Managing risk from lithium-ion batteries

The use of lithium-ion batteries is on the rise. They power all kinds of portable devices, and larger batteries are essential for powering electric vehicles, bikes, scooters and forklifts. As we become more reliant on lithium-ion powered devices, and as more of us switch to electric vehicles, business owners need to aware of the risks these batteries can pose. These risks are growing – in the UK, fires related to lithium-ion batteries have quadrupled since 2020, killing eight people and injuring a further 190.

In this article, we look at what makes lithium-ion batteries potentially dangerous, and ways of managing the risk to your business.

What are lithium-ion batteries?

Lithium-ion batteries – also known as li-ion batteries – are a common type of rechargeable battery. They are used to power everything from electric cars to smartphones, laptops and other portable devices. They are widely used as, compared to other battery types, they are lightweight, have a high energy density and a long lifecycle.

Lithium-ion batteries are not the same as lithium batteries. Ordinary lithium batteries are used in items such as wristwatches, smoke detectors, and TV remote controls.

By contrast, lithium-ion batteries are rechargeable and can be found in many of the products below.

Where are lithium-ion batteries found?

Because lithium-ion batteries are lightweight, rechargeable and have a long lifecycle, they are used in a huge number of applications. They can be found in almost every workplace and home.

Below are just some of items lithium-ion batteries are used for.

Consumer electronics. Lithium-ion batteries power all kinds of consumer electronics, including smartphones, tablets, laptops, smartwatches, e-cigarettes, cameras and portable power banks.
Tools. Many tools are powered by li-ion batteries, including cordless drills, saws, sanders and nail guns.
Vehicles. Lithium-ion batteries are used in electric cars, bicycles, scooters, motorcycles, trucks and buses. They are also used to power electric boats and yachts.
Energy storage. Lithium-ion batteries are used to store energy from solar panels in home energy storage systems. They are also used in uninterruptable power supplies (UPS) for critical systems and portable generators.
Medical devices. These batteries are used in portable medical equipment, such as defibrillators, implantable devices, and certain pacemakers.
Industrial equipment. Lithium-ion batteries are increasingly used in industrial contexts. For example, they are used to power forklift trucks and industrial robots.

Aside from these examples, li-ion batteries can be found in many specialist applications, ranging from drones and portable military equipment to satellites.

Why do lithium-ion batteries catch fire?

When a lithium-ion battery generates more heat than it can safely disperse, this can lead to a phenomenon called ‘thermal runaway’. This rapid release of heat energy can lead to a fire or explosion.

Thermal runaway can occur in a variety of situations. These include:

An internal short circuit. This can be caused by manufacturing defects, impact damage or a puncture to the battery.
Overcharging. If a battery is charged beyond the capacity it was designed for, excessive heat generation can lead to thermal runaway. This can happen if you use a faulty charger, a charger not provided by the manufacturer, or a charger that’s too powerful. Some batteries have battery management systems to prevent overcharging. If these fail, the risk of fire increases.
External heat. Similarly, exposing a lithium-ion battery to excessive external heat can cause it to ignite. For example, leaving an item exposed in a car on a hot day could cause it to overheat and start a fire.
Over-discharging. If you completely drain a battery and then try to recharge it, this can lead to lithium plating forming on the anode. If this happens, it increases the risk of short circuits.
Battery degradation. As batteries age, they can degrade. Charging and re-charging a battery many times over its lifecycle can eventually lead to internal failures, leading to fires.
Improper storage. Storing batteries in high temperatures or exposing them to moisture can make failure and fire more likely.

How common are lithium battery fires?

According to the British Safety Council, there were 338 fires involving li-ion batteries in e-bikes and e-scooters in 2023. Lithium-ion batteries in domestic and business waste result in around 201 fires annually. These figures are increasing – one study suggests that, by 2025, 78 million li-ion batteries will be discarded worldwide every day, showing the increasing risk posed.

What are the warning signs of lithium-ion battery failure?

There are various warning signs that a li-ion battery is about to fail and possibly catch fire. These include:

A very hot device. Li-ion batteries generate some heat when charging, but if a battery is unusually hot to the touch, it could be defective.
A bulging or deformed battery. If a battery is bulging or changing shape, it could be overheating.
Battery making a noise. If you can hear hissing or crackling sounds, the battery is almost certainly dangerous.
An unpleasant smell. Failing li-ion batteries can emit toxic fumes.
Smoke. If a battery is smoking, a fire may have already started.

If you notice any of these signs, turn off power to the battery and – if it is safe to do so – move the device away from flammable items using an implement like tongs or a shovel. If a fire does start, call the fire service immediately.

How can businesses manage the risk?

The bigger the batteries, the more dangerous failure can be. For this reason, businesses need to consider electric vehicles as well as portable items when managing the risks they pose. Some of the key things to consider include:

Update your risk assessment. Surprisingly few businesses have updated their risk assessments to include lithium-ion batteries. A competent person needs to assess the risks associated with handling, storing, using and charging the batteries. Any assessment must comply with the Regulatory Reform (Fire Safety) Order 2005.
Buy items from reputable suppliers. Many fires have been linked to poorly manufactured li-ion batteries.
Use the correct charger. Only charge batteries using the original charger, or one with exactly the same specification.
Store batteries carefully. If batteries are not in use, store them away from heat and moisture, ideally in metal containers or fireproof bags. Keep li-ion batteries away from any flammable items.
Don’t charge batteries in unoccupied areas. Don’t leave batteries on charge overnight or unattended, and disconnect batteries when they have finished charging.
Check regularly for damage or defects. If a battery appears to be damaged, never charge it. Take it to a recycling centre so it can be properly disposed of.
Keep electric vehicles away from combustible materials and buildings. Also install automatic fire detection systems where vehicles are charged. If you have charging points (or plan to install them), your insurer will likely have requirements for where these should be located.
Do not use electric vehicles that have been damaged. If, for example, an electric car has been in an accident, assume that the battery has been damaged. Keep it away from flammable materials and get an EV recovery specialist to take it away.
Ensure the fire service knows about your charging arrangements and ask them for advice on training staff to deal with lithium-ion battery fires.

Find out more about the risks of electric vehicle fires.

Summary

Lithium-ion batteries are indispensable to modern daily life, and their use is rising. As more of us switch to electric vehicles, fires and explosions will become more common. As a result, businesses need to carefully consider and plan for the risks associated with lithium-ion batteries. It’s also essential to make sure you have the right commercial insurance.

Need help with your risk management?

For advice on managing risk and creating specific risk assessments, speak to our expert team.

Speak to us: 01603 967900

FAQs

Why are lithium battery fires hard to put out?

One major problem with lithium-ion battery fires is that the batteries generate their own oxygen when they are on fire. This can make them difficult to extinguish, requiring very large amounts of water to get them under control.

Can lithium-ion batteries catch fire when not in use?

Yes, lithium-ion batteries can catch fire when they’re not in use. For example, if they are damaged in transit or are exposed to excessive heat, they can explode or go up in flames.

What is the biggest cause of lithium-ion batteries exploding?

Nearly all li-ion fires and explosions are caused by short circuits. These can occur due to overcharging, overheating, penetration, crushing and manufacturing errors.