If you're ever worried your smartphone battery is a fake, here's a tip: don't bite into it.

A man in China has learned this lesson the hard way. He chewed into an iPhone battery only to watch it explode.

Video footage of the incident has been circulating online. The explosion goes off right in front of the man's face as he stands inside a local electronics mart. But amazingly, no one in the video appears to be seriously hurt.

The footage comes from an iPhone repair service called GeekBar, which is based in the Chinese city of Nanjing. The company originally posted it last week, claiming that the man in the footage was trying to test whether the battery was genuine or not. (Clearly it was real.)

Mishandling a smartphone battery is never a good idea. Over the years, lithium-ion batteries have shown their tendency to catch fire and explode whenever punctured.

That's because damaging a battery can cause it to short circuit and spark a buildup of heat, according to Battery University, a go-to resource on how lithium-ion cells work. That buildup can quickly cascade into "thermal runaway," forcing the battery cells inside to all overheat in a chain reaction.

"The temperature can quickly reach 500 degrees Celsius (932 degrees Fahrenheit), at which point the cell catches fire or it explodes," according to Battery University.

The key takeaway: don't mess around with your smartphone's battery. Other videos on YouTube have shown it's easy to trigger an incident when a lithium-ion battery is punctured. That can include stabbing one with a kitchen knife or shooting a smartphone with a bow and arrow.