Seeing as there've been several MSM reports on Li-battery safety in vaping and peeps might be alarmed, here's a brief heads-up I've put together from the BBC and FDA that should put you in a safe place theoretically:
How likely is your e-cigarette to explode? | BBC
How to use e-cigarettes safely
Charge them only with the charger they come with
Don't leave them charging overnight
If batteries start to get hot, discard them
It's not a good idea to use them when charging
Do not modify products in any way
Do not use batteries if damaged, leaking or wet and dispose of them appropriately (via local refuse schemes)
Do not leave them plugged in once fully charged
Tips to Help Avoid Vape Battery or Fire Explosions | FDA
What Else Can I Do?
Until all vapes and vape batteries conform to strong and consistent safety standards, your best protection against vape battery fires or explosions may be knowing as much as possible about your device and how to properly handle and charge its batteries.
Make sure you read and understand the manufacturer's recommendations for use and care of your device. If your vape did not come with instructions or you have questions, contact the manufacturer.
Only use batteries recommended for your device. Don't mix different brands of batteries, don't use batteries with different charge levels, and don't use old and new batteries together.
Charge your vape on a clean, flat surface, away from anything that can easily catch fire and someplace you can clearly see it—not a couch or pillow where it may more easily overheat or get turned on accidentally.
Protect your vape from extreme temperatures by not leaving it in direct sunlight or in your car on a hot summer day or freezing cold night, and do not charge it in extreme temperatures.
Don't vape around flammable gasses or liquids, such as oxygen, propane, or gasoline.
Some images 'cause peeps like pics: