E-bikes, e-scooters, and energy storage systems are creating a new fire risk in UK buildings. With lithium-ion battery fires increasing 60% year-on-year, building owners and fire services face an evolving challenge.. A New Category of Fire Risk Lithium ion battery fires represent one of the most rapidly growing fire risks in the UK built environment. London Fire Brigade alone attended over 180 e bike and e scooter fires in 2025 — a 60% increase on the previous year. Three people died in these fires in London alone. These fires are fundamentally different from conventional fires. They develop explosively, produce extremely toxic gases including hydrogen fluoride, and are extraordinarily difficult to extinguish. A single e bike battery contains the energy equivalent of several hand grenades. Understanding Thermal Runaway Lithium ion battery fires begin with a process called thermal runaway : 1. Initiation — Internal cell damage (manufacturing defect, physical impact, overcharging) causes localised heating 2. Acceleration — Heat triggers exothermic decomposition of the cathode material 3. Propagation — Adjacent cells are heated above their critical temperature, creating a cascading failure 4. Venting — Cells vent flammable and toxic gases (including HF, CO, HCN) 5. Ignition — Vented gases ignite, often explosively 6. Sustained burning — The battery continues to supply fuel even without external oxygen The Building Risk Profile Residential Buildings E bikes and e scooters charged in hallways, bedrooms, and communal areas Converted or modified batteries with inadequate safety circuits Cheap, uncertified chargers that fail to regulate charging properly Charging overnight when occupants are asleep Commercial Buildings Battery Energy Storage Systems (BESS) for renewable energy Large scale UPS systems in data centres Warehouse storage of lithium ion products EV charging facilities in basement car parks Current UK Guidance and Regulation The regulatory framework is evolving rapidly: LFB safety advice — Do not charge e bikes/e scooters in escape routes NFCC position statement — Guidance for fire and rescue services Product safety regulations — Many fires involve non compliant products Building insurance implications — Some insurers now exclude or restrict cover Proposed legislation — Government consultation on product safety standards for e bikes and batteries Fire Safety Measures for Building Owners Residential Buildings 1. Policy — Establish clear rules on e bike/e scooter charging locations 2. Detection — Ensure smoke detection covers charging areas 3. Suppression — Consider sprinkler coverage in designated charging areas 4. Storage — Provide dedicated, fire separated charging/storage areas where possible 5. Communication — Educate residents about safe charging practices 6. Insurance — Review policy terms regarding lithium ion battery risks Commercial Buildings 1. BESS risk assessment — Site specific assessment of battery storage installations 2. Separation distances — Adequate clearance between BESS and buildings 3. Suppression systems — Purpose designed suppression for lithium ion fires 4. Ventilation — Ensure toxic gas venting is directed safely 5. Emergency response plan — Including specialist firefighting procedures 6. Monitoring — Continuous thermal monitoring of large battery installations Firefighting Challenges Lithium ion battery fires present unique challenges for fire services: Water can be counterproductive in some scenarios (risk of explosion on contact) Re ignition risk — batteries can re ignite hours or even days after apparent extinguishment Toxic atmosphere — HF gas requires specialist respiratory protection Thermal imaging limitations — battery casing can mask internal temperatures Disposal — even damaged batteries that haven't caught fire remain hazardous For lithium ion battery fire risk assessments and mitigation strategies, contact Magnus Opifex.