My standard rant on this subject:
There are risks with lithium-ion batteries if misused or short-circuited, and there have been several incidents and some injuries. But this is a common challenge across many types of battery-powered devices. We've all seen the media reports of cell phone batteries exploding or catching on fire.
Too many people are jumping into mechanical mods without understanding what they are getting into and not realizing it is not a care-free device like an eGo or
Provari. It requires more attention to details and a better understanding of all the variables. Too often people on forums say, " Mech mods are easy, just drop a battery in and go. I don't understand why others say it is not for beginners." Because if you don't understand all the things you need to watch for there is a serious chance of something possibly going terribly wrong down the road.
Mech mods are not learning devices. They need to be understood
before you begin to experiment with them. So far most novices have been lucky. However, some people don't check the batteries they use, don't know what resistance their coils are, don't know how to work an Ohm's Law calculation, etc, and nothing has happened, giving a false sense of security to others to try the same things, but all it will take is one bad coil or one bad battery to change someone's face forever.
When it comes to advanced mass marketed systems like cell phones and laptops and hybrid electric cars, the system designers of those products have taken appropriate steps to make them "safe" for uninformed end-user use. Purely mechanical unregulated ecig battery mods and uninformed end-users is a dicey proposition.
Most consumer battery operated devices are no where near the limit of the batterys operating limits. The high-end flashlights, ecigs and remote control toys come to mind as applications that really push the limits. With the RCtoys the device is physically far removed from the person so a mishap is inconsequential. With ecigs a mishap is literally in the persons face.
These batteries were not originally intended for what we are using them for. In fact, I have read that LG, Panasonic, Sanyo, Sony, and Samsung, don't even like the fact that we're using these batteries because they were not intended for single cell, unprotected use in any consumer device. The fact that they're available can be attributed to modders of flashlights, pen lasers, and bicycle electronics. A demand formed around those markets and it was filled by various folks, and then e-cigs came along and the demand skyrocketed.
A large percentage of the Samsung, Sony, LG cells are used in multi-cell configurations, i.e., battery packs in hybrid automobiles and cordless power tools. These battery packs have their own battery management system (BMS) that ensures configurable, consistent protection at desired current, voltage, and temperature settings to ensure long battery pack life.
BMS
As vapers, we are primarily using single battery cells alone by themselves, which often means we may be using these single cells at or above their recommended specifications for a single cell. This application is not the manufacturer's intended use for these cells. Add to these facts that some mech users using sub-ohm coils are using resistances that are way above the amp rating (continuous discharge rate) for the cell used, and you have the makings of an evening news report about an ecig that exploded in someone's face.