7 On Your Side: Lithium battery explosions unpredictable

There have been frightening reports of gadgets, like smartphones and hoverboards, suddenly exploding. The cause is often a small battery most people use in household gadgets.

Most batteries are perfectly safe, but there is a small risk. As 7 On Your Side's Michael Finney found out, no one can predict which ones may blow up.

Chris Raymond of Consumer Reports explains why everyday products sometimes turn into virtual bombs.

"They can overheat. They can burst into flames. What we're talking about here is essentially a sort of mini-fuel tank," Raymond said.

That fuel tank is the lithium ion battery. The batteries are powering more and more of our gadets, everything from electric cars to laptops to smoke detectors.

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"And even in those little greeting cards that you open up and sing songs," Raymond said.

The tiny batteries have been blamed for some big disasters.

Kieran Wallace, 14, of Pleasanton said she was opening an app on her brand new iPhone 6.

"All of a sudden it sparked," Wallace said.

The battery exploded and burned a deep hole in her hand. The phone itself blown apart, again by the lithium battery. Since July Kieran's hand has healed, but not her fears

"I was lucky it was in my hand, I could have been deaf or hurt my face ," Kieran said.

They brought the damaged phone to the Apple store. Employees took it away and gave her a new one. Apple said they take customer safety seriously. Kieran's phone was accidentally recycled instead of recycled.

"There are tons of kids out there that are using theses iPhones," said Kieran's mother. "The ion battery or lithium battery issues seems to be something that really need to be addressed."

Joseph Cavins lost his left eye when his e-cigarette blew up and shot metal into his face.

His attorney Greg Bentley represents nearly 80 people suing for e-cigarette explosions.

"You're basically playing Russian roulette," Bentley said

7 On Your Side consulted with University of California, Berkeley professor Nitash Balsara, a battery expert.

"Six months ago, none of us had ever heard of this. Now we're hearing about it over and over and over again," Balsara said.

"All lithium batteries have a chance of catching fire," Balsara said. "The problem is that one-third of the battery is a gasoline-like substance."

Packing all that energy into a tiny battery might be trouble.

The Federal Aviation Administration documented 25 battery meltdowns, or blowups, on planes and airports since January. The Consumer Product Safety Commission has more cases involving iPhones, laptops, flashlights.

The explosions are relatively rare, but always possible.

Finney: Can we predict when a battery is going to blow up?

Balsara: It's completely unpredictable. There is no way to look at a battery and say this is the one that is going to be trouble.

He said problems are rare. And so does the Rechargeable Battery Association. They said, despite publicity and video of isolated incidents, only an infinitesimal number among the billions and billions of lithium ion batteries on the planet pose a risk to consumers."

"How many is enough to cause a concern? To me, if it's your kid, one is enough," said Kieran's mother.

Experts say right now there is no alternative to the lithium battery that can be as efficient and effective. Researchers are hard at work developing a safer battery, one that doesn't use anything flammable to help create energy.