In this article, I do not plan to address the specific issues of lithium-ion (li-ion) battery fires on electric powered boats or ships, nor will I discuss the electric vehicles that have caught fire in high profile, well-reported incidents at sea in recent years, whilst being transported on board car carrying ships. That’s a topic for yet another day!
Neither is it my aim to scare people in what I hope is a well thought out article, that articulates and reflects where we are at in our current relationship with li-ion as a significant power source. There are millions of li-ion powered devices in existence throughout the world, and the vast majority perform their function without drama or malfunctioning. But there is growing evidence now to show that li-ion batteries, for all their good points, present some significant challenges when things go wrong, especially in the maritime sector.
For balance, it is important to state that statistically there is no evidence to suggest that a li-ion battery conflagration is more likely to occur than a conventional fire, but the reality is that when one does happen, the results are usually rapid and explosive often leading to a total loss. The inferno represents immediate danger to crew, passengers and the vessel itself, as well as neighbouring boats and even harbour infrastructure. Unlike a fire in an electric vehicle on the road, where the driver has an opportunity to pull over and effect an escape, that luxury is not afforded to those at sea should a similar emergency situation occur.
In recent years, the number of fires aboard vessels has risen dramatically. While there are many potential causes, li-ion batteries have been directly linked to, and proven to be the cause of a number of these incidents.
Li-ion batteries are commonplace these days and the plethora of high- end water toys and electric devices are causing catastrophic fires on boats, often due to overheating while charging, or damage in storage that has agitated the batteries. Some examples include e-scooters, e-bikes, drones, electric surfboards, seabobs, phones, tablets and so on.
Each of us personally could have up to half a dozen li-ion batteries in close proximity – a watch perhaps, laptop, mobile phone, handheld UHF radio, flashlights, other wearable tech, and even vapes – are just a few examples. Unfortunately, the power of li-ion batteries and their convenience come with risks that we need to be aware of so we can take mitigating action when and if required.
Lithium is a highly reactive alkaline metal and the chemistry behind li- ion batteries is complex. This makes it ideal for storing large amounts of energy in battery form but also makes it potentially explosive when something goes wrong. The key is in the construction of the cells which make up the particular battery type. When in use, electrons flow between the cathode and the anode through a perforated separator. If this membrane breaks down, either through poor manufacture, old age or mishandling, a short circuit can occur. Then the cell quickly heats up, the electrolyte expands and a toxic, flammable gas is vented, sometimes explosively. In bigger batteries with multiple cells, the heat starts to damage neighbouring cells, which then also malfunction. This process is called thermal runaway and once triggered, it is near on impossible to stop. When the cell is breached, highly reactive lithium simply adds fuel to the fire.
Thermal runaway is a dangerous, self-sustaining chain reaction in li-ion batteries where internal heat exceeds heat dissipation, leading to excessive temperatures. It causes rapid, uncontrollable temperature rises, releasing toxic and flammable gases – known as off gassing – and often resulting in fires or explosions. The toxic gages are a rarified mix of substances, and if inhaled could kill.
Fire suppression systems and extinguishers are not yet effective enough to guarantee to put out a li-ion fire once it has taken hold, and worryingly, there is an ongoing risk that the device could reignite hours, days, or even some weeks later after the event.
Case Study 1: Crude Tanker S-Trust fire caused by lithium-ion battery is investigation finding
The National Transportation Safety Board released an investigation report into the blaze on the bridge of the crude tanker S-Trust on 13 November 2022 when a fire started on the bridge of the crude tanker S-Trust. Fortunately, fire teams from the vessel’s crew extinguished the fire. The damage to navigation and communication equipment on the vessel was estimated at $3 million.
Investigators found the remains of three batteries (one nickel-metal hydride and two lithium-ion) on the communications table. The single nickel-metal hydride battery (all of its six cells) was intact; one of the lithium-ion batteries (both cells) was found intact in the remains of the chargers (one nickel-metal hydride charger and one lithium-ion charger). Investigators only found components of the second lithium-ion battery (a two-cell battery).
Case Study 2: Fire Service issues reminder on dangers of lithium-ion batteries following Gayton Marina boat fire
Early on the morning of 5 August 2025, a li-ion battery fire occurred at Gayton Marina in Northamptonshire on a day boat which had been left on charge overnight. It was the first known event of its kind on the UK canal network. The explosion literally shook the marina, the boats moored in it and rocked the wider canal community; yet this story did not make national news headlines.
Just moments before the local fire brigade were ready to start tackling the flames, the boat exploded with such force that it seems improbable anyone on board would have survived the blast. The results of any subsequent internal investigation, if indeed there was one, remain unknown.
Area Manager Neil Sadler, of Northamptonshire Fire and Rescue Service, said, “Lithium-ion batteries come in all shapes and sizes and are used in everyday items we all own, so we want to remind people of the hazards they can sometimes pose. “If they overheat or are punctured, crushed or overcharged, then they can release a flammable vapour which can ignite, burn or in some cases explode.
“We want to ensure people follow the appropriate safety advice to mitigate any risks that lithium-ion batteries can pose in products we use every day, such as mobile phones, electric cars, charging devices and tools.
“The main advice is for people not to put these batteries in the bin. Make sure you take them to your local household recycling centre so that staff there can dispose of them safely.”
Protection is key and there are some simple yet essential things that can be done
In most cases, regulators remain behind the curve as far as li-ion battery technology is concerned. However, there are industry guidelines emerging as more becomes known. The US Coast Guard Safety Alert 14-25, for example, covers those hazards that are linked to li-ion batteries and urges the importance of proper inspection regimes and crew training.
Additionally, there are practical, common sense steps that should be taken. Make sure that li-ion batteries are certified to UL, CE or IEC standards. At all costs, avoid cheaper products, such as chargers, and stick to the manufacturer’s specifications always.
Mixing battery types must be avoided. Compatibility between batteries, devices and chargers must be verified to avoid electrical mismatches that could cause overheating or failure. For shipboard use, all procurement should be documented in inventory logs to ensure traceability and accountability
Storage Consideration
Li-ion batteries do not like excessive heat or cold and must be stored in cool, dry, well-ventilated areas. Li- ion fireproof containers and special bags should be used where possible and kept well away from flammable materials. Crew should avoid stacking batteries, which can cause short circuits and fires, and ensure that personal devices and power banks are stored separately from combustible items.
Some practical safety tips and advice
- Any li-ion battery propulsion installation should have been installed by a competent person. Are you able to check this is the case? And does it meet the ISO 23625:2025 Small craft – Lithium-ion batteries standard published last year? This document specifies requirements and recommendations for the selection and installation of li-ion batteries for boats, as well as requirements for the safety information provided by the manufacturer.
- It is recommended that devices should never be left on charge overnight unattended. Even when charging in the daytime, it is good practice to be able to have line of sight to your device on charge.
- Checking batteries regularly is a good and sensible practice. Look for any signs of swelling, corrosion or weeping. If you see something that looks wrong, be vigilant as the device could misbehave without warning. Isolate it in a secure place if it is safe to do so.
- Never accept a charger offered by someone else because you have left yours behind. You cannot vouch for its authenticity.
- Buy replacement batteries or chargers from trusted suppliers, and always choose a genuine, branded product.
- Never cover chargers and make sure they are charged in a well- ventilated area.
- Always charge in cool, open areas and avoid charging in direct sunlight or hot environments.
- Never charge a li-ion battery device in a place where you would need an escape route in the event of a fire – the speed and rapid spreading of any fire could block your way out.
- If you see white vapour that may look like smoke coming from a battery then get out, stay out and call the fire service immediately.
In conclusion
Having some knowledge about li-ion battery technology and its associated risks, (much of which is simply common-sense), can surely only be a good thing in both our personal and professional lives. You are encouraged to share some of what is now known about li-ion battery fires with your own networks.
By Mike Schwarz, Chief Executive Oficer, International Institute of Marine Surveying