My suggestion to the OP: Be careful with your stuff. Take advice from everyone and remember - most of the "explosions" come from reckless and / or under-educated people or poor quality devices and batteries. If you take care of your stuff like you should be taking care of yourself, the probabilities of something happening is greatly reduced. Can you eliminate all hazards entirely? Absolutely not. EVERY MORNING you wake up and drive somewhere, the probability of a life ending accident is there. How about the weather?
What I'm trying to get at - is if you're fearful of your ecig, there are things you can do to lower the risks of bad things happening. A few of them are:
1. Use the proper charger for your batteries and place the charger and / or batteries in an authorized battery bag, on a flame proof container, and away from other flammable materials.
2. Use a proper charger to charge your devices (APPLIES TO 'BUILT-IN BATTERY MODS ONLY!). Using a 2Amp charger on something that should be charged at 1AMP or lower can cause the battery to heat up and may damage the cells in the pack. Once the cells are damaged, there's no going back, just go purchase another device.
3. If you're under-educated and / or have reckless tendencies - AVOID MECHANICAL MODS! If you are well educated and aren't a reckless person - then by all means, use a mechanical mod WITHIN LIMITS!
4. If you use a device that uses external batteries - DO NOT PUT LOOSE BATTERIES IN YOUR POCKET! Put them in a solid case that protects the entire battery! Don't put them in a "silicon sleeve", that leaves the side of the battery exposed and any damage to the wrap increases the chances of a short.
5. Keep your batteries out of extreme weather. Don't leave them in extremely cold weather and don't leave them in extremely hot weather. TAKE THEM WITH YOU - EVERYWHERE! Leaving them in your car in the summer may cause damage to the cells.
6. BUY PROPERLY RATED BATTERIES FOR THE DEVICE(S) YOU'RE USING! If you are planning on going cloud chasing, I suggest a 30AMP battery, hands down, every time, all the time. If clouds aren't your thing, and you're vaping at "reasonable" power levels, then shoot for a 20-25AMP battery. If you're using a coil / coil head rated above 1.0 Ohms, then a 10-15AMP battery should suffice.
7. KNOW YOUR DEVICE, KNOW YOUR ATOMIZER, KNOW YOUR BATTERY, AND KNOW YOUR LIMITS! This is self explanatory. But I'll delve into it anyways.
7a. If you're using a mod that runs in SERIES ONLY, then KNOW THAT YOU WILL ALWAYS NEED 2 OR MORE BATTERIES! Those batteries will need to be charged at the same time, used at the same time, and ALWAYS DISCARDED AT THE SAME TIME!
7b. If you're using a hybrid / pinless mod, make sure your atomizer has a protruding pin. Also, ensure when you clean your atomizer, you ensure there is NO DEBRIS LEFT BEHIND! No cotton, no wire clippings, no "gunk" - NOTHING!
7c. When buying batteries, use a marker and date them. Date the first time they were discharged and recharged. After a year or so passes, toss them and buy new ones. BUY THEM FROM A REPUTABLE SOURCE! DO NOT BUY THEM FROM EBAY, AMAZON, ETC! If they're still within reasonable age, but the wrappers are torn, scratched, cut, etc. Get them rewrapped ASAP! If the can (the silver part beneath the wrap), the positive ring, or any other part of the battery is dented, punctured, etc. toss it and buy a new one (or a new set if the batteries were paired up).
7d. Know your limits - what are you willing to do / what are your plans with your ecig, and what are you hoping to gain? Ask yourself this every time you do ANYTHING and all will be well.
Battery case(s): Chubby Gorilla Battery Case - Hard Plastic
There are other cases out there. imrbatteries and liionwholesale offer batteries, cases, and wraps should you choose to purchase from those places. I'm unsure about pegasusvaporacademy, as I don't shop there. I do suggest them though as they have a pretty comprehensive guide to batteries and battery selection.
Battery Bag: LiPo Safe Charging Bag
Battery Chargers:
www.nitecore.com
(1800-2100 size batteries - Use the i4/i8 Intellicharger)
(1800-2600 size batteries - Use the d2/d4 Digicharger)
There are others out there that have different features on them, like discharging, testing, etc of batteries, I'm just posting what I use as I don't have experience with other chargers.
Battery VENDORS:
www.liionwholesale.com
www.imrbatteries.com
www.pegasusvaporacademy.com