Although this article isn't 100% correct as to why cells can explode (more often due to user error), the important thing to take away from this article is: know your batteries. Stick with Samsung, LG, or [REDACTED]. http://mic.com/articles/135180/why-reason-vapes-hoverboards-and-drones-all-keep-exploding#.0lLkO4mib

There are a lot of consumers out there that are purchasing rewrapped batteries, such as Vamped, Imren, AWT, Efest, and the like...many of which have grossly inflated ratings on the battery wrap. There is an excellent article written by "Mooch", one of the vaping industry's most important people when it comes to battery safety. The article can be found at the link below. http://vaping360.com/there-are-no-18650-batteries-rated-over-30a-yet/ Vaping 360 is chock full of excellent articles like the one above. Below is a link to an image showing the true ratings based on testing from Mr. Mooch himself. Keep this link as a reference...