How to Control a Lithium-Ion Battery Fire
Lithium-ion batteries now power a great deal of daily life, from phones and laptops to e-bikes, e-scooters, electric vehicles and the large battery energy storage systems appearing on commercial sites. Fires involving them are infrequent, but when they do happen they are notoriously hard to put out, which is why the question of how to control a lithium-ion battery fire is worth answering carefully. The honest starting point is that, for most people in most situations, the right response is not to fight the fire at all, and understanding why explains everything else about how these fires are managed.
Why these fires are so difficult to control
The problem begins with a process called thermal runaway, in which a battery cell generates more heat than it can shed, sending it into a self-sustaining reaction. As it runs away, the cell breaks down its own flammable electrolyte into a mixture of flammable and toxic gases, including hydrogen, carbon monoxide and acutely toxic hydrogen fluoride, while also releasing some oxygen of its own. That last point is the crux of the difficulty, because a fire that produces part of its own oxygen cannot simply be smothered in the way many other fires can. The reaction can be triggered by physical damage, exposure to external heat, a manufacturing defect, or overcharging, and it can lead to a rapid fire or, where vented gases gather before igniting, an explosion.
A further complication is that a lithium-ion fire that appears to be out can reignite hours later, as heat continues to move through the cells, which is why simply knocking down the flames is never the end of the matter.
What actually brings them under control
Because the burning cells make their own oxygen, control is achieved mainly by cooling rather than smothering. The fire and rescue service typically uses large quantities of water to draw heat out of the cells, lowering them below the temperature at which the reaction sustains itself, and with a large battery array such as that in an electric vehicle this can mean applying water for a prolonged period. It may even be necessary to keep cooling a battery for hours, or in some cases days, after the visible fire is out, to prevent it reigniting. The broad strategy, as set out in the fire safety guidance, is a combination of containment, reducing the fire's intensity, and steady cooling, to limit the spread to neighbouring cells while the original cell fire burns itself out.
This is demanding work even for the fire and rescue service, with the right equipment, training and water supply. It is not something an untrained person can replicate safely, and that is the heart of the matter for anyone who is not an emergency responder.
The message for almost everyone: get out, stay out, call 999The National Fire Chiefs Council is unambiguous on this point. If an e-bike, e-scooter or other lithium-ion battery catches fire, do not attempt to extinguish it. The speed at which these fires develop, and the toxic gases they produce, mean that the safe response is to leave immediately, close the door behind you if you can, raise the alarm, and call 999 from a safe place. Property can be replaced, and no one should put themselves between a venting battery and their way out.
First-aid options, and their limits
There are tools designed for the very earliest, incipient stage of a small lithium-ion battery fire, but they come with significant conditions and they do not change the advice above for untrained occupants. Aqueous Vermiculite Dispersion extinguishers, applied directly to the cells, deliver a thermally insulating, water-retaining film that both cools and limits the spread of thermal runaway to adjacent cells. Specially constructed fire blankets and fire suppression granules can help control a small battery fire by smothering and containment, and for a small device that is overheating but can still be safely handled, proprietary fire containment bags exist.
The conditions attached to all of these matter. They are intended only for incipient fires, only where it is safe to act, and only in the hands of suitably trained personnel with appropriate protective equipment, and their use should sit within a fire risk assessment carried out by a competent person, supported by training and proper servicing. It is also worth knowing that AVD extinguishers are not currently compliant under BS 5306, the standard for fire extinguishing equipment on premises, though they may still be considered fit for purpose as a first-aid tool for incipient fires under those same conditions. For a workplace where batteries are used or charged in any quantity, these options are part of a managed system, not a substitute for evacuation.
The real control is preventing the fire
Given how hard these fires are to extinguish, the most effective form of control by far is keeping them from starting, and the established guidance for everyday use is consistent and practical. Batteries and chargers should be bought from reputable suppliers, since counterfeit and substandard products are a recurring cause of fires, and only the manufacturer's approved charger should be used. Batteries should be charged while someone is awake and able to respond rather than overnight or when the property is empty, kept away from combustible materials and from heat, and never left covered while charging. Damaged batteries should be taken out of use, and end-of-life cells should be recycled properly rather than put in general waste, where they cause fires in bins and recycling vehicles.
Storage deserves particular thought in shared and residential buildings. The NFCC advises strongly against charging or storing e-bikes and e-scooters on escape routes or in the communal areas of a multi-occupied building, because a battery fire there can cut off the very route people need to get out. For anyone responsible for a block of flats or an HMO, this is now a central fire safety consideration, and the building's evacuation arrangements should account for where these products are charged and kept. Good detection helps too, with heat alarms generally recommended over smoke alarms in garages or kitchens where bikes are charged.
For workplaces that charge or store batteriesWhere lithium-ion batteries are used, charged or stored as part of a business, the handling, storage, use and charging of those batteries should be covered explicitly by the fire risk assessment, undertaken by a competent person. For premises charging electric vehicles, that extends to segregating charging areas, providing suitable automatic fire detection, arranging safe electrical isolation, and ensuring staff know how to raise the alarm and evacuate rather than tackle a battery fire. Emergency procedures and staff training should include clear instructions for dealing with a damaged or failing battery.
The pattern across all of this is consistent. A lithium-ion battery fire is something to escape from and report, not something to fight, and the genuine opportunity to control the risk lies in how batteries are bought, charged, stored and assessed long before any fire begins. As independent assessors covering the North West, North Wales and the West Midlands, we help building owners and employers build those controls into their fire risk assessment and their day to day management, so that the risk is addressed where it can actually be influenced.
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Get in touch Fire Risk AssessmentsThis article is provided for general guidance and does not constitute professional advice for any specific premises. It draws on RISCAuthority and Fire Protection Association guidance (including RE1, RE2 and RC59) and National Fire Chiefs Council guidance on e-bikes and e-scooters. In the event of any fire, the priority is to evacuate and call 999. Considerable care has been taken to ensure accuracy at the time of writing, but guidance changes over time. Fletcher Risk Management Limited provides Fire Risk Assessments, Fire Door Inspections and Fire Safety Training across the North West, North Wales and the West Midlands.