You may be aware that there were some instances of iPhone 8 / iPhone 8 Plus batteries swelling up, so far very few such incidences have been reported. No explosion or fire just swollen batteries that also popped opened the iPhone 8’s front panel / screen unveiling the hardware inside.
The common issues that were reported with reference to iPhone 8 and iPhone 8 Plus were the phone split opened due to the battery swelling up. Fortunately there have been no incidence of fire or explosion.
Apple issues a statement saying they are aware of this issue and are working to know the exact reason why this happened. So far it seems there are just 6 reports of battery swelling and splitting the iPhone 8 / 8 Plus apart – from Greece, China and Canada. None from India as of now.
Also for now the issue seems to have occurred on a relatively small number of devices compared to the units sold. Hence it is also difficult for Apple to know exactly why this had happened, could be just random event as it is only on few.
Anyway Apple has admitted there are issues and are investigating.
Source : The Verge