ABC13 Eyewitness News was out in force yesterday, September 6, 2018 with two new cases of e-cigarette burns. Although in this case the batteries were apparently loose in the pockets of two men. Therefore the reference to electronic cigarettes in the breaking news headline is incorrect. The question then arises, what else caused the thermal breakaway?
Let’s Start By Reviewing the Technology Behind the Breaking News

We can safely assume the batteries were lithium-ion ones, since the manufacturer specializes in this type, and has an annual production capacity of 1,000 million cells a year. There are several reasons why lithium-ion batteries occasionally explode.
Firstly, a design fault can cause the electrodes to touch and short circuit. Secondly, a physical impact can damage a cell and have a similar effect. Finally, a faulty charger can overheat the contents leading to a thermal runaway. Let us consider what the two men told ABC13 Eyewitness News when they were asked to explain what happened. (The batteries in the photos are not the brand involved in the incidents).
What the Men Said About the Two, Unrelated Incidents

The first man was walking along on Austin street taking photographs when he felt his pocket heating up. “I grab the battery and it’s just burning my hand, and flames are just shooting out of one side. It burnt like the whole side of my leg,” he explained. The battery was not in the device at the time.
The second man’s experience was similar, except he says flames from the battery shot up to three feet in the air. Beyond this, the breaking news we have to hand is scanty. However, the case filed on their behalf says “e-cigarette components exploded and left them with extreme injuries.”
It therefore seems likely the second man also had the battery on his person, perhaps in a pocket. We first thought metallic objects in their pockets caused a short circuit between the cell contacts. However, when we realized the cells were Type AA, we decided the cause was likely battery failure for some reason we do not know.
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Preview Image: AA Batteries (Not the Brand in the Fires)