With the UK facing a mounting stockpile of used EV batteries, the risks of unsafe storage are rising.
The UK has been an early mover on EV adoption, with aggressive, legally binding climate targets, pioneering early incentive schemes and grants, and a rapidly expanding charging network all pushing it towards a greener future.
But beneath the surface, a challenge is building – tens of thousands of used EV and energy storage batteries are piling up in the UK, with around 23,500 end-of-life batteries sitting in storage rather than being reused or recycled, according to an FT article[1].
For warehouse and storage managers, recyclers, waste contractors and regulators, the challenge is clear: damaged or poorly stored batteries pose a real and growing fire and environmental risk.
Yet as battery chemistries evolve and energy densities increase, traditional approaches to storage, handling and disposal are no longer sufficient.
Pete Zorgenlos, Head of Product Development (UK & Europe) at New Pig, offers his practical, expert-led guidance on how to safely manage damaged, defective or end-of-life lithium-ion batteries.
Navigating a shifting regulatory landscape
The regulatory environment in the UK is tightening in response to these growing volumes. With the Lithium-Ion Battery Safety Bill and the 2025 updates to the Hazardous Waste Regulations, the “best practice” of yesterday is quickly becoming the legal minimum of today.
In the UK, Li-ion batteries are classified as controlled hazardous waste, and the Environment Agency now demands rigorous tracking and separate collection. When these assets move from storage to transport, the requirements become even more stringent.
This shift places the burden of proof on the facility manager to ensure that every unit leaving the site is not only packaged in UN-approved containers but also chemically stabilised for the journey.
Expert protocols for safe management
Understanding the inherent hazards of Li-ion chemistry is essential for effective risk mitigation. Unlike traditional lead-acid batteries, Li-ion cells contain a flammable electrolyte that can fuel its own fire without the need for external oxygen. Mechanical damage, manufacturing defects, or even minor electrical faults can trigger an exothermic reaction known as thermal runaway.
In a high-density storage environment, this poses a unique threat: the “domino effect,” where the heat from one failing cell compromises its neighbours. This process is remarkably rapid, reaching temperatures between 700°C and 1000°C in seconds, often accompanied by the release of toxic hydrofluoric acid vapours.
Effective management begins with early detection. Strategic handling should focus on identifying the “warning signs” of failure – such as swelling, hissing, or discolouration – before an incident occurs. Expert guidance suggests that suspect batteries should be immediately isolated.
For safe storage while awaiting proper disposal, the battery should be placed in a container filled with cushioning material that is non-combustible, electrically non-conductive, and absorbent.
This “triple-threat” of protection, using specialist non-combustible binders, ensures that if a cell does breach, the impact is contained. Under no circumstances should damaged batteries be placed in regular trash or recycling containers, as this introduces an unacceptable fire risk to the wider waste stream.
Where high-risk or significantly compromised units are identified, further measures may be required, including placing the battery within a specially designed, fire-rated storage case to provide an additional layer of thermal protection.
The physical environment of the storage facility also plays a critical role in battery longevity and safety. Maintaining a stable temperature profile – ideally between 4°C and 27°C – prevents the chemical degradation that leads to internal short circuits.
In the UK’s increasingly volatile weather patterns, climate-controlled storage is no longer a luxury for large-scale stockpiles, it is a fundamental requirement for maintaining the “second-life” value of the battery while ensuring site safety.
Proactive electrolyte leak management
A critical, yet often overlooked, aspect of battery safety is the management of minor leaks during the manufacturing and storage phases.
In instances of minor cell compromise, specialist absorbent mats can be deployed to catch drips and leaks. It is essential that these are composed of chemical-resistant materials specifically designed to absorb lithium-ion battery electrolytes without degrading or triggering a secondary reaction.
Modern industrial solutions offer a technical advantage in these environments. These mats are engineered using a high-absorbency, fine-fibre construction that wicks liquid quickly through an exclusive dimple pattern, ensuring a faster clean-up and a safer floor surface.
Because these mats are specially treated to remain structurally sound even when saturated – lasting up to twice as long as standard alternatives – they provide a reliable line of defence. Whether utilised in roll form to cover large areas or as lightweight pads for smaller tasks, having these materials on hand allows facilities to manage hazardous spills without leaving behind residue or compromised fibres.
Emergency response: cleaning up electrolyte spills
While electrolyte leaks from a damaged battery pack are relatively infrequent, they present immediate hazards to both personnel and the environment.
In the event of a spill, a disciplined response procedure is vital. The spill must be contained by a trained operative if safe to do so and the area ventilated and evacuated for large spills. It is also critical to keep appropriate firefighting measures, such as specialist battery fire suppressants or fire blankets, within immediate reach during the clean-up.
The leaking battery should be carefully placed in a container of chemically inert cushioning material. To address the spilled fluid itself, only inert, non-cellulose absorbents should be used, as cellulose-based materials can react unfavourably with certain battery chemistries.
Once the area is clear, all used absorbents and contaminated PPE must be secured in a sealed bag. Proper disposal is not merely a housekeeping task but a regulatory one; you must contact your environmental or shipping officer to arrange for hazardous waste collection, as neither the batteries nor the spent absorbents can be disposed of in standard waste or recycling streams.
Beyond compliance
As we move toward a circular economy, the ability to safely handle, store, and document the lifecycle of lithium-ion assets will separate the industry leaders from those exposed to significant liability.
Ultimately, safe storage is about more than just avoiding a fire; it is about protecting the financial and environmental value of the UK’s energy transition.
By embedding these expert-led protocols into organisational culture, we ensure that the lithium-ion legacy remains a cornerstone of the UK’s net-zero future, rather than a hidden risk.
For more visit: www.newpig.co.uk
[1] https://www.ft.com/content/cc5ef169-fac1-4af0-9b99-1edd360325e4