Two types of battery failure were responsible for overheating batteries in Samsung’s Galaxy Note 7 smartphone.
The independent investigation by test houses TUV Rhineland and UL identified short circuits in the battery packs rather than problems with the charging hardware or software algorithms.
Samsung voluntarily recalled its Galaxy Note 7 smartphones after a series of battery fires in 2016. This was followed by an official recall in the US, and the phones were remotely restricted on the amount of charge they would hold.
The batteries came from two suppliers: Samsung subsidiary SDI and Amperex Technology, a Hong Kong-based subsidiary of TDK. The failures identified in one battery saw the negative electrodes being too long and bending, increasing the risk of a short circuit. In the other battery, an insulation layer was missing. Samsung has not specified which faults occurred in which battery, but acknowledged that they resulted from the design specification.
You can see the details at Samsung identifies battery failures in Galaxy Note 7 | EETE Power Management:
By Nick Flaherty www.flaherty.co.uk