Rechargeable lithium-ion batteries are now a ubiquitous feature of our lives and are found in a multitude of items from mobile phones and laptops to portable tools, e-bikes and scooters, mobility aids, and electric vehicles.
Lithium-ion batteries are generally safe when used correctly, however manufacturing defects, physical damage, overcharging and over discharging, or exposure to an external source of heat can create a condition where the battery cell generates more heat than it can dissipate which can lead to a rapid and uncontrolled release of heat energy, known as a ‘thermal runaway’. Thermal runaway can result in a range of flammable and toxic gases from the battery casings being emitted. The flammable gases generated often ignite immediately, but may also spread out unignited, until the encounter an external source of ignition, resulting in an explosion. Lithium-ion battery fires generate oxygen and can be very difficult to extinguish.
While the rate of lithium-ion battery fires is low the consequences can be substantial. According to the London Fire Brigade e-bikes and e-scooters have become London’s fastest growing fire risk. In 2023 there were a 183 e-bike and e-scooter fires in London, a 78% increase compared to 2022, three people tragically died in these fires and around 60 people were injured.
As our reliance and usage of lithium-ion batteries increases, has the potential fire safety risk and the precautions necessary to control it, been recognised in the fire risk assessment for your premises? For a fire risk assessment to be regarded as ‘suitable and sufficient’ then it must consider all significant fire risks present, including those presented by lithium-ion batteries (either through storage, use, or charging arrangements), and how these risks will be controlled.
While identifying how and when a lithium-ion battery could catch fire is unrealistic, The Fire Protection Association has published a checklist of practical, preventative measures to reduce the likelihood of fires occurring in the first place, which are:
- 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. These should be safely disposed of;
- Only charge batteries with the original charger supplied;
- Do not leave batteries charging in unoccupied locations and disconnect / remove batteries from chargers after 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, such as 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 in close proximity. While keeping these products close together does not increase the risk of a fire occurring, keeping these products away from each other can reduce the risk of fire spread from one battery / battery-powered-device to another;
- Remember to store batteries or products using lithium-ion batteries in a cool dry place away from flammable and combustible materials.
If you have any questions on any of the issues raised in the above article, please contact Gary Foggo.