A customer has come to you for help with his mobile phone battery. Earlier in the day, the customer realized that the back of the device was bulging out and opened the case to find that the battery was swollen. What is responsible for the swollen battery?
Overheating, overcharging, and just failing because of old age are possible reasons for swollen batteries. This is a problem with all Lithium-Ion batteries, and the battery housing actually swells as a safety measure to include the hazardous materials inside.