Lithium Batteries

BACKGROUND

“Lithium battery” or “lithium cell” is a collective term for a wide range of battery systems containing lithium in its pure or compound form as an active material in the battery electrodes. Nowadays there is an almost endless array of lithium batteries for a wide range of applications and technologies, for example, from use in consumer electronics, medical and industrial equipment, through to powering all-electric or hybrid vehicles, and for large scale energy applications.

It is not the intention of this Technical Bulletin to demonise lithium battery technology on which so many people and businesses throughout the world are becoming ever increasingly dependent. However, numerous incidents of lithium battery fires have been reported and close attention is needed to ensure that adequate precautions are put in place to minimise the fire/explosion risk and to improve safety.

Lithium batteries are separated into the following types:

Lithium metal batteries. Non-rechargeable/disposable batteries (commonly referred to as “primary batteries”) containing lithium metal which is highly combustible. Commonly used in small portable electronic devices such as watches, calculators, remote door locks, and back-up batteries in computers and communications equipment.

Typical primary lithium metal batteries

Lithium-ion (Li-ion) batteries. Rechargeable batteries (commonly referred to as “secondary batteries”) which although containing no free lithium metal, do contain lithium ions and highly flammable electrolytes. Common applications include laptops, mobile phones, GPS navigation devices, cameras, power tools, hybrid vehicles, hospital equipment and energy storage systems. Small electronic devices such as mobile phones are normally powered by a single cell Li-ion battery. For larger electronic devices such as laptops, power tools and test instruments, multi-cell battery packs are normally employed.

A selection of typical consumer electronics Li-ion cells

A selection of typical consumer electronics Li-ion battery packs

Lithium polymer (Li-pol) batteries. Rechargeable batteries of similar technology to Li-ion batteries, but with the main difference being that their design allows the elimination of a rigid metal case with a flexible foil like polymer laminate which may be suitably shaped for a specific application. The lack of casing results in a lighter battery and owing to the denser packaging without spaces between cylindrical cells, the energy density of lithium polymer batteries may be some 20% higher than a similar lithium ion pack. As a result, Li-pol batteries have gained particular favour in the world of radio controlled model planes and cars, but also have a range of other applications.

Typical Li-pol batteries

Li-pol batteries are especially hazardous if not stored, charged or handled correctly, and waste batteries require particular close attention. Li-pol batteries should be stored and charged in a proprietary fire safe container and should not be left on charge outside normal working hours.

A proprietary Li-pol safety charge sack

LITHIUM BATTERY FIRE BEHAVIOUR

Lithium batteries are capable of spontaneous ignition and subsequent explosion due to overheating. Overheating may be caused by electrical shorting, rapid discharge, overcharging, manufacturers defect, poor design, or mechanical damage, among many other causes. Overheating results in a thermal runaway, which is a reaction within the battery causing internal temperature and pressure to rise at a quicker rate than can be dissipated.

Once one battery cell goes into thermal runaway, it produces enough heat to cause adjacent battery cells to also go into thermal runaway. This produces a fire that repeatedly flares up as each battery cell in turn ruptures and releases its contents. The result is the release of flammable electrolyte from the battery and, in the case of disposable lithium batteries, the release of molten burning lithium. These fires can’t be treated like “normal” fires and require specific training, planning, storage, and extinguishing interventions.

As a result, lithium cells and batteries, including those that are packed with or contained in equipment are classified under the Carriage of Dangerous Goods and Use of Transportable Pressure Equipment Regulations as Class 9 Miscellaneous Dangerous Goods.

In summary, to be passed for shipment, lithium cells and batteries must be:

Manufactured under a quality management programme.
Of a design type that has passed physical testing in accordance with the UN Manual of Tests and Criteria.
Packed in accordance with the UN Model Regulations and relevant transport regulations (including marking and labelling to identify the contents).

FIRE SAFETY MANAGEMENT

Key to managing the risks posed by Li-ion and Li-pol batteries is to ensure that the handling, use (including charging) and storage of such batteries is the subject of a suitable and sufficient fire risk assessment, arising from which a proportionate programme of risk mitigation measures should be implemented. Such measures include, but are not limited to, the following:

Batteries should be sourced from proven, reputable manufacturers where they are produced and tested to rigid industry standards/protocols.
Pre-defined standard safe operating procedures and emergency response plans should be established on which all key employees are instructed and trained.
All batteries should be stored, charged and used in accordance with the manufactures’ instructions, ensuring that the correct charging equipment is employed at all times. Battery charging should not be carried out when buildings are unoccupied.
Care should be taken to ensure that batteries are not damaged whilst in storage, in use or on charge. Batteries which are found to be damaged, punctured or dented must be immediately taken out of service and quarantined remotely to await safe disposal
Measures should be taken to avoid battery shorting leading to overheating, burns or ignition. Batteries should not be carried in pockets and care taken to ensure that tools used for battery installation and maintenance are electrically insulated.
Batteries should not be stored close to heating equipment, and exposure to direct sunlight for long periods avoided.
When not in use, lithium-ion batteries should ideally be kept in a bespoke enclosure such as a proprietary metal battery storage cabinet or a fireproof safety bag. Alternatively, a steel cabinet installed with an internal automatic fire suppression system might be considered

Suitable fire extinguishers should be provided. (Extinguishers specifically for lithium battery fires have been developed employing Aqueous Vermiculite Dispersion – such as those depicted in the following link Lithium Battery Fire Extinguishers (lithium-battery-fire-extinguishers.co.uk ).
Infra-red thermographic inspections should be carried out on each battery package on arrival, and immediately prior to despatch. In addition, routine thermographic and visual inspections of battery stacks should be conducted at least daily. Any adverse temperature fluctuations are to be reported immediately and the emergency response plan initiated.
Rigorous inspection should be undertaken of all product returns owing to the potential increase risk of battery damage.
Where appropriate, batteries should be stored in a separate fire compartment of at least 120mins fire resistance, or in a non-combustible external container positioned at least 3m from other buildings, structures, equipment and storage. As a minimum requirement, battery storage should be strictly confined to a designated area with limited stack heights and appropriate spatial separation.
Smoke detection systems (ideally combined smoke and carbon monoxide detection) should be provided for all battery storage facilities and compartments.
In the case of large scale racked storage, an automatic fire suppression system should be installed, which in the case of sprinklers should include in-rack protection. When considering fixed fire suppression, specialist advice should be sought as to the most effective system for the particular application.
Small stocks of batteries should be contained in a fire-resisting cabinet. Alternatively, a steel cabinet installed with an internal automatic fire suppression system might be considered.

WASTE BATTERY MANAGEMENT

The manufacture and safe disposal of batteries is the subject the Waste Batteries and Accumulator Regulations 2009 (the Regulations).

From 1 February 2010 it has been a requirement for retailers who sell 32kg or more of portable batteries annually to have to accept waste portable batteries back from the general public. With the ever increasing lobby for environmentally safe battery disposal, public buildings such as libraries and other facilities have also become involved in voluntary waste battery collection.

Under the Regulations, businesses that are in possession, or have control of waste batteries have a legal duty to ensure that the waste is stored safely, managed properly, recovered or disposed of safely, does not cause harm to human health or pollution of the environment, is only transferred to someone who is authorised to receive it and, when transferred, is described in sufficient detail to allow subsequent holders to handle it safely.

The potential fire/explosion hazards of lithium batteries are such that close attention should be given to waste collection and storage, with special considerations applying to Li-pol batteries.

Recommendations relating to the collection and safe disposal of waste lithium batteries in the workplace include the following:

Battery terminals should be taped or protected with plastic covers to prevent shorting.

Small non-combustible receptacles should be used to collect waste batteries in the workplace, the contents of which should be periodically transferred to a larger external container which should be shielded from sunlight. Collection points should not be sited on fire escape routes.
Care should be taken to ensure that extraneous metallic items are not introduced into waste battery containers.
Waste Li-pol batteries should be packaged individually in a proprietary fire safe container and removed from the premises as soon as they are identified. Outside the premises they should be segregated from other batteries and placed in a closed metal container to await safe disposal.

SURVEY EXPECTATIONS

Consultants should remain aware the fire/explosion hazards associated with lithium batteries and appropriate investigations in the field are to be made. Most laptops and mobile phones, for example, are powered by lithium batteries and whilst their presence in most occupancies is a normal feature of the risk, it would be hoped that in any extensive facility, management have at least a basic awareness of the hazards which lithium batteries pose and the general fire safety measures that should be taken in relation to the storage and handling of spare batteries, charging and safe battery disposal. Where this is not the case, risk improvements should be raised as appropriate.

Retail and other premises where waste batteries are collected require special attention.

Dealing with the bulk storage of lithium batteries, including those contained or packed with equipment such as can be found in manufacturing, retail and distribution premises, appropriate details of such materials and the storage arrangements employed should be contained in the survey report and risk improvements raised as required, based on the guidance in this Technical Bulletin.

FURTHER REFERENCE

Further information concerning batteries and charging is contained in the following RISCAuthority publications:

RC61: Recommendations for the storage, handling and use of batteries
RC59: Recommendations for fire safety when charging electric vehicles
RC11: Recommendations for the use of fork-lift trucks

RC61 is a publication dealing with the fire safety of batteries in general and, as such, is considered an essential point of reference.

Specific RISCAuthority publications concerning lithium-ion batteries comprise:

Need to know guide RE1 - Battery energy storage systems: Commercial lithium-ion battery installations
Need to know guide RE2: Lithium-ion Battery Use and Storage

The Fire Industry Association paper entitled Guidance on Li Ion Battery Fires (fia.uk.com) is also an excellent source of information with regards to fire protection arrangements specific to Li-ion battery exposures.

ADDENDUM - E-BIKES AND SCOOTERS

In response to an increasing number of fires involving the charging or storage of e-bikes and e-scooters (privately owned e-scooters and e-unicycles have been banned for safety reasons on London’s tubes and busses by Transport for London since December 2021, following incidents of e-bikes catching fire) the NFCC has published an informative guidance document for use by Fire and Rescue Services and the public at large, the text of which is transcribed below:

E-bikes and e-scooters are becoming increasingly popular. Most are powered by lithium-ion batteries which can be charged in the home. The use of these batteries in a wide range of household products is becoming increasing common.

It is important when charging e-bikes and e-scooters, you do so safely to avoid a risk of a fire starting and putting your families and homes at risk.

With an increased use of e-bikes and e-scooters, comes a corresponding fire safety concern associated with their charging and storage. The use of these products is expected to continue to rise. Some fire services and fire investigators have seen a rise in e-bike and e-scooter battery fires.

Currently there is limited data relating to the number of fires, but London Fire Brigade reported 8 fires caused by e-bikes and e-scooters in 2019. This rose to twenty-four in 2020 and fifty-nine by December 2021.

On occasions batteries can fail catastrophically, they can ‘explode’ and/or lead to a rapidly developing fire.

The incorrect disposal of lithium-ion batteries in general household and recycling waste can lead to significant waste fires. Prevention messaging is therefore important in supporting both FRS protection and operational staff.

Key messages

The following messages can be useful in communicating the risk and minimising the risk of fire to the public:

Charging

Follow the manufacturer’s instructions when charging and always unplug your charger when it’s finished charging.
Ensure you have working smoke alarms. If you charge or store your e-bike or e- scooter in a garage or kitchen ensure you install detection, we recommend heat alarms rather smoke detectors for these areas.
Charge batteries whilst you are awake and alert so if a fire should occur you can respond quickly. Don’t leave batteries to charge while you are asleep or away from the home.
Always use the manufacturer approved charger for the product, and if you spot any signs of wear and tear or damage buy an official replacement charger for your product from a reputable seller.
Do not cover chargers or battery packs when charging as this could lead to overheating or even a fire.
Do not charge batteries or store your e-bike or e-scooter near combustible or flammable materials.
Do not overcharge your battery – check the manufacturer’s instructions for charge times.
Do not overload socket outlets or use inappropriate extension leads (use un-coiled extensions and ensure the lead is suitably rated for what you are plugging in to it).
In the event of an e-bike, e-scooter or lithium-ion battery fire – do not attempt to extinguish the fire. Get out, stay out, call 999.

Storage

Avoid storing or charging e-bikes and e-scooters on escape routes or in communal areas of a multi occupied building. If there’s a fire, it can affect people’s ability to escape.
Responsible Persons should consider the risks posed by e-bikes and e-scooters where they are charged or left in common areas such as means of escape, bike stores and mobility scooter charging rooms. They may wish to offer advice to residents on the safe use, storage and charging of these products.
Store e-bikes and e-scooters and their batteries in a cool place. Avoid storing them in excessively hot or cold areas.
Follow manufacturer’s instructions for the storage and maintenance of lithium -ion batteries if they are not going to be used for extended periods of time.

Buying

Buy e-bikes, e-scooters and chargers and batteries from reputable retailers.
Many fires involve counterfeit electrical goods. Items which don’t meet British or European standards pose a huge fire risk and while genuine chargers (or battery packs) may cost more, it’s not worth putting your life at risk and potentially destroying your home by buying a fake charger to save a few pounds.
If buying an e-bike conversion kit, purchase from a reputable seller and check that it complies with British or European standards. Take particular care if buying from online auction or fulfilment platforms. Also be aware that if buying separate components, you should check that they are compatible.
Register your product with the manufacturer to validate any warranties – batteries are usually included in warranties. Registering makes it easier for manufacturers to contact you in the event of safety or recall information.
Check any products you have bought are not subject to a product recall. You can do this but checking Electrical Safety First’s website or the government website.

Damage and disposal

Batteries can be damaged by dropping them or crashing e-bikes or e-scooters. Where the battery is damaged, it can overheat and catch fire without warning. Check your battery regularly for any signs of damage and if you suspect it is damaged it should be replaced and should not be used or charged
If you need to dispose of a damaged or end of life battery, don’t dispose of it in your household waste or normal recycling. These batteries, when punctured or crushed can cause fires in bin lorries, recycling and waste centres. Your e- bike or e- scooter manufacturer may offer a recycling service. Alternatively check with your local authority for suitable battery recycling arrangements in your area.

Enjoy and ride your e-bike or e-scooter safely and ensure you are using these products within the law. Further information can be found here https://www.gov.uk/electric-bike-rules

Consultants should remain alert to the hazards associated with the charging and storage of e-bikes and e-scooters, particularly when conducting surveys of blocks of flats, student accommodation and other residential buildings. A risk improvement wording has been added to the database directed to property owners, facilities managers, managing agents and others with a responsibility or an involvement in fire safety management.