Most lithium-ion safety writing talks about fire. The Australian Maritime Safety Authority safety lesson published on this incident is a useful correction, because the vessel was not lost to fire. It was lost to an explosion. AMSA records evidence of smoke and fire on board, but states plainly that the destruction was caused by the blast itself (Australian Maritime Safety Authority [AMSA], 2025).

That distinction matters for anyone who charges batteries indoors, in a plant room, in a shipping container, in a garage, or in a locked store cupboard. Fire gives you smoke, alarms and time. A gas explosion gives you none of those.

What happened

A charter fishing vessel was berthed when it exploded at 11.30 pm. The force scattered debris up to 30 metres and ejected a 200 kg deck winch along with a section of deck, which landed at the vessel’s stern. No one was on board and no one was injured. The vessel was assessed as beyond repair (AMSA, 2025).

The lead-up is the part worth reading twice. The owner had been having trouble with the lithium-based battery system attached to the pot winch. On the afternoon of the incident they bought a new charger and paid an auto electrician to install it. The electrician fitted the new charger temporarily to the system so it could be left charging overnight, set the charger, and left the vessel at around 7.30 pm. The explosion followed roughly four hours later (AMSA, 2025).

The two findings that matter

AMSA notes that the damage made firm conclusions difficult, but the investigation identified two issues that anyone running a battery installation can check tomorrow morning.

The battery management system was potentially bypassed. The temporary installation of the new charger appears to have gone around the BMS. A BMS is the only thing standing between a degraded cell and an overcharge event. Wire a charger straight to the pack and the protection is not degraded, it is simply absent.

The battery location was not ventilated as required by the Australian Standards. AMSA states that lithium-ion batteries on domestic commercial vessels must be installed in accordance with the National Standard for Commercial Vessels Sub-section C5B Electrical, that installations must include an approved battery management system, and that ventilation air flows must follow the manufacturer’s specification (AMSA, 2025; AMSA, n.d.).

Those two failures compound each other. The bypassed BMS allowed a fault to develop. The unventilated compartment turned the product of that fault into a bomb.

Why it exploded instead of burning

When a lithium-ion cell enters thermal runaway it does not simply catch alight. It vents. The cell breaks down internally and pushes out a large volume of hot gas, and a significant fraction of that gas is flammable.

Testing on NMC pouch cells recorded gas volumes of up to 102 litres from a single cell, with the volume scaling with cell capacity. Carbon monoxide reached 16.85% by volume, methane 7.6% and ethylene 7.86%, all within their explosible range. Applying Le Chatelier’s law to the mixture gave a lower explosion limit of 7% by volume and an upper explosion limit of 31% (Amano et al., 2023). This is the study AMSA itself cites in the safety lesson.

Read that as a sequence rather than a set of numbers. A cell fails. It vents flammable gas into an enclosed compartment. With no ventilation, the concentration climbs through the lower explosion limit. Somewhere in that space there is an ignition source, and on a boat mid-charge there are several. The result is not a fire that a crew member notices and responds to. It is a deflagration that removes the deck.

The gas is also acutely toxic. Full-scale testing has measured substantial hydrogen fluoride release from lithium-ion cells during fire, at levels relevant to occupant survivability even where the fire itself is modest (Larsson et al., 2017). Anyone who has ever thought about opening a smoking battery cupboard to have a look should sit with that.

The warning that was already there

The single most repeatable lesson in this report is buried in one clause. The battery was not holding charge.

That is the point where the story could have ended differently. A battery that will not hold charge is not a charging problem to be solved with a better charger. It is a battery telling you that something inside it has changed. UK guidance for vessels lists exactly this alongside bulging, leaking, excessive heat and BMS trips as an indicator that a battery may be about to vent, ignite or explode, and advises isolating the battery and charger and arranging safe disposal rather than continuing to use it (Boat Safety Scheme, n.d.).

Instead, a new charger was bought, fitted temporarily, and the pack was left charging unattended overnight in an unventilated space. Every one of those four decisions is common. None of them is unusual. That is precisely why the incident is worth circulating.

This is not only a boat problem

Swap the vessel for any confined space where charging happens and the physics do not change. The pattern repeats in:

• Domestic garages and under-stair cupboards where e-bikes and scooters charge overnight
• Plant rooms, comms rooms and battery cabinets in commercial buildings
• Shipping containers and site sheds used as charging or storage points
• Ute canopies, service body drawers and enclosed van racking with tool batteries inside
• Store rooms in aged care and healthcare where mobility devices are charged out of sight
• Workshop mezzanines and racking where forklift and AGV packs sit on charge unattended

The regulator language differs by sector, but the control set does not. The United States Coast Guard issued a marine safety alert in July 2025 after an integrated lithium-ion bank caught fire on an inspected passenger vessel when loosely crimped lugs overheated, and its recommendations run to plan review, supporting safety systems, installation and periodic testing, visual inspection for signs of deterioration, and crew trained to respond to abnormal battery conditions (United States Coast Guard, 2025). The European Maritime Safety Agency’s guidance for battery energy storage systems on ships is built around the same premise, that fire and explosion from thermal runaway and off-gassing are the defining risks and must be designed against rather than fought after the fact (European Maritime Safety Agency, 2024).

None of that is exotic. It is a plan review, a ventilation path, a competent installer, an intact BMS, and someone who inspects.

What a charging procedure should actually cover

AMSA’s safety message is that owners and operators should develop and implement a procedure for onboard charging of electronic devices and battery systems, and that the procedure should consider the risk of thermal runaway including the venting of toxic and flammable gases (AMSA, 2025). Written well, that document is one page. It should answer:

• Where charging is permitted, and where it is banned. Nominate the location rather than leaving it to whoever is holding the charger.
• Whether that location is ventilated to the manufacturer’s specification, and who verified it.
• Who is allowed to alter a battery installation. A temporary charger fit-up is an alteration.
• That the BMS must remain in circuit, always, including during temporary or diagnostic work.
• What happens when a battery will not hold charge, bulges, leaks, smells, gets hot or trips its BMS. The answer is isolate, quarantine and dispose, not persist.
• Whether unattended overnight charging is permitted at all, and if so under what detection.
• Detection and alarm: is there a smoke or heat alarm covering the charging point, and can it be heard by someone who can act?
• The response. Get out, stay out, call 000. Do not open the compartment.
• Disposal, because a suspect battery sitting in a corner waiting for someone to deal with it is still a charged energy store.

If you want a starting point, our Business & Bulk page lists the site audit checklists and charging protocol documents we provide on request, and the Lithium Battery Fire Safety Awareness course covers the warning signs and the response sequence in a form you can issue to a whole crew and keep a training record for.

What equipment does, and what it does not do

We sell fire equipment, so we will be direct about the limits. Nothing in our range would have saved that vessel. Once a pack is venting flammable gas into a sealed compartment, the outcome is set by ventilation and ignition sources, not by what is hanging on the bulkhead. AMSA is blunt that these events lead to fires that are extremely difficult to extinguish (AMSA, 2025), and UK vessel guidance goes further and tells boaters never to attempt to fight a lithium-ion battery fire (Boat Safety Scheme, n.d.).

What equipment does do is buy time in the far more common scenario: a single device or small pack that starts misbehaving while someone is present and awake.

• Specialised lithium-ion extinguishers work by cooling. Our agent is a potassium acetate solution in a water carrier with a surfactant, designed to wet into the cell stack and pull temperature back below the runaway threshold so the reaction is less likely to reignite. They are certified to EN 3-7:2004+A1:2007. They are a supplementary measure, not a substitute for your statutory fire safety measures.
• Fire blankets contain and shield. They do not extinguish thermal runaway. They limit radiant heat and reduce spread to what is next to the device while you get people out.
• Containment bags are the control for the warning-sign stage described above. A battery that has been isolated and is waiting for disposal should not be sitting loose on a bench. Ours are rated to 1100°C instant and 550°C continuous.
• Signage and PPE matter more than people expect. Marking the charging point and the equipment location is what makes a procedure real rather than filed.

An honest note on Australian certification: AS 1841 still has no lithium-ion classification, so there is no Australian certification pathway for a lithium-ion extinguisher at present. We say so rather than implying one exists.

The one-line version

A battery that would not hold charge was connected to a new charger that appears to have bypassed its safety system, in a space that was not ventilated, and left overnight. Four hours later the vessel was gone. Check your BMS is in circuit, check your charging space vents, and treat a battery that will not hold charge as a battery that is telling you something.