Lithium Battery Fires and Superyachts: An Emerging Safety Issue

With superyachts increasingly carrying an array of toys such as electric scooters, bikes, seabobs, and jet skis on board, a new safety issue is emerging; lithium-ion battery fires. To date, superyacht owners and operators have been unaware of the hazards and consequences of lithium-ion battery failures. To raise awareness of this important safety issue, Brookes Bell and Wilsonhalligan offer an overview of the situation below.


How big is the issue?

Are lithium-ion battery failures as big an issue as the other safety issues facing superyacht owners and operators? The answer is “Yes”, and it is set to become a bigger issue as more and more consumer goods (laptops, smartphones) and toys (jet skis, scooters) that are regularly found on board yachts make use of lithium-ion batteries.

Even superyachts themselves are beginning to incorporate lithium-ion batteries into their propulsion systems and for powering auxiliary machinery. It is not an issue confined to superyachts either. Consider the Felicity Ace – this cargo ship burned continuously for nearly two weeks before eventually sinking. The vessel had been transporting nearly 4,000 luxury vehicles from manufacturers including Porsche, Audi, Lamborghini, and Bentley. Among the cars on board were a number of fully electric models, such as the Volkswagen ID.4 and Audi e-tron. Reports from the scene suggest that the fire started in the hold and may have originated from a lithium-ion battery in one of the electric vehicles.

Aside from the Felicity Ace incident, this year has seen a spate of superyacht fires – many of which could potentially have resulted from lithium-ion battery failures in devices and toys on board.


How serious are lithium-ion battery fires, and what do they involve?

Superyacht owners and operators are undoubtedly familiar with the dangers of fires related to faults in switchboards, main machinery, or as a result of poor housekeeping etc. However, it is of the utmost importance that they familiarise themselves with the complex and catastrophic dangers offered by lithium-ion battery fires. Put simply, lithium-ion battery fires are quite unlike other fires superyacht operators are likely to have encountered before – and therein lies their danger. When a lithium-ion battery fails, the speed of failure (seconds), production of significant quantities of toxic, corrosive and flammable gases (000’s of litres), as well as the rapid development of intense heat (+450ºC) and explosive situations can result in devastating situations.

Remember, it is not just smoke that you are breathing in. These gases are likely to be harmful to health and you should avoid entering any area with a battery failure without using the appropriate respiratory and protective equipment. Whilst lithium-ion batteries are a great technology that allows for the storage of large amounts of energy in small spaces, and with high energy densities, they presently have numerous safety concerns.

The risks presented by lithium-ion batteries can be categorised into three types:

  • Mechanical – external local damage to the lithium-ion battery such as impact, indentation, or punctures etc.
  • Electrical – overcharging or over-discharging the battery.
  • Thermal abuse – subjecting batteries to extreme temperatures.

Whatever the cause of failure, it can be a small or large event and happen over time or in milliseconds with dramatic, explosive and devastating consequences. Once failure starts, it can lead to thermal runaway. Thermal runaway is a reaction where the heat generated from the failure of the lithium-ion battery reaches a stage where it becomes self-sustaining. Once ongoing, it is very difficult to stop and results in battery temperatures rising exponentially. When a lithium-ion battery goes into thermal runaway, it can result in explosion, fire, and/or release of smoke and gases.

These gases can include hydrogen fluoride and related fluoride gases, which have been identified as a major toxic and corrosive hazard (e.g., hydrogen fluoride becomes hydrofluoric acid in water). Lithium-ion battery fires also burn for long periods and can reignite hours, days, or even weeks later; this can occur multiple times. In short, lithium-ion battery fires are much harder to extinguish than fires from traditional internal combustion engines, for example.

The risk presented by lithium-ion battery fires is one that cannot, and should not, be ignored by superyacht owners and operators.


Lithium-ion battery fires and insurers

Lithium-ion battery fires are also posing a challenge to insurers. In fact, such is the controversy surrounding lithium-ion batteries that some insurers are now refusing to insure superyachts that make use of, or carry devices and/or toys that make use of lithium-ion batteries.

Other insurers are asking owners to agree to clauses whereby they are responsible for 50% of any loss due to the misbehaviour of lithium-ion batteries. With there being an increasing push to electrify the maritime industry, we’re likely to see far more superyachts being retrofitted with propulsion systems that in some way incorporate lithium-ion batteries. This may be good news for the environment, but it makes fire mitigation efforts more important than ever for superyacht insurers, owners, and operators alike.


Fire mitigation for lithium-ion batteries

At Brookes Bell, we have been closely following the occurrence of lithium-ion battery fires as an emergent threat to superyachts, and other marine vessels for that matter. As we recently set out in a joint white paper on the issue, lithium-ion battery fires pose a unique and complex challenge – and thus equally distinct fire mitigation measures are required.

It may well be that a combination of measures are required to bring a lithium-ion battery fire under control. Such methods, together with potentially updated and improved monitoring systems and equipment need to be urgently considered.

Examples of these include:

  • Improved automatic fire detection alarm systems.
  • Fire blankets.
  • Appropriate and upgraded personal protective equipment (PPE).
  • Provision of hand-held thermal imagery equipment for use by shore as well as shipboard personnel.
  • Review of statutory regulations (HSE, SOLAS & STCW) and standards.
  • Additional specific, shore-based, practical training for ship and shore-based staff.

The full set of recommendations can be viewed in the white paper.


Risk prevention for lithium-ion batteries

In addition to new and enhanced methods and monitoring systems, there are a series of risk prevention measures that superyacht owners and operators can introduce to prevent lithium-ion battery fires from occurring in the first place.

Basic prevention measures should include:

  • Monitoring when and where devices and batteries are charged, ensuring they are on hard surfaces and ideally not charged overnight and left unattended.
  • Preferably charging electric toys outside of accommodation or workplaces. For example, seabobs, bicycles and scooters. The priority is to ensure an incident does not affect the ability to exit and escape any spaces, should a battery failure incident occur.
  • Avoiding storing or charging at very low or very high temperatures. Always allow for ventilation in hot environments and do not leave in direct sunlight.
  • Avoiding leaving on a continuous charge when a device is not in use.
  • Never covering batteries, chargers or charging devices whilst they are plugged in and charging.
  • Protecting batteries from being mechanically damaged, as far as possible.
  • Preferably sourcing branded, genuine battery replacements from reputable suppliers, if required. Copies or generic chargers, charging cables and batteries may look the part but may not have the appropriate safety mechanisms built in.


Brookes Bell: the specialists at superyacht fire mitigation

Brookes Bell has a team of superyacht experts with extensive experience of carrying out fire risk analyses on a range of superyachts, providing recommendations on risk mitigation measures that will keep your vessel safe from fires and explosions.

In addition to risk analyses, Brookes Bell is able to conduct maritime fire and escape simulation analyses, modelling how a fire could spread through a vessel – this is ideal for superyachts at design stage – you should not wait until your superyacht is built to be proactive with fire safety.