Lithium-Ion Batteries on Boats: Everything You Need to Know

These days, we have lithium-ion batteries in almost everything. They're in your phone, they're in your computer, and they might even be in your boat.

That's because lithium-ion batteries are a marked improvement over older electrochemical technologies, and they're extremely suitable for portable electronics and electric vehicles. Generally, they're cheap, they're versatile, and they're relatively reliable, but there are some important drawbacks and risks associated with them that every boat owner should be aware of.

If you have an electric or hybrid boat that utilises lithium-ion batteries, it's especially important for you to be aware of how they work, how they can break, and how to stay safe on your vessel. Even if you have a traditional vehicle, you can benefit from learning about lithium-ion batteries because you'll likely have mobile devices and other electronics onboard that contain these powerful, yet dangerous materials.

So how exactly do lithium-ion batteries work? And how can you stay safe when using them?

Types of Battery Chemistry

Let’s start with a brief chemistry lesson.

All batteries exist as a form of temporary power storage. Batteries are designed to store chemical energy and then convert that chemical energy into more useful electrical energy, through the processes of electrochemical reactions. Typically, this is done with electrochemical cells, each of which contains three components:

1. An anode, or negative electrode.
2. A cathode, or positive electrode.
3. An electrolyte, or substance through which electrons can travel.

Generally, the negatively charged anode contains electrons, which can be produced and transmitted to the cathode through the electrolyte. This differential, properly harnessed, creates a steady flow of electrons from the anode to the cathode, and this flow of electrons makes up the electricity we need to operate everything from wireless earbuds to, well, boats.

Traditionally, batteries were lead-acid batteries; although these are sometimes used today, they’ve become somewhat outclassed. Originally emerging in 1859, lead-acid batteries use lead-based electrodes and sulfuric acid as the electrolyte between them. Historically, lead-acid batteries have been reliable, cost-effective, and capable of delivering high surge currents. Today, they’re still used in automobiles, and as power backups, but people are exercising more caution because their lead and sulfuric acid content have significant environmental drawbacks.

Rechargeable batteries are much more convenient than traditional batteries, but they also have different chemical needs; this is where nickel-cadmium batteries came in. Nickel-cadmium batteries, as the name suggests, utilises both nickel and cadmium. The cathode is typically nickel oxide hydroxide, the anode is cadmium, and the electrolyte is typically potassium hydroxide. Gradually, the nickel oxide hydroxide is reduced to nickel hydroxide as the battery is discharged. They can be charged again by supplying the nickel hydroxide with more electrons.

Nickel-cadmium batteries were known to be durable and capable of great performance, but they have a big problem: the memory effect. In the memory effect, the battery “remembers” its history of discharge, eventually reducing its maximum energy capacity. On top of that, cadmium is a toxic heavy metal that can be detrimental to the environment.

Nickel-metal hybrid batteries attempted to introduce an improvement to this system, using a hydrogen-absorbing alloy as the anode, replacing the detrimental cadmium. These were the earliest batteries used in electric and hybrid vehicles, but they’ve largely been replaced by the main topic of this article: lithium-ion batteries.

Lithium-ion batteries come in many varieties, as there are multiple types of viable lithium-ion chemistries, each of which has distinctive strengths and weaknesses. Some of the most common are lithium cobalt oxide (LCO), lithium manganese oxide (LMO), lithium nickel manganese cobalt oxide (NMC), lithium iron phosphate (LFP), and lithium nickel cobalt aluminium oxide (NCA). The biggest differences between them are in the selection of the cathode, which is responsible for dispersing lithium ions during charging and discharging. Most of the time, the anode is simple graphite.

In all lithium-ion batteries, lithium ions are moved from the anode to the cathode (during discharge), through an electrolyte – just like batteries in the past. However, both electrodes can facilitate movement into and out of their systems because of a process known as intercalation. In charging, the direction of the flow of electrons is reversed.

Lithium-ion batteries are very high energy density, with long lifespans, no “memory” problem, and slow charge loss, so they’ve become dominant in the world of batteries and electronics. They are unquestionably the leading type of battery for mobile devices, computers, and electric and hybrid vehicles.

However, lithium-ion batteries aren’t perfect.

How Lithium-Ion Batteries Fail

Lithium-ion batteries can fail in a number of ways, and when they do fail, the results are sometimes spectacularly dangerous. If overheated, if physically damaged, if overcharged, or if manufactured with a defect, a lithium-ion battery can erupt into thermal runaway and start catastrophic fires.

• Thermal issues. Lithium-ion batteries are very sensitive to high temperatures, and even a small amount of overheating can trigger the development of thermal runaway. Essentially, the extra heat triggers a series of chemical reactions within the battery, each of which generates more heat, leading to an explosion of exponential increase in temperature. Once this process begins, it's very hard to stop, and it will likely cause the battery to catch fire or explode. As you can imagine, this is a horrible scenario if you're trapped on a boat. Fortunately, this is also a relatively easy issue to avoid. It's important to make sure you never use lithium-ion batteries at extremely high temperatures, and you should avoid overcharging them as well, as charging beyond capacity can lead to excessive heat buildup. Faulty chargers and short circuits can also generate local heat, causing the runaway thermal effect. Fortunately, recent lithium-ion battery producers have begun to build in fail safes to mitigate many of these issues.
• Mechanical issues. Physical stress and mechanical issues can also cause problems in lithium-ion batteries. If you cause internal components to break or short circuit, it can lead to a series of chemical reactions that result in the same thermal runaway effect. This could include dropping or crushing a battery or even mishandling the battery. Punctures and pierces are especially devastating to lithium-ion batteries, so you should take care to physically protect them.
• Internal failures. It's also possible for a lithium-ion battery to fail because of problematic internal components. If the battery is designed or manufactured poorly, or if there are issues with impure or contaminated raw materials, it can spontaneously combust.

In short, lithium-ion batteries can fail in quite a dramatic and unexpected fashion, and it's important to be cognisant of these risks so you can mitigate them when possible. Although a reasonably prudent person can avoid catastrophes linked to thermal issues and mechanical issues, manufacturing defects are a bit harder to avoid.

Safety Systems for Lithium-Ion Batteries on Boats

If you have lithium-ion batteries on your boat, you should be prepared to take a few additional safety precautions to keep yourself and everyone on board protected from potential issues.

• Professional installation. First, you should always make sure that your lithium-ion batteries are installed and maintained by trained professionals. There's a lot that can go wrong in the installation process, especially if you're not familiar with the chemistry and mechanics of lithium-ion batteries, so you're better off leaving these in the hands of pros.
• Manufacturer research. It's also a good idea to research the manufacturer responsible for designing and producing your particular lithium-ion batteries. If there are known flaws or defects associated with their products, you should be extra cautious, or consider replacing these batteries with newer ones. Because manufacturer defects represent only a small portion of lithium-ion battery failures, keep in mind that this is only one aspect of your defence.
• Protection from heat. Overheating is a very common cause of lithium-ion battery failure, so it's a good idea to keep your batteries protected from the heat however you can. That means keeping your batteries out of the sun, shielding them from major sources of heat, and checking them regularly to make sure they aren't getting too hot.
• Protection from punctures and crushing. In most electric and hybrid boats, lithium-ion batteries are naturally encased to protect them from punctures and crushing. However, it might be prudent to double check these security measures to ensure that no mechanical issues can affect your batteries. Even a single piercing or mechanical incident can wreak havoc on your boat.
• Overcharging prevention. Again, most manufacturers design and build lithium-ion batteries with deliberate and concentrated efforts to prevent the possibility of overcharging. Even so, it's important for you to take precautions to prevent overcharging independently. Make sure you're charging up your battery exactly as your manufacturer instructed, using only appropriate cables and appropriate timing.
• Fire detection and suppression. Even with all the right precautions in place, a lithium-ion battery failure is still possible, and so is a lithium ion battery fire. Such a powerful chemical fire is a significant risk on a yacht, when you might be miles away from shore. Accordingly, you need to have fire detection and suppression methods available on board, including a fire extinguisher that can handle chemical fires. Unfortunately, even powerful fire extinguishers may not be enough to control the fires resulting from these battery incidents.
• Routine maintenance. Sometimes, a lithium-ion battery will show signs of early failure long before it erupts in flames. It may make strange noises, it may begin to warp, and it may otherwise look or seem abnormal. You don't have to be a battery expert to occasionally check on your lithium-ion batteries and determine whether aberrant activity is occurring. If you notice anything strange with your lithium-ion batteries, avoid going out on the boat and contact a professional right away.
• Crew education. Also, it's important to educate and train your crew about the dangers of lithium-ion batteries and the proper precautions for mitigating risks associated with them. If everyone is on the lookout, and everyone is aware, you'll be much more likely to prevent a disaster and step in effectively if one occurs.
• Insurance. Double check your insurance policy to make sure that your boat is protected in the event of a fire. If a lithium-ion battery incident occurs, you'll at least be able to collect the money to replace it.
• Escape routes and emergency response plans. Take the time to plan some escape routes and your response in case of an emergency. You and everyone on board should know exactly what to do if a fire breaks out unexpectedly or if there are other issues associated with your batteries.
• Recycling. Although lithium-ion batteries are arguably a step up from their predecessors in terms of environmental impact, it's still irresponsible to dispose of them improperly. Always make sure to properly recycle your lithium-ion batteries when disposing of them.

Lithium-ion batteries are a marvel of modern technology, but they also have some drawbacks that you need to be aware of as a boat owner.

If you're interested in an electric, hybrid, or even a traditional boat, we've probably got what you're looking for. You can start browsing our massive selection of new and used yachts for sale today, or list one of your own for sale – either way, we’re here to help!