Understanding Lithium-Ion Batteries: uses, risks, and safety precautions

LiBs, along with their battery management systems like cords and chargers, are the most common type of rechargeable battery. They’re widely used in many portable electronics and electric transportation devices.

These are different to the ‘single use’ lithium batteries found in most television and audio system remote controls, garage door and home alarm remotes, and home smoke detectors.

Here are some examples of where you can find LiBs:

• Communications: Such as laptops, tablets, mobile phones, cameras, and portable power banks.
• Leisure: Such as golf buggies and carts, drones, model aircraft, remote-control cars, children's ride-on cars, gaming consoles, cameras, action cams, headphones, and massage devices.
• Mobility: Such as e-bikes, e-scooters, e-skateboards, electric wheelchairs, mobility scooters, and electric vehicles (EVs) including buses and other transport.
• Gardening: Such as lawn mowers, whipper snippers, blowers, and hedgers.
• Trade and handy work: Such as drills, rattle guns, and other power tools.
• Household: Such as cordless vacuum cleaners, torches, home solar battery energy storage systems, and e-cigarettes

LiBs, their cords, and their chargers can pose a potential fire and explosion risk if they fail to operate as designed. This can lead to significant property damage and serious injury to people.

LiBs can fail for several reasons, including when they’re damaged from:

• Abuse: Such as impact, crushing, overheating, or submersion
• Over charging
• Whilst in transit or in storage
• Poor manufacturing: ie. defective
• Poor quality: ie. cheaply made

According to an article from EV fire safe, the starting point for all LiB fires is thermal runaway: an unstable chemical reaction.

When a battery cell is abused, it can short circuit. This means the positive (anode) and negative (cathode) parts touch. This causes the cell structure to break down and produce a lot of heat quickly.

The heat inside the cell builds until the pressure becomes too much. This causes the cell to pop and vent out heavy metals and gases. This appears as a dark, then lighter, cloud of vapor.

This vapor cloud contains a mix of toxic and flammable gases, mainly hydrogens. Many of these gases can cause respiratory distress or suffocation.

When one cell starts to heat up and release gases, others in the pack will follow in a domino effect. This is thermal runaway. Once it starts, it's difficult for emergency responders to stop it.

A lot of attention has been drawn to the risk of thermal runaway, particularly in EV’s. However, according to the EV Fire Safe Battery Fire Risk Matrix the risk of fire from road registered EV’s is very low. They’re subject to stringent regulations and high-quality battery management systems. They’re less likely to catch fire than personal mobility devices (PMDs) such as eScooters and eBikes. These generally use lower-quality batteries, are less regulated, and therefore have a higher risk of fire.

Understanding how LiB fires can occur can be important in helping prevent them.

Here are some of the hazards:

• Leaving a device on charge after it has fully recharged
• Charging whilst unattended or unsupervised: For example, while asleep or away for long periods of time
• The device, battery, charger or cords being positioned in, or covered by flammable material: For example, bedding and clothing
• Purchasing second-hand devices: Such as power tools. This is because the history of battery use may not be known.
• Using a battery that has been damaged or appears broken
• Continued use of a lithium-ion battery after it has been dropped many times
• Using cheap third-party chargers or cables: I.e. not the originals from the supplier

Warning signs that a LiB may fail

• The device is bulging or cracking
• The device is overheating
• Vapours appearing
• Popping sounds: I.e. like gunshots

Before you start charging any batteries, make sure you have working smoke alarms or heat alarms in the rooms where you store or charge them.

It's also important to charge batteries on surfaces that can't catch fire, like concrete floors or tiles. Avoid charging them on beds, couches, or carpets.

For larger batteries, such as those used in e-scooters, e-bikes, and power tools, it's best to charge them in a garage, shed, or carport. Keep these away from living spaces and exits.

Never charge batteries when you’re asleep or not home. Once your device is fully charged, disconnect it from the charger.

Avoid using and charging devices in bed, especially items like phones, tablets, and vapes. These devices can overheat and catch fire when left on blankets, sheets, or clothing.

If a battery is swelling, bulging, leaking, or overheating, don’t use or charge it. Also, avoid using and charging cracked, dented, punctured, or crushed devices.

Always use the charger that came with your device or battery. If you need a replacement, make sure it’s an approved charger.

Just because a plug fits, doesn't mean it's safe to use. Always look for chargers with the Australian Regulatory Compliance Mark Tick. Using the wrong charger can damage the battery and cause it to overheat, which can lead to a fire.

If charging a lithium-ion battery in your home leads to a fire causing property damage or injury, and you’re found liable, your Buildings and Contents policy can help pay for the associated legal liabilities and compensation. Terms, conditions, limits and exclusions can be found in your PDS.