Samsung investigation blames batteries for Galaxy Note 7 fires

Samsung has completed its investigation into the Galaxy Note 7 smartphone-cum-tablet's propensity to burst into flames against the wishes of its owner and says that design flaws in both models of the batteries it supplied are to blame.

When Samsung first issued a recall notice for the Galaxy Note 7, following reports that early adopters were finding the device a little more spontaneously combustible than they might expect, the company was clear: It was the battery, not the phone, at fault. 'In response to recently reported cases of the new Galaxy Note 7, we conducted a thorough investigation and found a battery cell issue,' the company said, following what at the time was 35 confirmed cases of failure. 'We are currently conducting a thorough inspection with our suppliers to identify possible affected batteries in the market.'

The company's response was simple: delay the international launch, take back the units with faulty batteries, and replace them with a new non-flamey design. Sadly, this is when Samsung's luck went from bad to worse: Not only did the faulty batteries turn out to come from Samsung's own battery division, but the batteries it replaced them with also started exploding. The result: a total global recall of all Galaxy Note 7 devices and the cancellation of the product, with the market concluding the design flaw must lie in the phone rather than the battery.

Now, in partnership with three independent safety labs - UL, Exponent, and TÜV Rheinland - Samsung has announced that it was the batteries after all, and that the replacements also being faulty was a terrible, product-killing coincidence.

In the original faulty batteries, the problem lie in a deflection to the negative electrode and its tip being located along the curve rather than the flat part of the battery. The result: a short, causing overheating, swelling, and in some cases a nasty lithium fire. The replacement batteries were, naturally, checked for this fault and passed as perfect; sadly, they had their own issue, traced back to unusually high welding burrs on the positive electrode capable of pushing through the insulating tape and shorting the battery once again - a problem made worse by some of the batteries failing to have their insulating tape installed at all.

To reassure customers that their future Samsung smartphones won't double as incendiary devices, the company has announced a new product safety procedure which includes an eight-point safety check on all batteries, a new multi-layer safety measure protocol which includes software monitoring of the battery's status and stronger protective brackets surrounding the battery, and the formation of a battery advisory group including external advisers from industry and academia.