Lithium-Ion Battery Fire Risk Assessments

There is no single piece of English law about lithium-ion batteries in buildings. The duty comes from the Regulatory Reform (Fire Safety) Order 2005 and the Health and Safety at Work etc. Act 1974, applied through risk assessment. Product safety is governed separately and is changing. The Product Regulation and Metrology Act 2025 received Royal Assent in July 2025 but it is an enabling Act. It confers power to make secondary legislation on product safety, including for lithium-ion batteries and online marketplaces. The substantive requirements will come from regulations made under it and those had not been delivered at the time of writing so nobody should be told the law has already changed.

PAS 63100:2024 and the gap it leaves

PAS 63100:2024, "Electrical installations. Protection against fire of battery energy storage systems for use in dwellings. Specification", was published on 20 March 2024. It covers small scale electrical energy storage in domestic dwellings using stationary secondary batteries: physical battery requirements, battery management, power conversion, fault management, installation location, marking and verification.

Its principles are sound and transferable. Install outside the dwelling and away from habitable rooms wherever practicable. Separate the battery from habitable rooms and from means of escape by suitable fire compartmentation. Provide fire detection at the battery location, interlinked to a fire alarm system. Keep escape routes unobstructed.

The exclusions are the part people miss. PAS 63100 does not apply to higher-risk residential buildings, to dwellings over 200 square metres, to systems exceeding the low voltage limits in BS 7671, to batteries under 150 watt hours within certain products, to second-life batteries or to battery transportation. It does not cover e-bikes, e-scooters or any mobile battery at all. It is voluntary, is not cited in the Approved Documents and is not law. It is the reference insurers, MCS installers and competent person schemes use.

E-bikes, e-scooters and residential buildings

National Fire Chiefs Council guidance on e-bikes and e-scooters is the recognised advice. Follow the manufacturer's instructions. Use approved chargers only. Unplug when charging is finished. Never charge unattended or overnight. Do not cover the charger. Store batteries somewhere cool, away from extremes of heat and cold and not on escape routes or in communal areas. Dispose of damaged batteries through a proper recycling route.

Two honest points sit behind that. NFCC guidance creates no duty of its own. And there is currently no English statutory prohibition on charging an e-bike in a common part. The control comes from your fire risk assessment, your lease or tenancy terms and the responsible person's general duties, which means the rule has to be written somewhere enforceable before anyone can enforce it. Writing a prohibition into a fire risk assessment with no route to enforce it and no alternative charging provision, produces charging behind closed doors instead of in the bin store.

London Fire Brigade recorded 206 e-bike and e-scooter fires across London in 2025, of which 171 involved e-bikes and reported two deaths in London that year. Those are London figures for London and should not be presented as a national picture.

Battery energy storage systems

Domestic units fall within PAS 63100 and can be assessed against it directly. Anything larger and anything in a higher-risk residential building, falls outside it. For those we work from first principles: siting and separation distance, fire resisting construction or a detached enclosure, ventilation and gas dispersal, detection type and position, access for the fire and rescue service, water supply, run off containment and the emergency plan for a unit that cannot be approached. We say plainly where the guidance runs out rather than dressing a judgement up as a standard.

Waste and recycling streams

Batteries dropped into general or mixed recycling waste are crushed in the collection vehicle or at the transfer station and start fires there. The mechanism is well established and is the reason the disposal advice exists. For waste operators the assessment covers infeed screening, quarantine arrangements for damaged, swollen or water-damaged cells, pile size and separation, thermal imaging or hot spot detection and the fire plan for a burning pile that cannot be broken up safely. The Environment Agency has consulted on appropriate measures for waste batteries at permitted facilities. We check the current published status of that guidance for your permit rather than assuming it.

1. 01

   Scoping call

   We establish the building type, the battery population and what has already been asked for by an insurer or a regulator.

2. 02

   Survey

   We walk the charging and storage locations, look at what residents or staff are actually doing rather than what the notice on the wall says and photograph the findings.

3. 03

   Assessment

   We work each scenario through from cell failure to occupant escape, against PAS 63100 where it applies and against first principles where it does not.

4. 04

   Report and action plan

   Findings graded by risk, each with a named owner, a date and the reason it matters.

5. 05

   Integration

   We write the outcome into your fire risk assessment and your fire safety arrangements and give you the wording for tenancy, lease or workplace rules.

• Floor plans, including bin stores, cycle stores, plant rooms and any store cupboard on an escape route.
• Your current fire risk assessment and fire strategy.
• An inventory of batteries and chargers where one exists and honest input where one does not.
• Tenancy agreements, leases or workplace rules that currently mention charging.
• Any insurer correspondence, survey report or policy condition on the subject.