This morning at the Amerigo Vespucci Professional Institute in Milan, an emergency battery to recharge the phone suddenly exploded in a student’s backpack. It happened in a third class during the first hour while the kids were listening to a lesson in food science. Among the boys, panic exploded and many of them were dizzy. One teacher and four pupils suffered curable injuries on the spot, while two other 15-year-old students needed hospitalization. A girl suffering from previous pathologies due to severe psychological stress had a seizure. The school was evacuated due to the strong smell of smoke, but after a few hours, everything returned to normal.
Most power banks are built with Li-ion batteries.
Just like a tank of gasoline or a bullet in a gun, a battery has a lot of energy in it. If that energy releases in a way we don’t want it to be, a fire can occur or even an explosion.
It is the simplest way to understand why a power bank would catch fire and explode.
There are a lot of pieces and processes that go into making the power bank work. If any of those processes go wrong, there’s a chance for energy to be released.
The electrolyte solvent inside the battery is flammable. So when the battery can’t vent and build up pressure as the electrolyte burns, it explodes.
According to our previous research, the main reason for power banks exploding is the imperfect circuit. It is in lousy welding (sometimes with contaminants). Or it does not have the proper circuits insulated to prevent short circuits. It leads to overheating, then fires and explodes.
Of course, some small factories sacrifice battery quality to get a low price. It has the danger as well.
And as a user, it will cause a fire if you put the power bank in extreme conditions, such as leaving it in high temperature or humidity.
Although power banks seem dangerous by media reports, it is alarmist.
Undoubtedly, the power bank has a chance to explode. But the probability is pretty small.