Backup Batteries: Potential Hazards and Tips for Preventing Fire and Explosions

Fire and explosion incidents involving power banks have increasingly raised concerns about safety, leading many to ask: Why can power banks catch fire? Why are they banned from checked baggage? And most importantly, what should users do to ensure safety when using them?

This article will analyze in depth the dangers of backup batteries and provide effective preventive measures to help you use this device in the safest way.

Why are backup batteries at risk of explosion?

Lithium-ion (Li-ion) batteries, first developed in the 1970s, have become extremely popular due to their ability to store large amounts of energy in a more compact and lightweight design than nickel-metal hydride or lead-acid batteries.

Today, these batteries power a wide range of devices, from smartphones and power banks to electric cars and even the International Space Station.

However, Li-ion batteries have a worrying drawback: they are highly flammable. Their mechanism for storing and releasing electrical energy is based on electrochemical reactions, which generate heat.

Under extreme conditions such as extremely low (below 0°C) or high (above 65°C) temperatures, mechanical stress or rapid charging, the battery may become overheated and unstable.

A key element in preventing short circuits in Li-ion batteries is the separator between the positive (cathode) and negative (anode) electrodes. This component is usually made of a microporous polymer material and acts as a barrier, preventing the electrodes from coming into direct contact with each other.

However, to optimize charging speed and extend the service life, manufacturers often reduce the thickness of this separator. When the battery is charged, the electrodes tend to expand, creating mechanical stress on the separator. If the separator is too thin, the risk of cracking increases, leading to the electrodes coming into contact with each other, causing a short circuit.

As a result, the temperature inside the battery increases rapidly, which can melt the separator, leading to a more serious short circuit. This in turn causes smoke, fire, and even explosion.

While thicker separators may improve safety, they increase internal resistance in the battery, making charging slower.

Additionally, thick separators take up a lot of space, reducing energy storage capacity. So in the race to create fast-charging batteries, it is an unfortunate truth that safety is often sacrificed.

Not only design, errors in the manufacturing process can also make batteries less safe, increasing the risk of unexpected incidents.

Should users be worried?

Technology experts estimate the odds of a mobile device exploding are just five in a million. However, recent recalls and fires involving faulty batteries have been on the rise, raising concerns about battery safety.

In 2022, the Singapore Consumer Product Safety Office (CPSO) ordered Harvey Norman Singapore to stop selling the Urban.Power N.Brandz PD18W 10000mAh power bank and forced online retailer TMALL1688 to stop distributing the 20,000mAh portable power bank, after both products caught fire during safety testing.

Not only backup batteries, other electronic devices are also constantly being recalled due to the risk of overheating. In October 2020, manufacturer LG Electronics had to replace the power board on 18 OLED TV models manufactured from 2016 to 2019 for free due to the risk of overheating that could lead to fire.

Previously, in 2018, CPSO discovered 17 models of power banks catching fire during testing and quickly issued a warning, requiring retailers to stop distribution.

The world's biggest mobile phone recall took place in 2016, when Samsung was forced to recall 2.5 million Galaxy Note7s due to battery overheating, leading to fires and explosions.

Not only phones or power banks, personal mobile devices are also constantly the cause of fires.

December 2022: A fire that destroyed a one-room flat in Woodlands (Singapore) was started by a personal mobility device with expired batteries, purchased online.

April 2022: An apartment in Bukit Merah (Singapore) caught fire after an electric bicycle battery exploded while charging.

In 2021 alone, there were 32 fires involving personal mobility devices and 23 caused by power-assisted bicycles in Singapore.

The increase in these incidents shows that the risk of fire and explosion from faulty batteries is an increasingly serious problem, requiring tighter control from both manufacturers and consumers.

Users shouldWhat to do to prevent fire risk?

Since there is no way to accurately determine whether a battery is safe or faulty, users should limit charging their devices overnight to reduce the risk of overheating.

In addition, when charging for a long time, it is necessary to ensure that the area around the extension socket is always neat, avoid tangling or being pinched, causing the risk of fire. It is best to always use genuine charging cables to ensure safety and best performance for the device.

Avoid mechanical impact, such as when the phone or power bank is dropped, which may damage the internal structure of the battery, leading to short circuit and overheating.

One telltale sign of a damaged battery is swelling. If you notice a swollen battery, you should stop using it immediately, replace the battery, or dispose of the device properly.

Also, check the battery for signs of corrosion or white powdery residue, as these are signs of damage.

To prolong the life of Li-ion batteries, store them in a dry, well-ventilated place, away from direct sunlight or high heat sources. When storing, batteries should be stacked neatly, avoiding impact or breakage, and ensuring that there are no sharp objects that can cause damage.

Users should buy spare batteries from reputable sources and use genuine batteries, avoid buying used batteries because it is impossible to accurately determine the condition or remaining life of the battery.

Typically, Li-ion battery life ranges from 2 - 3 years, equivalent to 300 - 500 charge cycles, after which the battery performance will gradually decrease and there is a higher risk of safety loss.

In short, power banks are a useful tool in modern life, but if not used and stored properly, they can become a potential hazard, causing serious fires and explosions.

Incidents involving Li-ion batteries in electronic devices, from phones and laptops to electric vehicles, have shown the importance of understanding how they work, following safety measures and choosing quality products.

The convenience of power banks only really comes into play when they are used responsibly. Therefore, every consumer needs to equip themselves with the right knowledge, choose products from reputable manufacturers and comply with safety principles, in order to protect themselves and those around them from unnecessary risks.