Does Charging a Phone Overnight Cause a Fire?

According to SAEDNEWS, citing Hamshahri Online, despite scattered reports of smartphone explosions while sleeping, experts and mobile manufacturers believe that charging the device overnight is not inherently dangerous. However, this “safety” is conditional on following standards that ignoring them can turn a daily habit into a disaster.

In this report, we review the rumors surrounding “overcharging” and examine the real factors behind lithium-ion battery fires.

Refuting the “Overcharging” theory

One of the most common misconceptions is that keeping the phone connected to electricity after reaching 100%, causes extra current to enter and explode the battery.

Reality: Modern smartphones have internal protection circuits that cut off electricity as soon as the battery is fully charged. Therefore, a phenomenon called overcharging explosion in standard devices is practically ruled out.

Main suspects of nighttime fires

If there is an automatic cutoff system, then why are fire reports still heard? Fact-checking shows that the main cause is not the charger, but heat and low-quality accessories:

Fake chargers: Cheap, uncertified adapters do not control power fluctuations and are the main cause of sparks.

Heat retention: Charging the phone under a pillow or on a bed prevents natural heat dissipation of the device and leads to “thermal runaway.”

Damaged batteries: Batteries that are swollen or damaged are prone to short circuit during long charging periods.

Historical records show that sometimes the problem is not from the user side. The global recall of Galaxy Note 7 in 2016 proved that structural battery defects can be catastrophic even with the original charger. Also, multiple reports of battery swelling in older iPhone models show that battery aging greatly increases fire risk during charging.

Dangerous claim of overnight phone charging: “partially true”

Charging a phone overnight, if using healthy hardware, original equipment, and placing the phone in a well-ventilated environment, is completely safe. The danger appears when harmful variables such as damaged cables, fake adapters, or placing the phone in hot environments (like under a pillow) are added.

If your phone becomes very hot during charging or the battery is deformed, never connect it to the charger overnight.