In an interview with Carly Weller, Mishaal SyedNaveed, Product Manager – Fire Protection at Wärtsilä Energy Storage, explained how the company’s recent Quantum3 safety tests not only met existing standards but also set new benchmarks for battery fire safety testing.
Battery energy storage systems are scaling rapidly to meet the demands of utilities, data centres and industrial customers, and with that growth comes heightened scrutiny of safety.
Fire resilience has become the defining benchmark for credibility, and the latest entrant to the market – Wärtsilä’s Quantum3 – is positioning itself as a leader in this space. Due to launch in early 2026, Quantum3 is a 5MWh AC block battery energy storage system that has recently undergone a series of rigorous fire and explosion tests.
Wärtsilä has successfully completed three major fire safety and explosion tests for Quantum3. The programme included UL 9540A unit-level testing, Large Scale Fire Testing, and Wärtsilä’s proprietary Active Ignition Mitigation System (AIMS) testing.
Each test was designed to simulate worst-case fire and explosion scenarios and has confirmed Quantum3’s ability to contain thermal runaway events, prevent fire propagation, and mitigate risks associated with flammable gas build-up. CSA Group provided independent third-party test verification.
The foundation of modern battery fire safety testing lies in UL 9540A, a protocol designed to determine thermal runaway behaviour at multiple levels – from individual cells to modules and finally the full system.
Mishaal described UL 9540A as “a test standard or method of how to conduct fire testing from the cell module all the way to the unit level”, noting that it has been the industry norm for years. But the industry is shifting. Conventional standards once focused on small-scale, prescriptive tests – igniting a single cell and observing the outcome. Today, integrators are expected to prove resilience under large-scale fire testing, where entire units are deliberately set ablaze to assess whether flames propagate across containers.
“Typically you’ll have three containers side by side and then you’ll fully ignite the middle one and you see if that fire spreads laterally or adjacent”, Mishaal explained. This approach, he added, reflects a paradigm shift towards worst-case scenario testing, mirroring real-world site installations rather than laboratory abstractions.
Quantum3 has gone further than most competitors by introducing explosion control testing. Within the system, flammable gases released during thermal events are deliberately ignited to prevent dangerous build-up. Mishaal described this as “purposefully igniting any flammable gases that come off of these cells…by igniting those gases earlier, we’re able to manage that flammable gas build-up and thus relieve that overpressure.”
This proactive approach to explosion hazards represents a new frontier in battery safety, complementing fire resilience with off-gas management strategies. It also demonstrates a willingness to tackle hazards that are often overlooked in conventional testing regimes, where the focus has historically been on fire alone.
Mishaal explained that this was the fourth large-scale test Wärtsilä had completed, and the first to involve a fully populated AC block enclosure. Unlike many integrators, Quantum3 was tested with doors closed, simulating the most realistic installation conditions. Mishaal argued that this level of rigour distinguishes the company’s approach: “I will honestly say that ours is the best. Everyone says that, but I think our test is more rigorous than what I’ve seen in the market.” The emphasis here is not simply on passing a test but on replicating the conditions customers will face in practice, ensuring that safety claims are grounded in reality.
Underlying these safety results is a deliberate choice of chemistry. Early deployments relied heavily on nickel manganese cobalt (NMC), prized for its high energy density but increasingly recognised as volatile. Mishaal noted that “as testing continued, we noticed that NMC is more volatile compared to LFP.”
Today, LFP (lithium iron phosphate) is widely regarded as the safer option, with fewer links to industry incidents. “Out of all the chemistries for battery energy source systems that are lithium iron based, LFP is relatively the safest compared to all the other chemistries,” he said.
The industry-wide shift towards LFP reflects a prioritisation of safety over density, particularly as containerised systems grow in scale. Mishaal pointed out that larger footprints mean more energy density, which in turn means more fuel to burn if a fire does occur. Choosing LFP helps mitigate that risk.
For customers, the value of these tests lies in their realism. Mishaal emphasised that the company invites stakeholders to witness large-scale fire tests, ensuring transparency and confidence. “They know exactly what they’re getting is what they’re paying for”, he said. By replicating site installations as closely as possible, Quantum3’s testing provides assurance that performance in the lab will translate into resilience in the field. This approach is particularly important for utilities and data centres, where downtime or catastrophic failure can have far-reaching consequences.
Safety testing is not only about customer confidence but also regulatory compliance. Mishaal pointed to NFPA 855, the global standard for energy storage installation, as a key reference point. UK and EU regulators often derive their guidelines from NFPA, and the 2026 edition is expected to introduce new requirements.
“We anticipate some upcoming changes, especially for the EU and the UK market, which we’re well ahead of,” he said. The company is actively involved in shaping these standards, with colleagues sitting on UL technical committees and contributing to Energy Storage Europe (formerly EASE) discussions.
Industry incidents have played a crucial role in shaping testing protocols. Mishaal acknowledged that “we’ve conducted our testing to match as worst case as possible”, noting that the industry has evolved from “baby steps” with UL 9540A to full-scale fire scenarios. Beyond testing, the company integrates safety into site design and lifecycle support. Permitting packages, engagement with fire authorities, and emergency response training are all part of the offering. “We’re truly a partner in the life cycle of the project. We’re not here just to dump our batteries and leave,” Mishaal said. This philosophy reflects a broader shift in the industry towards holistic safety, where product design, site planning, and operational support are all aligned.
While Quantum3 is a grid-scale system, the principles of safety testing are being extended to smaller markets. Upcoming standards such as UL 9540B will address residential and lower-density systems, ensuring that lessons learned at utility scale are applied to commercial and domestic deployments. Mishaal noted that “everyone is now coming to a consensus of how to properly manage these types of systems,” suggesting that the industry is moving towards a unified approach across scales. This is particularly relevant as residential storage grows in popularity, driven by renewable integration and consumer demand for resilience.
Next-generation chemistries such as sodium-ion and solid-state batteries are also on the horizon. Mishaal revealed that the company has already conducted internal sodium-ion testing, though he cautioned that “it’s a little too early to implement that type of chemistry now, due to several factors”. Nevertheless, he expressed optimism that advanced testing will accelerate adoption once these chemistries mature, noting that sodium-ion fire behaviour appears similar to LFP. Solid-state batteries, with their promise of higher energy density and improved safety, will also require rigorous validation before widespread deployment. Quantum3’s testing philosophy – combining realism with innovation – provides a template for how these future chemistries might be assessed.
The broader implication of Quantum3’s testing programme is that safety is no longer a box-ticking exercise but a competitive differentiator. By demonstrating resilience under the harshest conditions, the company is not only reassuring customers but also setting a benchmark for the industry. This rigorous testing is likely to become a baseline expectation as regulators tighten standards and customers demand greater transparency.
Quantum3 represents a significant step forward in battery fire safety, combining established protocols with pioneering explosion control measures. By testing under the most realistic conditions, the system not only sets a new benchmark but also anticipates regulatory changes in the UK and EU.
