All these personal electronic devices are powered by lithium batteries All these personal electronic devices are powered by lithium batteries Never leave your mobile phone on charge all night Never leave your mobile phone on charge all night The last place you want a lithium battery fire is in the confined space of a passenger aircraft The last place you want a lithium battery fire is in the confined space of a passenger aircraft A pilot with an AvSax lithium battery fire mitigation bag A pilot with an AvSax lithium battery fire mitigation bag

The essential guide to lithium battery safety … and how we are all breaking the rules

Lithium batteries power all our essential devices from mobile phones to laptops … but just about everyone is breaking essential safety rules and potentially putting themselves and others in danger.

Golden rules include never leaving mobile phones or other personal electronic devices on charge overnight and never charge them on soft furnishings such as beds or settees as they could easily catch fire if the device overheats.

Yet millions of people worldwide are ignoring these rules so fires caused by lithium batteries are happening far too regularly. The number will continue going up as the global demand for lithium batteries is growing by almost a third every year.

No figures are collated nationally but London Fire Brigade has revealed it attends 24 fires every week started by chargers, batteries and cables. That must mean there are tens of thousands of fires across the UK started by products linked to lithium-ion batteries every year.

London’s firefighters are in no doubt about the main culprit sparking lithium battery fires, stating: “Counterfeit electrical chargers can be deadly. Many fail to meet UK safety regulations leading to fires and injury. What may seem like a bargain isn’t worth the risk when you consider that it could cost a family member’s life.”

Around half of all fires in recycling depots in the UK are caused by lithium battery fires being thrown into household rubbish instead of being taken to battery collection points – you’ll see them in many supermarkets.

The problem is worldwide. In Newy York alone, lithium battery fires have caused 60 fires in the city in the first four months of 2022, causing five deaths and 66 injuries. There were just 18 fires for the same period in 2021.

Firefighters in New Zealand have tackled 35 house fires caused by batteries so far this year.  

Planes are especially vulnerable to lithium battery fires as the last place you’d want a fire giving off toxic smoke is in the confined space of a passenger aircraft. More than 80 airlines worldwide carry AvSax lithium battery fire mitigation bags that use liquid inside them to keep the overheating battery cool.

AvSax, which won the prestigious Queen’s Award for Enterprise in the UK, are also known as ‘burn bags’ and are now on more than 15,373 aircraft worldwide and have been used 33 times to deal with emergencies since the start of 2017. Every time they have been deployed the aircraft has been able to complete its journey safely with no need to divert or make an emergency landing.

When lithium batteries overheat they go into what’s called thermal runaway – a rapid and uncontrolled chemical reaction which burns at exceptionally high temperatures. When one cell in a battery overheats it can produce enough heat - up to 900°C (1652°F) - to make adjacent cells overheat too even to the point where the battery shoots flame out or even explodes.

So here’s the essential guide to keeping lithium batteries safe and the personal electronic devices we are talking about include mobile phones, tablets, iPads, e-cigarettes, laptops and headphones.


  • Charge any devices under a pillow, on a bed or on a couch – if they overheat they could easily spark a serious fire.
  • Use or charge a battery that shows signs of swelling, overheating or any other form of damage.
  • Leave them on charge after they have charged up – especially overnight. If they do overheat and catch fire you’ll be unaware what’s happening and a serious fire could quickly take hold.
  • Leave devices in direct sunlight, hot vehicles or anywhere they are likely to overheat.
  • Overload sockets.
  • If the personal electronic device is crushed or punctured it could trigger thermal runaway and a fire.
  • Dispose of lithium-ion batteries in general rubbish.
  • Leave discarded batteries in piles.


  • Only use the battery and charger that are designed for the device – don’t be tempted to buy a cheap alternative on the internet or even down at your local market as it’s probably not manufactured to industry safety standards.
  • Store and charge devices on non-flammable surfaces such as kitchen work surfaces.
  • Dispose of lithium-ion batteries in specialist recycling containers – you’ll find them in many supermarkets.
  • When travelling on aircraft carry all your personal electronic devices and lithium batteries in hand luggage. Don’t put them in the luggage hold. If they catch fire the fire suppression systems on aircraft can’t cope with the intense heat of a lithium battery fire. If they are in the passenger compartment the cabin crew can deal with the problem using lithium battery fire containment bags such as AvSax.