
If the fire is too large or you’re unsure about how to deal with it, evacuate the area and call the emergency services immediately.
Lithium batteries should only be cooled with water by professionally trained people under controlled conditions when the benefits of can outweigh the risks. Cooling the batteries can prevent thermal runaway and help bring the fire under control.
