The expert named the most dangerous gadgets from the point of view of spontaneous combustion

We have just gotten used to the fact that we shouldn’t charge an electric scooter in an apartment – it can explode or spontaneously combust. But now there is a serious addition to the list of risk factors: fires are caused by external batteries (power banks) and powerful chargers for ordinary gadgets. In other words, ordinary accessories for the most common phones and laptops that can be found in any bag. MK found out what factors make ordinary household appliances flammable and how to protect yourself from an accident.

On April 15 of this year, an emergency occurred in one of the apartments in the 18th district of Zelenograd: the owner, according to her, put the power bank on the bed to charge and went out with the child to the kitchen. The smell of burning forced her to return; a few minutes later the bed and the device were burning brightly. No one was hurt, but the owners will have to repair not only the room (where the walls and ceiling were smoked), but also the living space of the neighbors below, which was flooded with water as a result of the fire.

This is not the first incident of this kind in the capital – for example, on April 8, a power bank exploded in a nine-story building on Uralskaya Street (VAO). Two apartments burned out and five people were injured. Exactly a year ago, in April 2023, a power bank exploded right in the backpack of a Moscow schoolgirl (the children were evacuated, but the fire was avoided). And at the end of 2022, an external battery spontaneously ignited on board an aircraft ready to take off from Domodedovo Airport: then the aircraft was not damaged, but “out of harm’s way” the airline sent passengers on a different board.

“Perhaps right now we are entering a risk zone for fires of chargers and powerful batteries,” Denis Zhelnin, owner of a digital equipment repair shop, told MK. – It’s simple: humanity always strives for more capacious batteries and maximum charging speed. This means that the magnitude of currents in charging circuits is increasing. At some point, it may happen that the circuit parameters laid down during the design of devices – roughly speaking, the width of the conductive paths and the intervals between them – will turn out to be insufficient, and the likelihood of a short circuit with all its consequences, that is, ignition, will increase.

This is exactly what happened, the engineer recalled, in 2017, when mini-tablets from one of the world’s leading manufacturers began to spontaneously combust en masse—a recall campaign followed, and air carriers even banned such gadgets from being carried on board. Now it is impossible to name a specific manufacturer with a particular risk – numerous (primarily Chinese) brands produce similar models using similar technologies.

“We can name several classes of devices with which you need to be especially careful,” noted MK’s interlocutor. – These are devices with batteries from 10,000 mAh – power banks, some phone models, laptops – with high-speed charging functions. Next, you need to carefully look at USB network adapters with multiple sockets for power charging (2.1 A). If several powerful consumers are connected to one such device, this is a high risk factor. Finally, these are any devices, including charging cables, that are physically damaged.

For example, a broken screen that seems harmless from the point of view of fire hazard can be dangerous, says Zhelnin. Not because the screen itself threatens to spontaneously combust, of course – but a damaged screen is a symptom of a “traumatized” device. And if the integrity of the battery or charging circuit is damaged during an impact, it may short out the battery.

“They often ask whether it is possible to leave the charger in the outlet when it is not in use,” the expert continues. – From the point of view of fire danger, this is probably harmless: an explosion is more likely to occur at high currents, and this is only when the device is connected. But, firstly, the adapter consumes at least a little electricity, so you can unplug it from the outlet in order to save some pennies on utility bills. Or for the sake of the environment. And secondly, I know many cases when the adapter simply quietly fails after a long period of idle operation. Quiet short circuit from heating, especially if it happens in the summer. This can be detected by the characteristic smell coming from the USB connector.

There are several “absolute indications” for repairing the device (in the case of a power bank, perhaps even for its disposal). This is the smell of burnt wiring from the gadget’s connectors, their melting, says the engineer. If such signs occur, you must immediately take the device out of service and take it to a service center (if it is a phone or laptop) or to a collection point for recycling.

“A common defect is poor contact in the power connectors on gadgets or power banks,” says Denis Zhelnin. – It seems disgusting, but harmless. But in rare cases, it is still possible to exceed the current strength, since contact is often lost, and a “hungry” device, when contact is restored, begins to charge at maximum currents. Therefore, in case of such defects, it is still worth replacing the connector.

Let’s add: sometimes the problem is not in the connector, but in the cable. Then the service will not be needed at all.

…I wonder what will happen if the cause of a fire or explosion is a power bank rented out by one of the growing “take your charge with you” services? Operators of such “sharing” announce almost Napoleonic plans for tens of thousands of devices in the coming years. But such services do not have civil liability insurance in case of explosion or fire. We can only hope for the Civil Code and the district court…