You need to identify the batteries that you have to see if they are safe to use in a mod. My guess, at that price, you got generic ICR batteries. If you can not identify their manufacturer they can not be considered safe. Hopefully they are the protected variety, as unprotected ICR batteries should never be used in a mod. Just because you haven't had a problem yet just means you've been lucky so far. As batteries are used and age, they become more likely to have issues such as shorting out and going into thermal runaway.
Batteries are not created equal in the battery manufacturing plants. Generic batteries are often the rejects of the better battery companies. Or they are harvested used batteries from old laptop computers, re-wrapped and sold as new. Either way, these are not the batteries you want in your mods so close to your face or hands.
Lithium ICR batteries are a volatile chemistry (meaning they release flames when they vent in failure). In this day of modern battery technology there is no rational reason to use a Li-ion ICR battery, protected or not. IMR and the new hybrid batteries are inherently safer chemistry batteries. They may still vent in failure, but only gas and not so dramatically or with flames like an ICR battery will.
Battery incidents are rare if common sense and safe battery practices are used, and if higher quality batteries are used in mods. Don't skimp money on cheaper batteries and a charger. They are actually the most important and potentially dangerous items in your vaping setup. It's not worth it to use poor quality batteries when your safety or home is at stake.
I recommend using only
safe chemistry,
high-drain batteries in both mechanical and regulated VV mods. These are the
IMR (Li-Mn) or
hybrid chemistry batteries. A list of these batteries are in the below blog:
BATTERY BASICS FOR MODS: IMR OR PROTECTED?
If you are so inclined, learn a little more about batteries here:
DEEPER UNDERSTANDING OF MOD BATTERIES
Rebuildable Atomizers are more advanced devices and require some basic homework to do safely. Knowledge of basic Ohm's Law and which batteries should be used are extremely important. Learn about these here:
INFORMATION RESOURCES FOR YOUR FIRST RBA
MECHANICAL MOD SAFETY GUIDE
