3. Battery damage
Repeated exposure to elevated temperatures during charging accelerates battery degradation. Lithium-ion batteries, common in smartphones, are sensitive to heat. High temperatures can cause the electrolyte inside the battery to break down, leading to capacity loss, swelling, and reduced charge retention.
A swollen battery is a clear sign of damage and poses safety hazards, including the risk of rupture or fire. Users should avoid using devices with visibly swollen batteries and seek professional service immediately to replace the battery.
4. Fire hazards
Fire hazards related to smartphone charging are typically associated with battery malfunctions caused by overheating. When a battery overheats beyond its design limits, it can enter thermal runaway, igniting flammable materials nearby.
Soft surfaces such as bedding, couches, or clothing increase fire risk by trapping heat and providing combustible materials close to the heat source. Several residential fires have been traced back to phones charging under pillows or on mattresses. To minimize this risk, it is crucial to charge devices on stable, non-flammable surfaces with adequate ventilation.
