However, Samsung then switched to a different battery supplier (Batteries sourced from Amperex Technology Limited), but a completely different production flaw was introduced — which include some cells were missing insulation tape, and some batteries had sharp protrusions inside the cell that led to damage to the separator between the anode and cathode.
Infographic: Know What Caused Samsung’s Note 7 Explosions
Checkout an official Note 7’s autopsy report!
The Smartphone giant Samsung has confirmed that bad battery design, was a major reason for Note 7 overheat and fires, resulted from rush to release an updated version of the phone. The Galaxy Note 7’s battery (The one from Samsung SDI) was too large for the phone, there wasn’t enough room between the heat-sealed protective pouch around the battery and its internals, which caused the explosion.
They’ve also released an infographic that seeks to explain the whole problem in detail:
Samsung has concluded plans to assign teams to own the crucial final checks for each device’s core component, and also will put batteries through an 8-point test to prevent such occurrence. The tests include durability testing, visual inspection, x-rays, charge and discharge tests. Other tests to be performed include total volatile organic compounds (TVOC), disassembling tests, accelerated usage tests, and open circuit voltage.