Samsung details why the Galaxy Note 7 phablet shipped with the unfortunate tendency to catch fire-- an investigation explains the reason boils down to two distinct battery flaws, not a hardware or software issue.
According to the company the batteries had two major flaws. The first is a casing too small to actually fit the electrode assembly, leading to short circuits. Samsung suppliers realised the problem and replaced the batteries with a safer version, only in their haste they brought about welding defects that also lead to short circuits. Either way, the smartphones started overheating, and catching fire.
Samsung insists it built a stand-alone testing lab to look into all potential causes of overheating, including wired and wireless charging, the USB-C port and the iris-scanning functionality. TUV Rheinland was also hired to check if storage or transport processes affected the batteries.