The batteries that caused the explosion of Hezbollah's radios

It is still not clear what caused the mysterious explosion of the Hizbullah radios, but the main explanation at the moment in the unfolding case is that it was some kind of ignition, possibly of the batteries. Our digital world relies heavily on rechargeable and regular batteries to power a huge variety of electrical devices, from walkie-talkies to mobile phones, laptops and electric vehicles. However, alongside the advantages of these technologies, there is a significant risk of catching fire or even explosion of certain batteries, especially in difficult conditions of use or in cases of technical malfunctions.

These are the main types of batteries in use today:

Alkaline batteries - these are disposable batteries common in small devices such as remote controls and toys. They do not tend to catch fire or explode dangerously, although in rare cases they may leak chemicals.

NiCd batteries - older rechargeable batteries, which were once common in devices such as old walkie-talkies, power drills and cordless devices. These batteries offer good performance, but can catch fire if overcharged or overheated.

Nickel-metal-NiMH batteries - these are more modern rechargeable batteries than the NiCd and are used in a variety of devices, such as digital cameras, electric toys and even in modern radios. They are less susceptible to ignition than lithium-ion batteries, but can still overheat under heavy loads or overcharging.

Li-ion batteries - these are the most common rechargeable batteries today and are used in many devices, such as smart phones, laptops, drones and electric vehicles. Despite their high performance, lithium-ion batteries are known to be more sensitive to heat conditions and physical damage, which can lead to ignition and even explosion in some cases.

Lithium-polymer batteries (Li-Po) - another type of lithium battery, common in thin devices such as smart phones, drones and laptops. These batteries are lighter and thinner, but they are also more sensitive to mechanical damage and improper charging, which can cause a fire.

Flaming or exploding batteries are rare phenomena, but they do occur in cases of serious technical problems or improper use. Some of the common reasons for this include:

Overcharging: When a battery is charged beyond its maximum capacity, a chemical reaction can occur that releases heat, which can lead to a fire.

Rapid discharge or overload: In cases of high load use, such as while operating a heavy device, the battery may overheat, which increases the risk of catching fire.

Physical damage: Lithium batteries, especially lithium-ion and lithium-polymer, are very sensitive to physical damage such as impacts, falls or punctures. In such cases, internal cells in the battery may break down and create an internal short that leads to rapid ignition.

High temperature: Batteries, especially lithium-ion, are sensitive to use in extreme heat conditions. High external temperatures or continuous heating of the device may cause the battery to overheat, leading to a fire.

During use, rechargeable batteries can reach very high temperatures. For example, a lithium-ion battery can heat up to a temperature of 60-70 degrees Celsius in cases of heavy use or prolonged charging. When the battery is damaged or overcharged, it may go through a process called thermal runaway in which the heat generated inside it continues to raise the temperature uncontrollably, which can cause an explosion or sudden ignition.

As you know, one of the prominent areas where cases of battery fires have been recorded is the world of electric bicycles. Such events have also occurred in Israel in recent years, in some cases extensive damage was caused to the room where the fire occurred. 

Lithium-ion batteries, which are used as the energy source in electric bicycles, can catch fire mainly during charging. The mechanism that causes this is related to overloading, excessive heating, or internal damage to the battery's chemical cells. When the battery is overcharged, a process called "thermal runaway" may begin, in which the heat generated causes an acceleration of internal chemical reactions until ignition or explosion.

Most of the time, in order to avoid battery fires, it is recommended to use only original and high-quality chargers adapted to the type of battery, to avoid leaving the battery in a prolonged charge beyond the required time, and to store the battery in a cool and well-ventilated place. Meanwhile, the manufacturers recommend making sure that the battery is not exposed to physical damage or extreme heat, which may cause internal damage and increase the risk of catching fire.